10uf capacitor code

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| September 12, 2018

This project allows wireless monitoring of up to 8 remote sensors using HC-12 wireless transceivers and a simple protocol, which supports outbound remote control and inbound status, and can forward and display data in the server.

platform. The project includes an Arduino-based remote MQ-7 carbon monoxide (CO) sensor and a matching HC-12 transceiver. The idea is to provide a central D1 Mini monitor based on ESP8266 with local display function and ThingSpeak interface for detecting odorless propane, butane and volatile liquids and fuels in facilities and even working or living places.

Arduino provides several MQ series gas sensors that can detect more common gases, including CO, propane, natural gas, and ammonia (MQ-37). Each of these sensors has a heating element with or without a defined power cycle change.

The Arduino-based remote hardware is responsible for the circulation of the heater and includes the DHT22 temperature and humidity sensor, which has been reported and can be used for CO sensor calibration. The remote control also provides the received request link processing through the HC-12 serial link. The HC-12 can be configured as any one of 100 channels and can operate at altitudes above 1,000 feet.

Referring to the picture on the right, I used a cheap upconverter to support the sensor heater switch hardware. Depending on the specific gas sensor used or the accuracy required, this may be optional. I included it because most heater control solutions either do not solve the voltage cycle problem, or they drop too much voltage to meet the sensor heater specifications, and the included price is relatively low. The converter shown works with 4.5 volt input and 7 volt output. Several other similar sensors only specify a 5 volt power supply and may not require any converters.

I used a pulse width modulation (PWM) scheme to change the heater/sensor voltage. This allows the resulting sensor voltage to be dynamically adjusted to any value between the regulator reference voltage and the maximum value available at the regulator output based on the sensor's input voltage and the required differential input/output specifications. When I was using the old LM317 regulator, more modern devices were also provided-defined as adjustable, with three or more pins, and the reference voltage was less than the minimum sensor voltage required. For the MQ-7 CO sensor, the voltage is 1.4 volts.

The remote sensor controller also provides sensor alarm trip settings, heater characteristics and alarm disable functions (input "?" on the serial link).

The sensor ID belt (marked "ID" on the schematic) is used to identify and identify the sensor through basic transmission control.

HC-12 channel and alarm trip can be configured from D1 Mini base. The original CO product, heater and alarm configuration, sensor temperature and humidity status information are returned to the base on demand via the link. All wireless communications are initiated by the D1 Mini controller based on ESP8266.

The controller is coded to provide a scheduler and WiFi uplink for the ThingSpeak platform. It uses serial-based configuration to set six application-based parameters and receives up to four features forwarded to ThingSpeak. The HC-12-based link can be connected to any sensor or other remote application that supports the link protocol. For the CO remote application described here, ThingSpeak related parameters allow the displayed graphs to include temperature, humidity and (raw) CO sensor values ​​and travel settings.

The D1 Mini base also provides an extended display driver that allows two-color LEDs to indicate operating status. There are fixed and flashing green and red indicator lights, corresponding to "active" and "in alarm" for each of up to eight remote sensors, respectively.

Common anode, dual red/grn LED display is coded according to the table and set and returned from the remote application as part of the response in function (id) 8:

Turn off when the sensor is disabled (channel set to 0)

Grn when active sensor is operating normally

When the activity sensor is in alarm mode, it will alternately display red/red

Red when the active sensor does not respond

Flashing red when the active sensor response does not match

Request number

At the base, enter "?" to return to the parameter list via the D1 Mini's serial link, and allow modification of ThingSpeak, network name and password, as well as plan and sensor configuration. In addition to the unique 3-digit ID set at the sensor, each sensor also allows a unique HC-12 channel to be assigned. Input channel 0 will set the associated sensor to "disabled".

The listed functions 1 to 5 use the request ID, and the text input is terminated with'$' (for example, enter 2, magicwand $, and set the WiFi password to "magicwand").

Four WrtKey entries related to ThingSpeak are supported in this list, allowing eight sensors to be forwarded to the ThingSpeak platform. The ThingSpeak website provides label and chart resources, as well as powerful processing/display tools based on MathWorks.

The listed functions 6-8 only use IDs and numbers with separators, for example:

6,5 Set the schedule to 6 minutes. (At least 3 minutes)

7, 3, 25 set sensor 3 to channel 25

8,2,75,0 trips sensor 2 to 75 and the heater cycle is set to "normal". The remote sensor heater cycle code is:

Normal (0) 90 seconds high and 60 seconds low

Short cycle (1) 90 seconds high and 50 seconds low

StatusOnly(2) returns 3 parameters

Off (3)

Function 9 displays up to six named variables. Each compatible remote sensor or application defines the parameter list displayed on the D1 Mini base, and provides the status and these values, and this information will also be displayed on the base. The library allows to modify this list and forward it back to the remote application. For CO sensors, this includes heater mode and alarm trip. For the modified loft controller, this list includes mode, fan priority control and loft temperature alarm trip settings. The schedule, channel, password and key are kept in the EEPROM of the basic controller. For the provided CO application, the stroke and heater value returned to the base will be returned and saved in the EPROM of the remote application.

The D1 Mini base is coded as a universal central dispatcher whose function keeps the base in a universal state, and applications can be added and forwarded to the ThingSpeak platform only through a serial link, without the need for code-based reprogramming. I hope readers can use it for their own remote applications. In development, I have converted my

App to use the ThingSpeak-based controller described in this project. Other previously released items, such as

or

Projects can be modified relatively easily to enjoy the benefits of the Internet-based remote wireless ThingSpeak display platform.

For the CO application, remote humidity, temperature, raw sensor data and alarm status (four variables) can be returned from the application, and forwarded from the base station to the ThingSpeak platform as needed. For the converted loft control application, the external temperature, fan 1 and fan 2 status and loft alarm trip temperature will all be forwarded to ThingSpeak.

If you have any questions or help with documentation, you can contact William Grill in the following ways:

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Adjust capacitor design

: MSI sent pictures and statements to dispute any claims that it has changed its 30-series GPU design. This includes four images on the back of the card, showing the configuration of the capacitor. The layout of MSI RTX 3090 Gaming Trio and MSI RTX 3090 Ventus 3X has 4 SP capacitors and 2x MLCC cluster, while the layout of MSI RTX 3080 Gaming Trio and MSI RTX 3080 Ventus 3X has 5x SP capacitors and 1x MLCC cluster. These are the cards that are actually sent to consumers and reviewers; there may be earlier variants, but they are clearly not delivered to anyone outside of MSI. These include the 6x SP-Cap card, the image of which was once posted on MSI's website but has since been deleted.

of

Just can't seem to take a break. of

The driven product is

Despite its limited availability, it is still on the market, but some customized models have stability issues.

Reports of custom GeForce RTX 3080 crashes began to pile up last week.

The root cause of the collapse may be due to the design and selection of capacitors. some

On this issue, the others remained silent. 

In short, there are two types of capacitors that can filter voltage. POSCAPS (conductive polymer tantalum solid capacitors) are larger and have a higher temperature tolerance, which means they are more expensive, but they are not competent at high frequencies. On the other hand, compared with POSCAPS, MLCC (Multilayer Ceramic Chip Capacitor) is smaller, cheaper and can adapt to higher frequencies. However, their temperature resistance is lower, so the frequency of cracking is higher. So far, user reports have shown that custom GeForce RTX 3080 models designed with full POSCAPS are more susceptible to instability and crashes.

MSI, reportedly

, Has begun to quietly modify the design of its GeForce RTX 3080 model. In fact, although some regional product pages are already showing new designs, MSI has removed the rendering of the backplane from the product pages.

The original capacitor layout on the GeForce RTX 3080 Gaming X Trio uses five POSCAPS and an MLCC array. The new design includes four POSCAPS and two MLCC arrays.

On the GeForce RTX 3080 Ventus 3X, MSI initially used a six POSCAPS design, which has been replaced by a new layout that includes five POSCAPS and two MLCC arrays.

It is unknown whether any old designs provided by MSI or other vendors are really popular. 

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nRF24L01 + PA / LNA module specifications appearance 

on the paper. Can various cheap sources in China provide wireless communications up to 1000m in a small package? Have various open source projects completed the hard work of software connectivity? It sounds pretty good! But if you buy and get

 1% of the range, don’t worry, because

.

[Oitzu] obtained significantly better performance from cheaper equipment, including providing better power, controlling noise, increasing shielding, and carefully choosing the correct channel. He claimed, "Through these modifications, I got a free line of sight of about 1000m from the module. In a forest with non-free line of sight, I measured a distance of about 270m, but this may not be the maximum range. I need further testing."

Modified nRF24L01 + PA/LNA module and

The software framework was used in another recent project of [Oitzu]: his

 They are responsible for transferring the camera images to the Raspberry Pi for later upload via the mobile network. Before making a simple modification, he was able to obtain the above 270m in the woods, but not even one-tenth.

In my opinion, the module works well and it is entirely the user's fault. They provided it with nonsense and placed it in a noisy environment.

Considering that these modules do not require any filtering of the power cord, and clearly state that they require more than 100ma of power for full power transmission, a well-designed power supply seems unreasonable, especially when you consider the nature of the data packet. Each of the devices needs to quickly switch between transmitting/receiving, which will cause serious damage to poorly designed SMPS power supplies. In addition, if you want the "1/4 wave" whip antenna to work properly, you need to install it on the ground plane (probably his work done by wrapping the entire object in aluminum foil), which is another problem if The module has been correctly installed in the metal box, and the antenna is only installed on the pass-through SMA, it means that it does not exist at all.

You are absolutely correct. When you buy such a cheap unshielded module, you don't need to buy a complete radio device, but only a piggyback PCB, you don't need to solder QFN ICs and perform all microwave RF matching.

It will not allow you to build a complete, powerful and compatible device without having to master RF knowledge.

If you are unwilling, please buy a certified shielded module with an integrated micro module, which will cost you about 100 times the money.

@fuckface When I wrote this article, it was mainly aimed at users who were unable to make the module work properly. Similarly, this article initially focused on shielding and repairing, and later expanded more errors that may occur.

Therefore, yes, you are completely correct that the unstable power supply is the user's fault, but this does not prevent the user from doing something wrong. :)

Regarding noise: Well, regardless of a noise-free environment and a clean power supply, the module cannot work normally without shielding. Not only is the module installed in a metal box, is it just a way to add a larger (volume) shield?

@cyk: Actually, there are some shielding modules that claim to be FCC certified, and you only need to spend 3 times the money. ;)

The ITU never intended to set the ISM band as a broadcast band. It is designed for short-distance data transmission.

@fface: (open!) You are right, you are wrong.

How many projects do we see here (quite savvy audience) that use nRF24 modules where people just disconnect it from the 5V power supply of the Arduino? Ton. How many things are blocking? No. Is it balanced? please!

The point is, if you buy one of these modules and follow the instructions (haha! get it!), you will get the same thing everyone has – a bare nRF24 module is stuck on a breadboard and the wires are Sealed in one of the cardboard boxes.

A better way to document may not be a hack in itself. But this can definitely improve the overall level of hackers. This is what we really want, right?

@Elliot: "Fuck" has nothing to do with "potty". Unless I am the one who did the wrong thing...

It is 3.3V. I am very lucky to be able to use the maximum power even with an unshielded external power supply. If I encounter a problem, I will do it... I haven't done a lot of RF tests yet, and I am still coding.

Bravely say everything I thought about.

By doing this to make the radiation pattern more directional, you may get a better range.

If you are interested in the 2.4GHz homemade antenna, please check the channel of "andrew mcneil" on YouTube. In fact, he has dozens of very useful 2.4GHz antenna structures and related videos.

Great video! Direct link:

I will have to browse this content and do some writing articles...any favorites? It's actually built?

I made a 915 MHz omnidirectional two-way antenna, which is suitable for Andrew McNeil’s 2.4 GHz two-way antenna (

) Car-to-home link for my Ubiquiti router. For the same gain, it works better than collinear, and is easier and more compact.

He uses lawn mowers or sheet metal clamps for repeated wire cutting/bending construction techniques that are very helpful. RG-402 semi-rigid coaxial cable is also easy to weld.

I have used antennas from time to time

(No direct link, please search for "antenna" in KB) A great success.

We made the Yagi antenna (simple and cheap) for testing. Yes, it further extends the range. But I haven't had any maximum range of tests. Maybe I should do that. :)

superior! Don't forget to test the forest range and sight line.

These radios are interesting because most of them are actually countervailing chips from China. They can be easily faked, but what's interesting is that real radios actually have design flaws, and because they meet specifications, there is no equivalent. Unless you use high-throughput ping-pong mode, you won't notice. The counterfeit will not speak to the genuine one, because one of the packages has been turned over! I recommend always buying them in pairs until you get a completely error-free software...

I use RFM75 or RFM73, which are clones with the proper bits for the node. However, I use NRF with a large PA/LNA antenna in the center to get a good range. What really annoys me is that I cannot use automatic ACK between them. Otherwise, Hoperf will not use LNA and external antennas to create a "high-power" version.

The NO_ACK bit can actually be selected by bit 9 of the 0x0C register in bank 1 (also called "compatibility mode").

No need to change the bitrate to 250K...this alone can greatly increase the range.

Where's the antenna? Is it targeted and matched?

Tin foil shielding is very interesting to me....

A few years ago, I conducted some tests to get the maximum range of some XRF radio modules with standard whip antennas running at 868.3mhz. I found that if I set the wireless baud rate to 1.2k, when the antenna is aligned correctly, I can reach 3.4km, of which 1km can send out a good signal.

I also made a quick video, by holding a wireless error detector next to the transceiver, sending it repeatedly at 250k and then sending a packet at 1.2k, showing the difference between how many transmissions:

Of course, slow speed can improve a lot, but for the same data, you will consume 200 times the energy! Some people seem to miss this and just reduce the radio to the lowest data rate for maximum range.

Radio novice here.

But I get more power at a lower rate, and I think it can be balanced. Just like text messages or calls. I have a hard time finding this word.

It can be roughly balanced indeed. A higher data rate proportionally requires more bandwidth, a larger bandwidth proportionally increases the received noise, and higher transmit power needs to be overcome, which ultimately results in the power * data rate product for a given path and a given signal-to-noise ratio In terms of approximately constant (becomes 1 / (error rate)). Suppose the receiver bandwidth decreases with the data rate, but I don’t know if a module like this does that.

@BrightBlueJim is correct. As long as you can still increase the power or decrease the bit rate, you can trade them with each other. But in reality, the situation is different: shorter data packets with the same SNR have less chance of being affected by other transmissions in the shared frequency band.

This is why people tend to use RX power to the maximum and then reduce the bit rate only when the SNR/range is unacceptable.

Thanks for your quick reply! I need to make sure that my assumptions are correct. :) I know that every product may be different.

Thanks for your clarification, although the XRF module I run on 2v-3.6v consumes only 36mA during full power transmission, so there is not much energy when transmitting slow data over long distances.

If you use a lower bit rate, the transmission will take more time and therefore will consume more energy. Every bit you transmit consumes more energy.

On most of the transceiver modules I purchased, nRF24L01+ is an unlicensed clone, not produced by Nordic Semi. The weakness of these clones is that they are extremely sensitive to power supply noise. The 50mV pp switching noise is enough to reduce its usable range to a few feet. Moreover, if there is a PA/LNA, then... you know their evaluation of garbage entering and garbage exiting.

For modules without PA/LNA, I first soldered the 10uF ceramic SMD cap directly to the VCC/GND connector pins. This is helpful, but it is usually not enough to supply power with a normal switch. Instead of increasing the capacitor, I connected the VCC and GND of the module through a 1ohm resistor. Combined with the added cover, the Pi filter can be made more effective. This always solves the problem and reaches the expected range.

For modules with PA/LNA, I use 100uF and 2x 0.1ohm. In addition, I usually add an LC Pi filter to the switcher output.

It should be regarded as the knowledge required to use the nRF24L01+ module.

Chris C, hello, can you better explain or plot the connection details with the 1ohm resistor and capacitor cap. I mean what is connected where..

Thank you

Chris C. is absolutely correct. We actually used these clones in production, and through a lot of tests, we found that by properly filtering the power supply, they are very useful in the range of up to 250m. For ordinary modules without series resistance, we have achieved better success by using 22uF tantalum instead of 10uF ceramic. Similarly, for PA/LNA, we use 47uF tantalum capacitors, if it is on its own dedicated 3.3v linear power rail, then it can also be reduced to 22uF.

One thing we don't do, because this never worked in production: please use a switching power supply nearby or power these clones. You are lucky to walk 10 feet! By adding a shielding layer and a real ground layer and an additional LC filter, RF can work normally within a range of 100m, but it will still fail. However, the additional ground plane or the production cost of placing OEM parts on the PCB but requiring external connectors is not worth it. The battery life has been hit little, but the alternative methods have gotten worse...

"Wrap it in plastic wrap"-not sure this is the best idea...

Probably not the best. But it needs to win the title of "ugly fix". ;)

However, despite this, it has worked flawlessly since a few months.

Next is the LDO switching regulator?

This will not save you from having to filter power as Chris C. said.

If you look at the LDO ripple rejection at high frequencies, you will find that it is very bad, so a simple filter is better at attenuation.

This is what I learned from using these things:

1. Pay attention to the power supply: Decouple your LDO correctly (it needs 1-2uF ceramic, not 100n + 100u electrolysis!). b. Use a decoupling cap (1-2 uF ceramic) next to the module.

2. Use a linear power supply instead of a switching power supply

3. Don't use SPI polling like most libraries to check if there is a received packet. This will increase noise. Use IRQ pin

4. 250Kbps is really amazing

5. Pay attention to cheap connectors and solder if possible.

6. It is best to place a large ground near the module, for example, place it in a metal box that is in good contact with the antenna ground.

7. Do not use long wires on the module, especially cheap things. look here:

This is excellent advice. I myself encountered a problem when using some shielded versions of the PA + LNB version. I thought that ordering the shielded version would solve my problem, but it is not the case.

I use the following module boards to connect to my unit:

My problem is that the module is only sent when I hold the unit in my hand, I think it has something to do with the grounding of the module. When I held it, I got an excellent range. To sum up, I will try to add some ceramic capacitors (

), do I need to add them to the ground and vcc on both the radio and the modules used above? Regarding the need to hold the device, how can I solve this problem, my application cannot choose a metal box. Is there anything else I should know?

Any help or suggestions would be greatly appreciated, I am a newbie in electronics!

By the way, please be careful to use the large ceramic caps (MLCC) on those OLD 1117 regulators shown in the link. This regulator is very old and was designed before MLCC, so it would be unstable without some minimum ESR. It only applies to electrolytic covers. The part is very cheap ($0.03 from China), so the price is cheap.

I read the data sheet and understood the problem with the original part based on LM1117, so I designed a series resistor. Just for the hell of it, I tested these outputs when I used them in the design.

Go to the bottom of the page:

The oscilloscope image with sawtooth wave is because the ESR of the MLCC is so low that the voltage regulator starts to oscillate. By adding the series resistance (1R) of my design, the output will meet expectations.

Daily experience: Don’t mix old regulators with high-value ceramic bottle caps without reading the data sheet-it’s best to base them on their data sheet. Use chips designed in the last 5 to 10 years.

The Y5V dielectric of your second link capacitor is very poor because their value drops to a small percentage under bias. You need X7R or X5R dielectric. Generally, when using decoupling capacitors, keep the leads/connections very short, because the inductance of the leads will increase the impedance.

Hi @fpgacomputer,

Thank you for your reply, I think I understand most of it:-/

So, considering that I also use linked modules, how would you set it up (eg capacitor/resistor). I'm new to the electronics industry, so the simpler the better (I hardly understand decoupling, oops). That said, I spent several weeks trying to make things work properly and pulling out my hair. I'm really not sure why holding my modules can make them work perfectly, as far as I read it might be related to its foundation? By the way, I currently connect the module to the 5v line of the Arduino Uno.

Any help would be greatly appreciated.

It sounds like you are making a top-notch antenna. Sorry, I can't provide more.

Well, thanks, I guess so? :)

@Bogdan any ideas?

Maybe put some pictures somewhere to see? In addition, do you start with some basic codes that you know are valid?

Hi Bogdan,

I can put some pictures, but the wiring is very simple. I have basically connected the adapter board to the Arduino and plugged the shielded/unshielded NRF into the adapter board. Use the unamplified version to confirm that the code works perfectly.

Like I said, if I hold the module, the range is great and the gearbox is perfect; if I don’t think this is bad, the gearbox is very slow, do I think it needs a better foundation?

I am a little confused about the decoupling/resistor business, do you suggest that I put a small capacitor on the radio and circuit board, such as 0.1 span gnd/vcc and a 1k resistor, and where to lead the wires from the Arduino to the adapter board ?

Sorry, sorry!

@Bogdan Any ideas, I'm really dead :-(

It's hard to tell without some documents and pictures. First, you might even find the error yourself.

Bob, do you know why smaller ceramics are better here than larger electrolyzers? It seems illogical...?

Sorry, Bogdan, not Bob...!

Not Bob, but they have better high frequency response.

Sparkfun gave a good description of RFM69, and the same description about antennas also applies to nRF24

See how they have a circuit board with good decoupling function next to the module? Most people will skip the circuit board and connect the module directly, skip the capacitor and use thin wires. In addition, the PA version of NRF consumes more current than RFM69 (low power).

Laura

If the design is not good, Laura will not be able to save you. The article pointed out that "may reach 1% of this range" pointed out some basic problems. Of course, you can always get a bad module, but it usually looks ok.

Well, I have several modules with very small antennas, and their forged range is only half of that of PC board antennas.

The bit 0 in the register 09 of these nrf24L01+ chips is marked as RPD-Received Power Detector. When the strength of any signal received on the selected channel exceeds -64dBm, the bit will become 1 when the RX mode is turned off. Why not use this function to quickly scan the entire channel range, find an empty channel and send a command to the receiver to switch to that channel?

I thought everyone knew that each IC and each module needed its own power filter. Even sockets designed for logic chips have built-in 10nF or 100nF capacitors between the Vdd and GND pins...

I tried. Quick scan is not a good measure. I live in an urban area and there is a lot of WiFi around. Using this method, I can find something on each channel. I find that the one that can provide better results is to switch to wifi channels 8-9. Reason: Most APs use channel 1 by default, and some use 6 or 11. They are non-overlapping. If no one manually sets their AP here, 8-9 should be the quietest area.

I have some, and I seem to be lucky because they seem to be real. They have built-in antennas and don't have a large range, but they have enough range for the applications I want, often monitoring plant water levels and the like.

One thing I want to know is whether these ultra-cheap "clone boards" are really close to the specifications they should meet in RF applications. Is the impedance of the RF trace controlled? Are they not even willing to use test strips to check the impedance obtained in the PCB fab? How is the distribution network designed for these boards? Have they actually performed a proper PDN analysis and ensured that the impedance of the grid is suitable for the current task?

In your dreams... they even started to take out components from the cheapest modules.

It may be that these modules were cloned from some better-designed modules, but I can be sure that there are at least 3 designs for low power and 3 modules for high power. So, maybe not.

If you want a better product with a lower price, check out HopeRF modules, they have RFM75 (newest or old 73). They are indeed compatible with real NRF (not compatible with fake ACK). You can also get them from some large publishers, not from nonsense.

Hello, for the problem that the module only works when you hold the device with your hand or touch the IC with your finger to work normally, I solved the problem by reducing the power consumption to the lowest radio. setPALevel(RF24_PA_MIN); and reached a range of 250 meters, I use nLRF24L01P PA + LNA :-)

It is strange, what type of whip antenna did you use in your test?

By the way, anyone who has tried E01-2G4M27D (

)?

I just managed to extract 700m (through trees) from these modules, but it took 3 days of experimentation. Thank you very much for the above comments, indeed, this particular thread may be the best resource to make the high power module work properly. The best solution is to use the old 317 with 3.3V voltage provided by 330R/560R. There are 0.1uF and 10uF on my radio module. 317 is the standard schematic diagram in the data sheet, for example, the input (470uF) and output have maximum limits of 0.1uF and 10uF. I also wanted to delete a variable, so I added a 2 meter cable to the antenna (you can pre-make it on eBay). I also have small ferrites on all data lines, but I'm not sure if these are needed. Power seems to be critical. I tried many switching regulators, including regulators up to 3A, but without success. There are multiple LC filters on the input and output of the switch. Place the switch under the load (10R) and observe the waveform on the CRO until it stabilizes. Still no luck, but strangely, when I connect the switcher in parallel with the linear regulator, it works (I know it's a bit anti-throat). If the linear reg is connected in parallel with the output after the additional LC filter, it works normally, but it does not work before these filters. I want to know whether the radio module will produce high-voltage spikes, and the linear regulator will suppress these spikes?

Another interesting thing is that if I try to power the module through a large number of capacitors, I can replicate the failure even at the lowest power setting. It seems that if the module is not satisfied, it will fall into self-oscillation and consume a lot of power, and then shut down.

I also tried another experiment-tap the antenna with a rock-solid sound for one second and extend it for 2 meters, but if the wire is removed and the antenna is directly connected, about one-tenth of the ping will not kick in. I think this helps to keep the antenna away from the module and arduino. I suspect that the ground plane may also be shielding the module (same as the tin foil trick).

If a wire is used as an antenna, there are two types, male, reverse male and ditto female. Not sure about the correct terminology, but one type seems to be used for radio modules and one type is used for home router wifi antennas, and they are not compatible. However, if you buy the wrong adapter, you will get very few adapters.

In any case, LM317 and antenna can work normally.

In my case, there is no problem receiving data, but to transmit anything in any range, I have to touch the antenna, as long as I keep touching it, everything on the sender can work normally. I have tried shielding, using power, making modifications, etc., nothing helped except touch the antenna with my fingers.

This website seems to have been offline for several years. This is an Internet archive for future clickers:

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When working on a project recently, I needed a capacitor of about 1000μF and studied my parts collection carefully. No luck there. At that time, I usually browse the garbage electronic products and computer motherboards I collect,

As far as I know, it has been around for a long time. It's okay, I think. I will go to RadioShack and...

Now, over the years, I have been accused of many things, but "deep" is certainly not one of them. However, at this moment I can only say that it is an existential crisis. Without RadioShack, at least not my status.

Even the hacker space within my reasonable driving distance. Of course I can order them online, but everyone wants to sell them in bulk, and it will take at least a few days to ship them. How many days? Who knows where I am interested in a few days. What should I do under these conditions?

Desperate times require desperate measures, so I got in the car and drove to the only place I knew I could buy with cheap electronic components: goodwill.

If you are not familiar with goodwill, then this is a second-hand store that sells all kinds of goods, usually just for a little bit. Although Goodwill’s inventory is usually mainly clothes, there is an electronic equipment section in the back corner of every location I’ve visited, where there are a bunch of worn-out VCRs, audio cassettes, tube TVs, etc. Basically, an old consumer electronic product, the owner feels sad that it cannot be thrown in the trash: you will find it here. Of course, goodwill is not unique in this regard. If you have a second-hand or thrift store in your area, they may be similar in size.

In a world without RadioShack, I suggest you become familiar with these types of stores and the products they tend to trade. If it is not something you cannot avoid, you should probably check it once a week. Because if you are not lucky enough to live in the hot spots of manufacturers or hackers, and are proud of not being able to choose junk, then a store like this might now be your RadioShack too.

During the journey, I found what I wanted without a doubt. There are many VCRs and radios around, each for no more than $5. If you are looking for a good source of through-hole components, then you may want to use older and cheaper hardware. High-end equipment will more likely have been converted to SMD components or other miniaturization technologies, which may make salvaging parts from them even more annoying.

If you want to rescue parts from old electronic products, you need to master the desoldering technology.

, But at a minimum, you will need some desoldering wicks. If you want to make yourself easier, buy a suction cup, or even better use a desoldering iron.

As far as I am concerned, I am very lucky. The VCR I chose is easy to separate and provides power on a removable module so I can remove it directly. The inside of it looks a bit annoying, most of the inside of the machine is covered with some kind of sticky yellow fluff. If I had to guess, I would say it came from the smoker's home. But for $3, we cannot be too picky.

The power source is always a large number of electrolytic capacitors, and it only takes a few seconds to determine a 1000 F capacitor that does not seem to swell. Keep in mind that the hardware you are using can be suspicious, and perform a careful visual inspection of all parts considered for inclusion in the project.

After removing it from the PCB, I can check it with a multimeter and find it is about 900 F, which puts it within the tolerance of this capacitor.

, Make sure you don’t run into all the troubles

In the end, I only spent a few dollars to get the capacitors I needed (plus other passive components and component loads pulled from the VCR). Of course, it is a better option than ordering a single capacitor online, but I still avoid it. There are no local electronic parts stores in my area now, and it may be time to bite the bullet and load a lot of passive components from eBay before I really need them. But having such a contingency plan will never hurt.

In this dystopian RadioShack wasteland, where do readers get the components? Are you lucky enough to live in an area where you can source parts locally? Do you want to buy in bulk online, just want to be able to predict the required parts? Maybe you are full

And how to build everything with everything in the trash can?

Let us know in the comments,

.

Desoldering is how I often spend a Sunday afternoon. No parts have been used. Or any parts solutions I purchased?

When I was young, I stopped at a TV repair shop (remember when the TV can be repaired?), then picked up some cases that were considered uneconomical to repair, and stripped their parts. I still have some parts.

Although I did get one of them to work and connect to my ZX-80.

The solution is to sort and store the parts well so that you know where they are when you need them. A few days ago, I needed a non-polarized 150uF capacitor. Guess where it came from?

When I started using electronic products (there was no nearby store and there was no online ordering situation), I did this, but now I understand which parts are on a typical TV PCB, so I only keep the assembled ones PCB and know where to find the parts I need. It is also a good source of resistors that can be used for load testing. With a voltage of up to about 12V, you can also solder on some leads and pour the resistor into a bucket of water to produce almost infinite wattage without creating a noisy fan or messing up the heat sink.

Does electricity flow through water instead of resistors?

Some will, but so what? Still a burden. Tap water is not a very good conductor, especially compared to 10 ohm resistors.

For a long time, salt water has been used as a ballast resistor for welding.

Once we did this deliberately: 0-100V / 2A PSU for load testing. We put two stainless steel plates (20*20cm) into a bucket of tap water. Change the load by changing the distance between the plates. Facts have proved that "stainless steel" will not maintain this state in this case. The contents of the bucket became reddish brown soup.

You may not know that not only are tube TVs still being repaired in some parts of the world, but when they eventually break down completely, all components have been desoldered, and the copper wire coil on the CRT tube is also unwound and carefully re-wound To speakers and electric motors. The market is not far from my home, and I see them doing this by hand from time to time.

Then reassemble some of these parts into the karaoke system and audio amplifier. If you understand what I mean, you can also buy the logos of major electronic brands. Sometimes, you will see something interesting, such as a Toyota speaker system or Microsoft certified pants.

I wish I could provide you with photos of Microsoft certified pants. Many jokes about security holes and patches. Well, we all have regrets.

Google told me that Microsoft made mobile phone charging pants in 2014?

I will definitely grab the photos of MSCE pants, I have a chance to get it next time :)

If you have never used any cleaned parts or new parts, then a good solution is to start a new hobby in electronics.

I occasionally make some basic audio amplifiers from donors. However, the loss of the "cheap" Radio Shack prototype board will be unbearable. Our Radio Shack just closed recently.

Since entering a hobby as a teenager 30 years ago, I have been repairing parts and electronic products that are damaged and unnecessary (man, it’s really been 30 years!?). Over the years, I have used these parts many times for maintenance and construction projects. My capacitors and resistors are organized in drawers according to the 10% series of labels, so when I need a part, I can easily find the right drawer. Whether the drawer actually has the parts I need is another question altogether, although I did clean out the small parts of the local Radio Shack when they went out of business, so my equipment is quite complete these days.

Our last Radio Shack was closed and they did not bother me. When I sent there to get PL259, I found it was closed. I have ordered some, but I won’t get it until next week. sigh.

At a certain point, we have 5 in the area. Plus three private suppliers (all are long gone).

Yes, the radio shed will also leave our area. I didn't expect good intentions, good ideas. Fortunately, there is a 45-minute walk to backup Skycraft.

Edison once said: "To invent, you need a good imagination and a lot of garbage." Or at least goodwill.

"There is still a lot of rubbish." Or at least in good faith. "

Are you a little redundant?

B ^)

This is the point. They store garbage for you.

I often use Mouser and other products, but sometimes you need it now. I only strip the parts when I need it, and don't try to fill the storage box of stripped parts.

You must live in the Orlando area.

I went to Disney earlier this week and ended my trip by crossing the town to Skycraft on Tuesday morning. They saved us 150 dollars in about 30 minutes. I have been there for the second time. Are you 45 minutes away? you. lucky. Bastard.

Yes, Orlando, less than 30 minutes from Skycraft. Living in the San Jose area in the past was a dream come true at least then. The happy aircraft is getting closer and closer to me. I will jump around more often and get the $150 discount too often. If you visit again, there is a great RC shop near Skycraft, which has more fantasy than before with RC airplanes hanging from the ceiling. gravesrc.com is worth a visit just to see what they have.

Reused parts can be compressed, but electrolysis is the most difficult part to remove.

To be honest, I used to think that salvage was the best thing ever-now I realize it is a waste of time. For 99% of passive components and ICs, if you include the time spent, buying new products will only be much cheaper. Unless you need something in the next few hours, digikey and mouser will provide reasonable prices and 2 days of turnaround time. This is the real need.

Having said that, I am totally willing to save linear moving parts, certain motors, lens components, vacuum chambers, etc., simply because they are hard to buy and expensive.

I totally agree, except for the two-day delay that allowed me to get out of trouble and enter another work week. My inspiration is almost impossible to continue working for another week.

Taking the time to redesign the way of inspiration can be a valuable investment. If you can wait a moment, you can use some very cool options. For example... if you are inspired, you can sit down and design a small PCB instead of trashing. Order PCBs from OSH Park, then order parts or put them in the shopping cart for batch processing with the next inspiration part. You can research each inspiration and take them all the way to the prototype. Later, the PCB arrived, and I found it exciting enough to make the project inspiring for assembly and testing.

Thank you macegr. I have no doubt that you are correct. If I can find a power reflow oven that is easy to use. Seriously, I saw the wisdom to change the project steps to get closer to the half-life of my inspiration

Sometimes it is difficult for me to be motivated. I follow Magler’s advice. PCB design is a useful skill, and you will eventually get a higher quality skill. You can also prepare some different designs anytime and anywhere at any given time, so when inspiration strikes, you can make any design. When submitting a PCB order, you will also submit an order for any missing parts. After a few weeks, everything is there and you can

I use a $20 electric furnace to reflow SMD components. You don't need a fancy oven controller or any such nonsense. Obtaining some low-temperature bismuth solder paste will also make it easier because the circuit board will not become hot before reflow.

Where did you rescue the vacuum chamber? ? ?

When I was very young, the salvage and sorting of parts made me familiar with them easily. Sorting resistors as early as possible helps me learn color codes.

Failed fluorescent electronic ballasts are a good source of high voltage components.

47 microfarad 250v and 50v electrolysis

.0056, .0082 micro Farad in 1250V metallized film

.24 micro Farad under 400V metallized film

1 microfarad under 200V metallized film

D13005 400V 4A switching transistor

and many more…

Just make sure not to separate them (if they are pre-1980 products), because they may contain PCBs, and PCBs are a shortcut to cancer.

Polychlorinated biphenyls are rare in consumer electronics. They are liquids and are usually only used in high-voltage (1000 volts and above) capacitors and transformers. The PCB capacitor will be a completely sealed metal unit whose size is much larger than an electrolytic capacitor with similar energy storage.

I think before 1980, there were almost no electronic fluorescent ballasts. Moreover, the cover containing the PCB is not mounted on the PCB: -) It has studs for mounting and is a phase compensation cover for the magnetic ballast.

Electrolysis is safe in this regard. But I will avoid saving them because they have a limited lifespan.

Unfortunately, this seems to be a self-fulfilling death spiral. Our local electronic parts have been folded, except for one place, all other places are still reserved for tax exemption. Inventory will not be replaced, but if you need an IC that has not been produced in more than 40 years, it is an ideal choice. When you move to 74 {LS, C, ACT, etc}, there are some pin assignments that are different in the 7400 series.

I think there should be an email distribution list of hackers in your area, in which case you can contact these hackers. I'm sure that dozens of people are close to me, and there may be things I don't have. If the "neighbors" website operates in your area, you may only need to make a call there.

CraigsList?

I think it must be based on push. Of course, I don’t go to CL or Hackday forums every day and check if I can give up my stuff, but if there is only my local hacker neighbor’s email list and it is displayed once or twice a day, I might look at it and see if Can help.

Every night I get a summary of the neighbor’s website, usually I look at it to see if I can help, or if there is something interesting in the classified information. A few weeks ago, someone wanted to cut it again with a tile cutter. I drag it out, set it up and let him know. The next day, six packs of beer appeared magically.

I remember that when the category column was opened in Hackaday, it was when there was a forum. It didn't take off at that time, but I want to know if the weather is right, and then try again.

You mean...

?

Deprecated! = Dead

Sorry to report your comment. The hovering thumb strikes again. Must move dam report button

Don't worry [Neorpheus]!

If you want to sell, there will always be a Tindie Flea Market.

I was lucky to keep driving distance with Tanner Electronics, and even luckier to have a girlfriend who knew the store and knew the parts I needed.

Tanner and Unicorn are a beautiful combination

Tanner Electronics should automatically calibrate to the church

It's okay they are too different. Electronic stores sell real things!

Almost my entire electronic lifestyle started with salvaging parts. The university where I live regularly conducts auctions, which is a gold mine of old computers and printers. However, when someone decides to clean up the laboratory, they usually put something surprising. Sometimes merchants will conduct sales or auctions. The advantage here is that you are not limited to consumer electronics.

I find that it is best to leave it on the circuit board until needed, unless you find that it requires several hours of desoldering treatment. The crucial question is to avoid getting yourself into trouble and let yourself be addicted to it. And I learned a lot of reverse engineering, and these interesting things came out my way.

This is very similar to the metal inventory you have on hand as a mechanic. You have lost the motivation to drive to the store or place an order. It's great to have an idea and complete the part design in a few minutes.

Now, my goal is to eliminate half of my garbage reserves. Maybe I can sell a 20-pound electronic trash can on Ebay?

I bought a miscellaneous electronic watch for $10 at a college auction.

One of them is a simply constructed "rodent respirator" that may be used on laboratory mice.

Another auction participant offered me a dollar, and I accepted it. A friend of his recently killed a mouse at work, and he planned to "give it away" to him.

In the same auction, someone bought an HP server in a half-height rack. He took out what he wanted, and I helped him carry the (heavy) relic into the trash can. When the shelf was upside down in the trash can, I noticed some neat casters on the shelf. So I removed them and built a furniture cart with 4 2×4 pieces, a piece of plywood and a carpet remnant.

Did you save the shelf? They are so useful!

I wish I had...

Especially the quarter and half height. 2/3 is also very convenient sometimes.

Is that for mouse-to-mouse recovery?

A date that will live in shame...

;)

When in college, some of my friends would go out and be bombed to commemorate "Pearl Harbor Day."

Ren: UM-Rolla TJ4N? If not, Pearl Harbor is of great significance to that school’s dormitory. The annual party started when the floor failed and fled the school, and a barrel of beer was set up. When I was a freshman, the attrition rate in the first year was about 50%. Unforgettable time...I am very happy to survive. I don't know whether this tradition will continue.

If this is a zombie apocalypse, compressing parts is a good choice.

However, as long as Digi-Key and Tayda Electronics are still running, this can be done. There is nothing better than getting what you really need at a reasonable price.

If I dismantle the old hardware to find parts, I will have to violate the minimum wage law and seek help from the State Labor Commission.

But you will learn a lot, or you can learn a lot. This will be a cheap education. Save Digikey and Mouser as unavailable content.

The relative value of time, labor, and money is very different for different people in different life situations.

For a child who does not have a stable income, the summer vacation is long and he is interested in DIY electronic product compression parts, which makes sense.

When that kid grows up to have a high-paying job and a family... free time is limited and most parts are cheap.

Later, he retired and had a lot of free time, but his income was fixed.

Of course, this model only applies to people living in wealthier developed countries. For some labor, it is always cheaper than money. For people living in wealthy developed countries, this may even be the case, but these people may have greater life problems, and these problems should be solved first before buying hobby accessories.

The problem is "reasonable expenses". It is not satisfactory to pay 18 dollars in shipping for some parts worth only 3 dollars. Therefore, if the item can be delayed, I can order it on AliExpress (price is 100 for one price) or try to stack scraps.

The goodwill around is often weak in electronic products. I think this is because our recycling is very easy, so people will not hesitate to bring e-waste to the transfer station. It doesn’t cost anything, or it’s already paid in our county tax bill, so people just do. Trash bins with e-waste are sometimes worth drooling-I have seen piles of server-class machines there, and if there is no "No Salvaging" sign and a watchful waiter, I would score a few points for scrapping.

Say hello to employees in different locations, and then for a short time (the boss is not around-you will know who he is then), they may surprise you. Then leave a "doughnut fund" of about $.

But if it’s busy, go ahead, they don’t want others to see others busy.

I think I have never seen goodwill for outstanding performance in electronics. They are usually about 95% of clothes, with a row of shelves in the back filled with dishes, lights, VCRs and alarm clocks. The advice on second-hand stores is reliable, but in my experience, things in non-chain stores are usually cool.

I know that an agreement can be reached to obtain items from the recycling center. However, you may have to register some kind of company.

I suggest people try to locate goodwill not far from one of the higher $$ real estate areas in their city. There is such a company in our town. I not only found many printers, scanners, VCRs, stereo receivers, amplifiers, etc., but also found many excellent working electronic devices, such as my latest Onkyo amplifier, TiVo activated for life, Golf GPS unit, professional DJ and audio equipment, etc. And it's always only a few dollars each time...unless there is a 50% discount every day, then this is really a bargain! ;-)

The same goes for animal shelters and garage/tag/yard sales...

Better communities have better picking.

But the video recorder is electronic! This article is about VCR.

I really don't understand why these e-waste recycling stations do not allow recycling. You think you can make a lot of money by offering the option of "$x per pound" (obviously the asking price is much higher than the price they get themselves), with the terms of no refund, no replacement, and no complaint More importantly, use the no-harddrives clause to facilitate data security considerations.

Lachute used to have an electronic product recycling/processing center, where guests could dig through their trash cans and pay a nominal fee for the salvaged items. For those who prefer electronic trash can diving, This is a magical wonderland.

I came across all kinds of products from full-size old line printers to broken avionics to every old and varied computer component. It is convenient to repair and find the hardware of EISA, MCA or PCI-X machines.

Sorry, they have terminated this service.

Because they are often searched by people looking for broken computers, and then pretend to be charitable organizations selling refurbished electronic products for African school children. They get money from real charitable organizations, put them in containers with broken computers, and then disappear again.

Our local e-consulting company comes to the office to pick up the goods. There is a warehouse there. If you want, you can pick up the song server here. The last time I went there, I bought 2 HP servers with 32 cores and 72GB RAM for $100. But don't count on disk drives.

A few years ago, I got a small cabinet with small drawers filled with Goodwill's old wirewound resistors. Sometimes it happens.

I'm stuffed

During college, boys liked to pick up rubbish on campus. I have bought a good variable autotransformer since the 1950s. I just need to replace it with a new fuse and do some cleaning (I also upgraded it with a grounded socket). I learned how to drive ordinary LCD glass displays. I got some Swiss NEMA 23 stepper machines and need to turn them into some kind of CNC machine tools. A netbook with dead battery and no RAM cover. I use it to run some home automation equipment. Need to repair PCB centrifuge. Waffle machine (!) That is a gold mine.

My previous college had a place on the loading station where students (mechanical, electronic and other aspects) could take over things.

That's the source of my 13-inch south bending lathe.

Next time the microwave oven needs to replace the door switch (I have replaced the bottom switch twice), I want to remember GW.

The high temperature hot air gun and pliers can quickly remove the components from the board.

This one. Add a metal biscuit board/cake pan to fix and catch the fallen parts. Some passive containers are collected through through holes and SMD.

A small pair of vices or surgical clips will grab and add enough mass to most through-hole drills, and you can use a heat gun to focus on the solder side. Once the solder is sufficiently melted, the part will be pulled out/dropped.

By clamping the PC board vertically and using a small butane torch with a flame diffuser on the back, I have had some success in removing large or multi-pin through-hole parts. Normally, I can loosen and remove the parts without scorching the circuit board, but what if I do?

The final method of removing PCB is wet soldering technique. It is much better than using dry heat. I have an electric soldering pan, but it is expensive. I saw a videotape on YouTube with a video of a Chinese man. He has a dish-shaped metal plate on his body and a gas burner underneath with some molten solder in it. To me, his device looks very economical. However, when you heat the boards like indoors, it is not really a suitable place. As you have already pointed out, it is easy to scorch the board and smoke. As far as the splint is concerned, I hold the plate with a pair of pump pliers. They can be held well and keep my hands sticking out of molten solder. Then use your other hand or needle-nose pliers or needle-nose pliers to pull the part from the board. I can pull out the parts as soon as possible. The real time-consuming aspect of all this is that I put together piles of parts. It may take me 3 days to sort all the parts pulled out in an hour. I haven't found a way to speed up work. Although using an AVR transistor tester will help.

The solder pot sounds great. It sounds like something a hacker space can have if it doesn't cause a dream of responsibility night.

For me, I don't save everything on the PC board. Just components that I might reuse. I almost never save surface mount parts (unless they are rare) because my eyeballs are stubbornly set as through holes. In addition, when removing parts, I usually do not test parts; I store salvaged parts separately from "good" parts and test them when they are in use. Save a lot of time; -) Of the repairable semiconductors I have tested, I found that more than 95% are OK.

I also used a butane torch-but never left a PCB of toast :-) Therefore, a heat gun is much better.

So I heard it. When I tried it, my house was burnt and smelled bad.

If your name is "Shrek", I don't think you will smell bad smells in your house.

Do not use a heat gun to heat the components, but only the solder side:-) At least for the through-hole filler.

I clamp the board in a vise, then grab the component (if THT), gently pull and heat the back. Set the heat gun to 360 to 400°C instead of blowing to 600°C

Yes, at Goodwill, the power supply is usually only one or two dollars, but this is a bit like a handbag.

The best ones are products that are "UL certified", and the blanks of these products are marked with fuses and the like.

I only recommend goodwill based on the fact that it is a profit-oriented company. The money they earn from sales will not be used to help those in need. Their only claim is that they provide work for the community. Please make changes to your article in the hope that the author agrees that "good faith" is false. The Salvation Army and UN-Habitat are the best places for you to purchase hardware, because the proceeds they get from the purchase are directly used to help those in need.

The whole purpose of goodwill is to provide jobs for people who would not otherwise be unemployed. That is the service they provide. This is not fake, it is not about a charity like the Salvation Army. Each of them has a purpose and helps people in different ways.

+1

The Salvation Army is a bunch of hypocritical homosexuals. If you support them, you may also support Roy Moore.

Shopping in a for-profit store is better than building a store financially for religion IMHO

GA!

In my experience, the Salvation Army provides critically needed services to the poorest and poorest people in the community, and they do so without considering the religious beliefs or sexual orientation of the needy. Except for praying before meals or holding a service for anyone who wants to attend, they did not impose religious restrictions on anyone's throat. They are also quite effective. Most of the donations are used for actual services.

As far as "Christians" are concerned, the Salvation Army is as far as possible from Roy Moore.

I am not religious, but I am happy to donate money to support the Salvation Army. Before we finally agree that we all share the responsibility to help and support the poorest of us, we need groups like them.

/ derail

"Except for praying before a meal or holding a service for anyone who wants to attend, they did not impose religious restraints on anyone's throat.

At least "pray before meals", "to inculcate religion toward religion." I mean: "Why do entities pray?"-I don't believe in God.

However, when I want to get something religious or charitable, I don't have to worry the least. I buy where there are and/or cheap

If you were having dinner at a friend’s house and they happened to say grace, would you rush off the table? control.

Why does your purchase have a good purpose? Don't get me wrong, it's cool if you can. In the same community, if a thrift store is both a charity and a for-profit store, then I would choose a charity first. But if they are not a charity, why do they have some kind of error? They act as a bridge between the things to get rid of and the people who need or want them. What's the problem with them getting paid for this?

Besides...Isolating the landfill for a while is a good reason in itself!

Yes, I am enough for me.

So, because the name is "good", will this money go to people in need? Literally, isn't it? I don’t want every dollar I buy to go to Colonel Sanders’ retirement fund every time I buy a bucket of chicken.

Jean Luc Picard doesn't know how to tell you, but if we stop shopping in every store where we want to make a profit, there won't be much. Instead of taking anything from companies that want to help people in need, the decision to only spend money on this is actually absurd (and unsustainable) for us.

Who doesn't have 1000uF capacitors scattered around? Only in 0.1uF decoupling capacitors, I may have so many.

I will win "Tom" for $200.

"Let it snow!"

S. Connery

Ah, so you and I follow exactly the same path. Indeed, I might think of twelve such ranges in a convenient box, and there are more on PCBs elsewhere. As I have already said, I now find that saving time on both ends only requires leaving the parts on the PCB. Scan the board faster to find what you need without having to conduct more desoldering sessions to reduce the number of boards. I just divide it into a few major categories: current logic boards, analog boards and power boards. Put the complete power supply into another box. I have a few large boxes full of wires, connectors and harnesses, and they are endless.

I think it depends on the brand, but cheap consumer electronics will be the hardest place to get parts, especially electrolytic materials. You are not after high-quality consumer-oriented computer equipment.

It took less than 2 minutes and I had 1000 uF in my hand (but what is the working voltage?) Every electronic hobbyist needs a decent garbage dump. Mine is 1000 uF 10v Japan Chemical Exhibition. For some reason, I have a lot of 2200 and 1000, which are rare. This is another 1000 UF 25 volt Computamite that looks like a fossil. Ah, this is another...

In order to avoid becoming a pathological ard collector, I had to do some training on what I kept. My current rule is that if I grab something (roadside/trash can), it must be useful immediately (perhaps after a minor repair), otherwise I must rescue the parts as soon as possible, so I not only have to store broken equipment. Fortunately, I found this kind of disassembly is very therapeutic. It is much easier to store 4 sorted parts in a container than all broken equipment.

This... Once I have a bunch of broken motherboards, they can easily occupy a space of 1000mm×1000m×400mm. (Some are old servers with full ATX motherboards...PII era.)

I went crazy with the heat gun, but only hit the spots on the PCB until the circuit board blistered and the parts dropped (many are SMD). These parts are now placed in a small plastic box covering an area of ​​about 400mm×300mm×100mm.

On the other hand, there are some things worth going together. Those switching power supply technologies, if you need one, can be obtained by using the entire tool. If any radio parts are used, IC or peripheral parts can be used. In addition, the original circuit provides IC pinout or other detailed information. Not for all, but sometimes.

Michael

Yes, I tested it with 10 100uF capacitors. If this is a real desert island, it's ok. But I tried to make the final result a little more professional.

Well, anyway, the old parts taken out of the VCR are like "professional" parts.

The price of 1,000uF is very cheap and can only be purchased on spot. It may also be electrolytic, which means salvage or even old and new parts are suspicious. Welding a bunch of small "decoupling" capacitors in series sounds great, but there will be parasitic inductances that may prevent it from working as required.

I mean parallel. Need more caffeine!

Parasitic inductance will be reduced by connecting capacitors in parallel.

I must have a capacitor of more than 1000µF. For example, it is 40 * 10000µF on a thick PCB or supercapacitor with a 2-digit F value. But I don’t have 10000 0,1µF :-)

A few years ago, I encountered this problem and solved it. What I did was to try to create capacitors of various sizes and voltages, which could be used as universal substitutes. The physical size of the capacitor is my biggest concern. Usually I find out if I need to replace something like 100uF@16V, and trying to squeeze the voltage of 100uF@25V in is very difficult. Therefore, use extra long leads or move some Things are very difficult. is compulsory. I even found the following situation: In terms of size, accurate capacitance and rated voltage substitutes are not a drop in substitutes.

In general, I will try my best to maintain various suitable voltage values. This accounts for about 50% of my repairs.

Another good source of information, if you have one locally and can be responsible for it through @ssholes, it is a garbage dump or recycling center.

People often discard old electronic products, especially old TVs. They are not wrong, everyone now only wants a flat screen. Moving the PCB out and discarding the rest can take up less space. Let the @ssholes running these places let you own them, which is another matter. Once, I can get them for free, or pay that guy a few dollars to let me own it.

I used to get flat-screen TVs from the garbage dump, repair them or use the parts in them. Now, I can't even sacrifice a goddamn goat for the goddamn @ssholes, or even get a goddamn cable.

It is also a good place to buy parts for washing machines and dryers. These controls and elements are not cheap when they need to be replaced.

Because my father-in-law works in one of these places, it really has something to do with me personally, and I have repeatedly pleaded with him why they should protect the garbage.

He can bring a rusty bicycle to my house to repair the kid for me (yes, yes...), but no, I can't break the law, break the rules and reject any of these TVs!

"What law?"

…………….

Needless to say, when he needs repairs now, I will bring him an old phone book with me.

Last time, when I put down some old electrical equipment, I saw a bunch of cables and grabbed them. In my area, I have seen them use people who have to perform community service as help. When a dumb and stupid fool is unwilling to show up next week, he will feel terrible and accuse you of being a thief. The cable was thrown away by others, and then after 5 minutes I saw the big truck being pulled up, grabbed the box, tilted it, and at the same time lifted it into the air, seeing everything inside sliding/colliding/cracking... …

I digress...

Anyway, I mean, if you happen to own one of these places locally, it might be worth a look to see if there is a place for electronic devices, how easy it is to access, or in the worst case, It's actually trying to be friends with someone or slip a few dollars to them to use it. They can't make enough money to brag, and depending on what you can get, the money thrown away will indeed last.

Yes, now my neighbor and I have been warned several times at the dump, don’t pick it up when we get off the car ;-)

There are several chain stores here, and their parking lots have open trash bins for customers to recycle. If I take out something, no one will open my eyes, so I can still check it occasionally.

Things that people will admire: wall warts and power supplies, IEC power cords, perfect USB cables...

Yes. Even fifteen years later, I have gotten interesting things in the sales of refurbished machines. The HP4P laser printer, which I have hardly used, sold for $15 at the garage auction of the local Rotary Club. But many of these sales have ceased. Electronic devices have become more and more common. If electronic devices do not work properly, they cannot make money from most people. However, checking electronic devices usually requires skills, and among volunteers, such skills may be lacking. I suspect that people complain about broken electronic devices in places like this because they don't know what to do.

Therefore, "waste recycling" got it. I see fewer electronic devices on the sidewalks, so people are learning to "dispose of them properly." But as you said, it is not limited to damaged items. They just want it, or they think it is "obsolete". Before, it had a second chance of life, but it has not happened yet. Therefore, it may be a collector’s item, or something esoteric (I bought a Grundig Satellit 700 portable shortwave radio, which is the best of the new products. It was sold at the Rotary Club auction in 2007 for $2.50 It is sold at a price, no one really knows what it is), or to keep the old computer running, or something that people without money can still appreciate (many digital cameras without megapixels at all).

I am worried that they will not be given a second life except for the obvious items (iPad and the latest computers). The value lies in gold and everything it provides. People may also use it for recycling, because they will not see its secondary use, some are too picky, they don't want others to get their things for free. A few years ago, some people speculated that this is a real business and they like to recycle. If I can't buy a second-hand GPS for five to ten dollars, then I must pay in full. I certainly want to know why some food establishments offer free items if you bring a MO3 player or something more valuable than pizza.

It would be great if the public had the opportunity to take what they wanted before being dragged away. When there is a collection, I want to stand, hoping to intercept things, but I may be eliminated. This system is suitable for ordinary people, not only the worn-out items they have not used, but also when it does not work, you may bring it back to the waste liquid system.

I was lucky to get to the right place at the right time when several electronics stores closed, so I got ICs, transistors, TV parts, etc. for almost life. Regarding capacitors, chips or expensive transistors, I can only get online services provided by their reputable suppliers, or NOS provided by remaining shops: cheap Chinese sold online are rubbish, and all IC/bjt have fake labels . Don't expect to buy thousands of 2N3055 (power BJT), 2SC1969 (a well-known spare part of CB radio) or NE5532 (low noise operational amplifier for audio) on Ebay/Aliexpress, and hope to buy only one genuine one. Chinese resistors and inductors are usually okay, and the materials (thin wires) are cheaper, but they usually work and are accurate.

When I was a child, I carefully copied the parts list on a piece of paper for my first few projects, and then went to the store I found in the yellow pages. It's a bit expensive, I almost know I have no choice. They did not work. Some of the reasons are my lack of soldering skills (this is a wood-burning soldering iron), but I don’t know if the replacement parts are suitable or if the pin arrangement is different.

Things started to work when I started to disassemble the parts, including the 99cent plank used by the local store to drive the Nixie tube. Twisting the very short leads together ensured that the problem was not my lack of soldering skills.

But it means that I have improved and learned enough to streamline parts and save money. So I always do this.

For a period of time 20 years ago, I found an early mobile phone for a few dollars, which contained interesting RF components, but the integration was low, so the familiar ICs (such as NE570 compressor and CPU) are mainly Through hole parts. I will carry some tools with me so that I can grab specific parts when needed. Power transformers can be expensive, but variable capacitors are few, so sometimes it's worth just pulling those.

About ten years ago, I had an "early" Powerbook. It didn't have a power adapter. It needed 24VDC. I remember that printers usually have a higher voltage, and the first inkjet I turned on had the required voltage and was on a separate component.

We have lost some windows. The use of variable capacitors can reduce the number of radios. Most power supplies are switching, so it is easy to find a power supply, but there are fewer transformers used to make linear power supplies. The clumsy cell phone has dried up. I rarely see TVs with analog tuners, and I rarely have a chance to find RF MOSFETs with leads.

Express mail order is a relatively new thing, and of course there are not many places in Canada to deal with hobbyists. Assembling parts is not only a way to save money, but also a way to source locally. In addition, it forces you to know the parts, what is needed and will work. When I can take a part and say yes, it really dazzles the high school kids.

But I have been thinking about the cousins ​​of my distant relatives, who have never met in the Colville Reservation in Washington State. I have never been poor, but never have enough money to buy books and hobbies. But I can always find second-hand books and parts because I live in a big city where there are many books. In more rural areas, especially if people without money can easily throw things away, I won’t be able to get them. Imagine those smart kids who cannot pursue things because they have no money and no chance to touch the rubbish in our city. This can be a real burden. Their limitation is not wisdom, but lack of resources.

Yes, everyone joked about Radio Shack until they were gone.

Where is your God now?

Our last electronics supply store is about to close. I did a mathematical calculation of the time required to buy and stay open. Very sad.

I'd better burn the money.

I have never joked about Radio Shack. I do complain that too many of them have become computer and phone shops, but there used to be a good selection of parts near me, from resistors to Arduinos. Of course gone. Delat

At the radio repair site, there are some trails that slowly stabilize those old catalysts. It should be clear at a glance so you know how to back them up. They said that as long as they slowly return to their original condition, most old bottle caps can work normally.

When I lose a storage point, I have to get rid of many parts. Finished the work of opening the case, pulling the power supply, battery holder and connecting cable, most of the rest was cast.

You cannot "stabilize" dry and/or expanded electrolysis. In switching power supplies, you must also consider low ESR capacitors. The standard will not last long.

I took time to get rid of the parts my father collected. Thousands of vacuum tubes are the least valuable, but some sell for more than $100 on eBay. When I touch resistors and capacitors, they are messed up.

shame. Look at what the old man Blasbla is doing.

A widow in the church said that next time I pass by, she will let me have the late husband’s TV vacuum tube and (vacuum tube) testing equipment. I am afraid that if I accept her proposal, my wife will be the next widow.

I extend my condolences to your wife. By the way, can I give you TV tube and TV tube test equipment? ????

Hit your wife with a plan: any working test equipment will become a goalkeeper, you will repair, strip or recycle things that are not working in a short time, and you will pick test tubes and then rest in ebay/hamfest/recycling.

When my wealthy uncle died 2 years ago, my aunt reduced the size and they provided me with his first choice of high-end stereo equipment. ReVox, Thorens, Altec-Laning...

I live in the Chicago Land area and there are many goodwill shops nearby...

My hot tip is to shop in affluent communities, trust me, electronics outside Wheaton or Naperville are cheaper than other areas.

Anyway, my experience...

later

My experience is just right! Except in another state. ????

You must be very careful when using old electrolytic capacitors. I haven't seen it yet, but a list must be made somewhere to show the mean time to failure of different electrical components and their shelf life. Depending on the materials used to construct them and their source, some obviously have a life span of several orders of magnitude longer than others.

But he was able to complete this project. He can take notes, so he knows that this is a reused electrolytic material. Of course, if the problem is the electrolysis treatment of the switching power supply and the high frequency on the numeral board, 60Hz will not have much effect on electrolysis.

The life of electrolytic capacitors depends on the quality, which is 1,000-20,000 hours. To make the old electrolytic capacitor put back into use after a long time, you must perform a process called "deformation". This is slowly increasing the current through the capacitor to rebuild the oxide layer on the foil. I have retrofitted decades of old capacitors and restored them to usable specifications. But I do live in a quite humid place on the earth. What I want to say is that the best old-fashioned capacitors will be made in Japan. I think all the western shots have been shot today. Rubycons is the best. I have seen Ruby over 40 years old still work. But recently I did have to throw away an old Ruby. It is being read as a resistor. So it disappeared. Needless to say, you should test any old parts that will be used in the new circuit.

I live in the darkest Africa, a 3-hour drive from the nearest town. I have a storage room called "Archives", where I store all the old garbage that may be useful. Minimize peeling as much as possible. For example, the computer power supply peels off the circuit board and packs it in a box with a fan. Space is a precious commodity. Conduct an annual assessment and throw things away. This will also help you keep informed about what you have and draw some good ideas from it. I love a good electronics store, it is hard to find nowadays, but always looking for it. Recently in London, I suddenly jumped into the Maplin I was passing by and found capacitors in blister packs, resistors of various values ​​and some RF adapters. involuntarily.

Because I am the only electronics person in the area, this may be a lonely business, but it does serve the local community.

Fun rather than profit. When you talk about the fun of repairing an inverter welding machine or how to use an old satellite dish to hack into 2 kilometers of unsecured wifi, how people open their eyes is very interesting. Today, poor electronics and software coding don't seem so cool.

Oh no, this is still cool.

I bet that HaD might be interested in an article about hacking in Africa, the darkest, and to what extent technology has affected the world.

When I pull out the parts, I only need to pull the Weller gun out of the holster. After a few seconds, the parts will be free. I can't see how people without guns (no NRA approval) live. Have you ever tried to return the middle pin connected to the housing on the regulator, and the regulator has been installed on the radiator with a pencil sharpener? I have seen so many self-desoldering voltage stabilizers on the board crashing, and their temperature is not high enough to cause a wave.

My favorite second-hand goods are the St. Vincent department store, where you can't buy things that are not good enough for high-end stores. The price of the DVD player and VCR is $5. Tons of other things have appeared, and you can get everything at a uniform price-usually under $10.

I repair old stereo equipment and arcade machines, so almost every repair requires fresh electrolyte. During maintenance, I will not use the remedial electrolytic cover. I hope my repair work can outweigh my regrets. The use of 20-year-old thermal stress components from unknown manufacturers is the source of the disaster. If you can't focus on the item of parts shipment for a long time, you should consult your doctor about Adderall (tm).

As for the story of my repair parts-how about this cute turntable using a control switch snatched from a hair dryer?

But the audiophile in me said that these switches will bring a fuzzy sound to your recording.

Not "fuzzy". "Warm" voice.

If you use capacitors, has anyone tried replacing XC capacitors? They are AB-619 units of 16 units in the electronics department.

They are rated at 33,000 volts and have no leakage.

Send the teletypewriter to Pete Knowles of Supreme Equipment, where it will be processed. Free shipping and zero invoices!

If you really like adventure, please try Interociter Kit. Or build a project that meets the needs of every housewife, an interactive device integrated with an electronic sorter!

!

That kind of cultural reference is directed at me!

I have someone made fun of me for saving what I did. These people often come to me.

On another topic, this is a hot tip. Next time you tear something with a motor, take a look at the PCB near the motor connector. Under normal circumstances, you can use the tool of your choice to cut part of the circuit board, and you can use it at any time.

I remember arguing with people in the comments about the benefits of storing physical stores around. So many people seem to think that since we have cheap Internet goods and free shipping, this idea is outdated. Now, Rat Shack has finally disappeared, this is this article!

If you do have a shop with parts nearby... why try to get some parts there from time to time? When you are here, you can enjoy browsing and even chat with the owner. If we all do this, maybe we can actually have good things like e-shops again!

I will tell you... Shopping in the shopping mall Rat Shack is much more fun than watching my wife look at the clothes!

I refuse to subsidize physical stores. I believe that a free market economy is too reasonable to prove this situation. They either compete or die. This is why our system is superior. Our inefficient waste has decreased.

I have no objection to someone buying something from a thrift store to get a part. Hey... at least some of them escaped the landfill. But... throw everything away... find that you need a part... buy something from a thrift store just to get a part... and then write it down...

I hope to mention at least one idea, that is to throw everything away is wrong! Of course, it can be thinner from time to time, but please don't buy the entire device just to get a capacitor, this is daily work! What a waste!

You can buy another device later to provide capacitors for the nibbled device.

It's not really that wasteful. (No, he didn't throw away everything)

First of all, if the equipment is curbstone, recycle bin or trash can... it has already been disposed of. If it has a good reputation, then maybe it is still working and it is worth finding someone else. However, if it is damaged, dirty or incomplete, it may not be used again.

Secondly, when I took things apart, I finished the job: the plastic ended up in a pile, the metal ended up in a pile, and the PC board and wires were piled up again. You can bet that I usually pull out useful things such as hardware and power supplies. These sorted piles are then placed in the most suitable person or clothing, for example, the sorted metal is transferred to a metal recycling station. Therefore, I am performing part of the recycling process.

Finally, if I trouble repairs or plunder other people’s equipment, you can bet that I can also get more use opportunities from buying new products, and I will not throw away good things like most other people do.

If I pre-decompose/sort electronic products before putting them in the county recycle station, they will usually be exempt from the electronic waste surcharge. The circuit board goes directly to the trash can, and the metal goes to the trash can. I have to pay the standard fee for the remaining plastic.

"(No, he didn't throw away everything)"

–According to the article –

"By then, I would usually browse the junk electronic products and computer motherboards I collected, but recently I double-checked and threw away what I remember."

"If it is a kind of goodwill, maybe it is still working, and it's worth finding someone else." However, if it is damaged, dirty or incomplete, it may not be reused. "

–We have read the same article –

"The era of despair requires desperate measures, so I got in the car and drove to the only place I knew I could buy with cheap electronic components: goodwill."

"Therefore, I am performing part of the recycling process."

awesome! For the earth, recycling is usually better than landfilling and using new resources. But this is not perfect. Reuse is better than recycling.

Recycling materials involves transporting them to processing plants, then to factories, and finally back to warehouses, shops, and houses. Your recycled materials may have traveled 100 miles (if not 1,000 miles) before being put back into use. That is a lot of carbon. Moreover, large amounts of energy and/or chemicals are used in processes such as melting and purification. The smoke is released into the atmosphere.

It is almost always a better choice to just sell the goods to locals who plan to take them home and use them instead of recycling them into new things! The only exception is that compared with the newer design, the old product is really not energy efficient. However, to offset all the environmental costs of recycling, the efficiency is much lower.

Again... don't get me wrong. I don't want to be too picky. It's good to occasionally buy goods from thrift stores. In the end, they may not sell all of them. What I responded more to is that there seems to be some movement among "hackers/manufacturers/eaters or others" to stop keeping trash cans, throw away all the waste, and just buy everything. This is really wasteful and bad. This will be a positive way to reduce consumption, which is much more wasteful than always buying new and ready-made things like any other time!

"Throw away all waste"

Again-the guy in the feature article "don't" throw away all his scraps. He just didn't keep the hat he needed later. Follow the link.

No one here, including OP, tells you to stop saving parts and not to reuse/recycle gear responsibly. Quite the opposite.

I like to pick up items for reuse. Two years ago, I used something to build my combat robot. Parts include the wheels of the vacuum cleaner, the pulley of the cordless rig, the pulley of the tape recorder, the nails of the old printer (BTW's great motors, I find them very attractive), the old tent support frame, and even the ball bearings. Interestingly, I got a ball bearing from a large copier and a ball bearing from a children's scooter. They are exactly the same. In retrospect, I should not use the one on the scooter due to wear and tear. Still everything is normal. I was also lucky because I asked for permission to get something from the local introduction site and it was approved. As a result, I collected all kinds of printers, DVD players (I hope one day for the motor of a small drone) and their lasers, photocopiers, and even some music mixing devices with sliders (I I suspect that the electronic equipment is of good quality). Of course, as a beginner in electronic products, building a robot will involve many wrong turns and a lot of money. .But I don’t regret it, because actually building something is a wonderful experience that changes life. Feel free to ask if you need more detailed information about my robot. By the way, I like this website!

I am really surprised how long it will take to order online to ship to the United States. I should visit a friend in California (should be in the future), I need something, and finally I spent 3 days of "express" shipping! If you order before 7pm, you will not be able to carry out standard delivery in most places in the UK the next day (later on Amazon). Something will come that day! When my focus keeps shrinking, I need something...oh, squirrel!

I noticed that Maplin, a stockist in the streets and lanes of the United Kingdom, just renovated my local branch. They have eliminated the component counters and focused on cheap foot RC toys and other consumer waste that I can buy. Haven't tried to ask them for capacitors, I can last a few years now :)

Damn, damn you! Here, I thought at the time that my one-stop service for salvage supply would always meet my salvage needs, and when in order to access my diverse parts cache, my companion would have to go through the local garbage dump for hours. Now that the secret has been revealed, you have ruined it for everyone. thank you very much.

I removed the bulb from the desoldering iron and replaced it with a solder suction cup. It makes FAR a more effective tool.

A large number of parts can be found in Volunteer and Salvation Army stores in the United States. For example, the price of a vcr or am or fm radio is 3 or 4 dollars, which is stupid, you know it does not work. Goods priced at 19.95 will work normally, and there are other goods. They have excellent decomposable items, and you can add them to the inventory of the desired item by purchasing cheap components of many components.

I live within driving distance of SparkFun, and there is a lingering RadioShack about 15 minutes away. Although the power supply of RS is very dim. There is also a miniature center with some passive components.

I started using parts removed from old televisions and stereo equipment found in old appliances and trash bins (this is where you bought such items in the 70s). I built my first project using most of the removed parts. I used all the scavenging parts to make my first audio amplifier. Class A, a horizontal output transistor and a 10 ohm resistor, a large electrolytic capacitor isolates the speaker from DC. in a hurry.

I learned to look at the resistor color code because I have a box full of resistors. I was too impatient to sort them all and put them in labeled boxes or envelopes.

Surface mount parts are difficult to remove. I will still remove ferrite. I just gave a class at OlyMEGA, a local manufacturer's space, and explained how to use all the parts cleared by CFL to make a Joule Thief.

I have cleaned some 20uF ceramic capacitors. Surface mount, but easier to remove due to its size. Otherwise a bit expensive. I'm building something that requires very low ESR power to support high current pulses, so some of the array and some low ESR electrolyte will flow to the PCB near the component. One is to test the saturation flux of the ferrite core. The power supply must not sag, otherwise the reading will be damaged.

If the part is to be sold, all new parts will be used.

Blarsblarson, I am very interested in the removed parts and hardware (because I belong to an antique radio/electronics club and we are always looking for parts, even TV tubes; there are several winemakers among us ) Willing to pay Phoenix-Bruce Thorpe N7MMR

This is great. I really like your equipment. How many do you have?

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If you build electronic circuits on a regular basis, you may use capacitors multiple times. They are standard components used with resistors, and their resistance values ​​can be proposed without consideration. We use them for power smoothing and decoupling, DC blocking, timing circuits and more applications.

The capacitor is not a simple spot, it has two wires and two parameters: working voltage and capacitance. Various capacitor technologies and materials have different characteristics. Although almost any capacitor with the correct value can accomplish the task in most cases, you will find that understanding these different devices can help you do things that not only accomplish the task, but also do the best. For example, if you have to pursue thermal stability issues or find these additional dB noise sources, you would be very grateful.

It is best to start with the basics and describe the capacitance from the basic principles before studying the actual capacitor. The ideal capacitor consists of two conductive plates separated by a non-conductive dielectric. Charge will accumulate on the board, but due to the insulating properties of the dielectric, they cannot flow between them. Therefore, the capacitor can store charge.

Capacitance is in farads: a farad capacitor holds a voltage of one volt while holding a coulomb charge. A farad, like many SI units, is impractical in size, so outside the narrow domain of supercapacitors (outside the scope of this article), you are more likely to encounter micro, nano, or picofarads. You can use a formula that may be worthwhile to derive its capacitance from the size and dielectric properties of any given capacitor

. Unless you are studying for a high school physics exam, you don’t need to remember it, but it hides an important point. The capacitance is proportional to the dielectric constant

The increase in the number of dielectric materials used has led to various commercially available capacitors using different dielectric materials to achieve a higher capacitance range or better voltage handling characteristics.

There are obstacles to the use of dielectric materials in capacitors, and the ideal properties of dielectrics also bring many unpleasant side effects. All capacitors in the real world have internal parasitic resistance and inductance. Although small, they sometimes affect the operation of the capacitor. The dielectric constant changes with temperature or voltage, piezoelectricity or noise. Different types of capacitors may have shocking failure modes, and even amazing prices. Therefore, we have entered the main part of this section. In this section, we will take you to understand some types of capacitors you may encounter and list their various characteristics, including good and bad. We will not claim to cover all possible capacitor technologies, but we will introduce common capacitor technologies and check any subtypes you might find.

An aluminum electrolytic capacitor uses an anodic oxide layer on an aluminum plate as a dielectric, and the electrochemical battery electrolyte that forms it is used as another aluminum electrolytic capacitor. Because they are electrochemical cells, they are polarized, in other words, any DC potential passing through them must always be in the same direction as the anode plate (!) or the positive terminal as the anodized plate.

The pole plates of practical electrolytic capacitors in the form of aluminum foil sandwich plates are rolled into a cylinder and contained in an aluminum can. Their quoted working voltage depends on the depth of the anodized layer.

Electrolytic capacitors have the largest capacitance you will encounter in normal use, ranging from 0.1 to thousands of µF. Due to the tightly wound electrochemical cells, they have a high equivalent series inductance, so they are not suitable for use at high frequencies. In general, you will find them useful for power smoothing and decoupling and audio coupling.

Tantalum electrolytic capacitors are in the form of sintered tantalum anodes, which have a very high surface area, on which a thick oxide layer is grown, and a manganese dioxide electrolyte is applied on it as the cathode. The combination of high surface area and the dielectric properties of tantalum oxide dielectric means that the capacitance per unit volume of tantalum capacitors is very high, so tantalum capacitors are much smaller than aluminum electrolytic capacitors with the same capacitance. Like aluminum electrolysis, tantalum capacitors must also be polarized, and the DC potential at both ends must always be in the same direction.

The value of tantalum capacitor is about 0.1 to hundreds of µF. Compared with similar aluminum products, their leakage resistance and equivalent series resistance are much lower, so you can find them in test and measurement, high-end audio, and other advantageous applications.

Tantalum capacitors have a failure mode that requires attention. They are known to catch fire. Amorphous tantalum oxide is a good dielectric, while the crystalline form of tantalum oxide is a good conductor. Misoperation of tantalum capacitors by applying excessive surge currents to tantalum capacitors may cause the dielectric to change from one form to another, resulting in a substantial increase in the current flowing through the capacitor. Fortunately, not all news is bad news. Their reputation in the fire comes from earlier tantalum capacitors, and improved manufacturing technology has delivered more reliable products.

There are entire series of capacitors that use polymer films as dielectrics, which are sandwiched between coiled or staggered layers of metal foil, or have a metalized layer deposited on the surface. The rated voltage of these capacitors can be around 1000V, but they are not suitable for large-capacity capacitors. You will find that their capacitance ranges from about 100pF to single-amplitude µF. Each different polymer dielectric used has its own advantages and disadvantages, but the equivalent series capacitance and inductance of the entire capacitor series are lower than the electrolytic capacitors discussed so far. Therefore, you will see their use in higher frequency applications, as well as power supply decoupling in electrical noise environments and general applications.

Capacitors are used in circuits that require good temperature and frequency stability. You will also find that they are used in power supply suppression and other power circuits, especially for rated versions for high-voltage AC use.

Capacitors do not have the temperature and frequency characteristics of polypropylene, but they are inexpensive and can withstand the high temperatures of SMD soldering. Therefore, you will find them used as general purpose capacitors in non-critical applications.

Capacitors still do not have stable temperature and frequency characteristics, but they can withstand much higher temperature and voltage than polyester.

The capacitor has all the temperature and frequency stability of polypropylene and can withstand high temperatures.

You may also encounter

with

Capacitors in old equipment, but these two dielectrics are not commonly used today.

Ceramic capacitors have a long history, and you can find them in devices that span decades from today to the beginning of the last century. Earlier ceramic capacitors were single-layer ceramics plated with metal on either side, while recent examples also include multi-layer designs in which alternating layers of metal and ceramic are constructed to form a set of staggered plates. Depending on the dielectric used, the capacitance ranges from 1pf to tens of µF, and the voltage is kilovolts. You will find single-layer ceramic discs and multilayer ceramic surface mount packages used in a variety of small capacitor applications in all areas of electronic products.

When looking at ceramic capacitors, it is best to consider them in terms of the ceramic dielectric used, because they derive their performance from these capacitors. Ceramic dielectric classification

It is these codes where we will quote the most common codes.

The dielectric has the best capacitance stability in terms of temperature, frequency and voltage. You will find C0G capacitors for resonant high frequency and other high performance circuits.

The dielectric does not have the temperature or voltage characteristics of COG, so it can be used in less important applications. Generally, you will find them for decoupling and general-purpose applications.

The dielectric has a higher capacitance than X7R, but has poor temperature characteristics and a lower maximum voltage. Like X7R, you will find them in general purpose and decoupling circuits.

Since ceramics are also generally piezoelectric, some ceramic capacitors also exhibit micro-sounding. If you are working under high voltage and audible frequencies, such as in a tube amplifier or electrostatic environment, you may sometimes hear this effect because the capacitor may "sing". If you use piezoelectric capacitors to provide frequency stability, you may find that they are modulated by environmental vibrations.

As mentioned earlier, this article does not attempt to cover all capacitor technologies. A quick look at the electronic consumables catalog will show you several technologies not mentioned here, and many others are outdated or have a small niche that you rarely see them. Instead, what we want to achieve is to make some of the common types you might see mysterious and help you make choices when you make your own designs. If we arouse your appetite for more component loss, maybe we can get your attention

.

It doesn't matter, use capacitors that require almost zero inductance in the microwave area.

How about im head capacitors?

Or PCB capacitor?

Variable PCB capacitors?

Yeah, I know. "This article does not attempt to cover all capacitor technologies." I just want to point out that those will be interesting because you can make your own!

Lol, no, they are useful links, not sure if his book lists other uses for large capacitors...

Thank you for linking with variable PCB capacitors. This will come in handy.

I like those links. thanks for sharing.

No mention of the capacitor disaster:

Jenny forgot to mention that Magic Blue Smoke was among them.

No, that's fast magic blue smoke. It escapes faster than ordinary blue smoke.

Thank you for your information! Don't know at all (always think what I see is related to the wrong temperature specification)​​!

Particularly worth reading is the root cause of this huge problem: the perfect example of "good, bad, ugly"-capacitor companies in Japan, China, and Taiwan. Maybe this is the reason why my 2006 iMac power unit failed.

charming! I know this question, but I don't know where there is such a comprehensive understanding. Thank you for contacting us.

The trap for young players is the forced pressure reduction of tantalum... The issue is not often mentioned until the part fails and the manufacturer points you to the white paper.

Other curious traps:

– The capacitance of ceramic capacitors varies greatly with the applied voltage. If a voltage close to 10V is applied, a 100nF rated 10V capacitor may only have a 10nF capacitor.

– Class 2 (not COG NPO) ceramic capacitors decline over time and recover after re-soldering. This is a non-linear thing, which is very eye-catching for newly produced or newly welded caps.

– When a new aluminum electrolytic cover or no voltage is applied for about 6 months, the leakage of the aluminum electrolytic cover is 10 times. They need a few minutes to "reform".

– The leakage of aluminum electrolytic capacitors varies with voltage in a non-linear manner, so general electrolytic capacitors usually self-discharge to about 30% of the rated voltage quickly, and then will not drop below 20% of the rated voltage for months or even years.

-The aluminum electrolytic cover will change proportionally with temperature, and all other factors will change slightly. A good rule of thumb is that for every 10°C increase in operating temperature, it will decrease by half an hour. vice versa. So, if you run 1000 hours at 100C rated capacity at 40C, it will last 64,000 hours.

–Specifies the capacitance value of Class 2 (X7R, Y5U) ceramic capacitors and the tolerance at +25°C. In most cases, the peak is not far away (maybe 20°C). This means that when you stay away from room temperature, the capacitance usually drops. It does not increase one method, nor does it reduce another.

Regarding the first point of the list, the change in capacitance with voltage is only applicable to Type 2 dielectrics. It also particularly affects smaller external dimensions, but does not change much with the rated voltage. This Maxim application note is very interesting:

The C0G/NP0 dielectric is basically flat. But this is something that many people will miss, because most of the ceramic capacitor datasheets I have seen don't even mention it, and there is no e-book I have read, nor is this article.

Same Here. I didn't fully realize the characteristics of DC bias until a few years ago, when a sales representative of a supplier who had just released a series of new bottle caps with "low DC bias function" came to our company to advertise. Makes me wonder what else is under the carpet.

How repeatable/reliable is the effect?

Can you reliably build a VCO by applying different bias voltages?

There are not only type 1 and type 2 ceramic capacitors. A better statement may be that the Class 1 capacitors were not significantly affected.

correct.

Then there are temperature-compensated ceramic capacitors. They are not common in today's cheap crystal oscillators and digital synthesis frequencies, but you will find them in older equipment, and perhaps in some older electronics stores. If you use them by mistake when you expect the temperature, you will feel unhappy. They are usually available in N750 and N1500, if memory is available, P150 and N2200 can also be used. They are used to stabilize the temperature of RF oscillators and filters. The inductance of the inductor will increase with the increase of temperature; therefore, the use of capacitors with a negative temperature coefficient (for N750 type capacitors, 750 parts per million degrees Celsius) will be used to maintain the resonance frequency roughly with temperature changes Constant. They will be used in parallel or in series with NP0 (C0G) capacitors to produce a net temperature coefficient that offsets the net temperature coefficient of the inductor. The use of temperature compensation capacitors can produce surprisingly stable and easy-to-tune tens of megahertz oscillators.

If you can find it, does ETI remember? John Lindsey Hood has written a series of wonderful articles called "True Ingredients." It thinks in the late 1980s. It's worth trying. I have a series somewhere.

John Linsley Hood

I cannot find many online copies.

Thanks for that. If there is enough interest, and I can sort out copywrite, I can scan my article. In 1985, memory was still OK. I know it will be there.

Please I am very interested. When reading in-depth articles about electronics in the 1980s, I got the golden age of electronic atmosphere.

There are copies of old 1950s popular mechanics everywhere on the Internet, and I really like the copies I have. The big business at the time was selling mail-order courses to train people to become TV technicians. The college competition provides more and more things to build themselves, with meters and complete TVs with various screen sizes.

I recently started as an electrical test engineer and started using "professional" parts. The main difference lies in designing and ordering parts for each project. Out of hobby, I picked up a box of old capacitors and pulled it out until there were (close to) matches. Anyway, in my project, I found 10uF (50V) ceramic capacitors in the 1206 case, and I used them to replace the electrolytic capacitors in circuits such as MAX232. In the case of 1206, they rose to 220uF (2,5V)...

That's great!

Now, understand the DC bias effect of each ceramic capacitor whose dielectric is not NP0/COG.

Pro Tip 1:

Your 10uF ceramic capacitor is not 10uF.

Although this is much more detailed than the article, please don't forget to use Mica capacitors to prototype the semiconductor buffer in the switching power supply.

Pro Tip 2:

If you work in engineering and want to keep that job, please visit the manufacturer's website to calculate the life of aluminum electrolytic capacitors in your application. This is especially important in power supply, high temperature, high rms ripple current or high voltage applications.

Pro Tip 2a: Press the ctrl key and click to display the root mean square value of the waveform in LTSpice.

Thanks for the tips. The capacitor rating is 1v DC. The size of the 1206 is better than the smaller size, which is the main reason why the 1206 is selected for low output and easy manual welding (expensive labor).

For me, the most important point mentioned earlier is the effect of temperature on the life expectancy of electrolytic capacitors. In my experience, due to other reasons beyond the rated value, the failure of electronic equipment is almost always caused by the failure of the electrolytic capacitor. If you want to continue using it for 10 years, it is best to keep any electrolyte cool. Keep them away from CPUs and similar chips, etc. Your device may be used for several years.

Don't forget that flux capacitors usually require very high voltages to work.

Rated working time is -30 years

Please don't believe it until you see the data sheet and receive a sample of my product from Rubycon.

I miss capacitors-they can actually condense electricity. Electrical condensate is indeed powerful. You don't want to get anything.

But what can capacitors do? Will they be capacitive? Will they promote capacitation? Do you want to use those words in the sentence?

Abandoning Alessandro, they have not been called condensers for 60 years.

I have been working on motorcycles in the late 1970s, and all service documents refer to condensers wired as required. This means that only 37 years ago, it was still a generic term (at least in this app).

Condenser is a general term in ignition systems and has long been obsolete in other applications. I am sure that the replacement part is still called a condenser.

In Romania, they still call it a "condenser". You can imagine the expressions of an ancient university teacher when students say "capacitor" after reading an English document.

Personally, as long as both sides of the conversation understand what is being said, I don't care how to call them.

In Dutch, the word capacitor is still "capacitor"

And in the French "condenser"

In the automotive industry, they are still called condensers.

I am 60 years old, does that mean I am no longer useful?

If you touch the terminals of the larger terminals, they may make you incapacitated.

The term capacitor was first used in the 1920s. The Navy seems to be an early adopter. The condenser gradually disappeared until it disappeared (almost) in the 1960s. Some people think that capacitors are closer to the resistors and inductors already used, but who knows.

When I was working for Tek in the late 1970s, they discovered that for a particular case size, never use the largest capacitor available. Always go to the next larger box. I can’t start telling you how many caps were removed and replaced with larger cases to improve reliability.

Likewise, not all electrolytic capacitors are the same. Replace a low ESR capacitor with an equivalent value, instead of a low ESR capacitor, you will see the inside of the capacitor.

Mica caps can also be used. See that the CM04 cover can be unsoldered from the RF breadboard. When they moved to CM06, they got warmer, but not hot enough to melt the solder.

For the same capacitance value, the next larger case size has a larger surface area.

Calculate the key value of electrolytic capacitor life.

Unless absolutely necessary, avoid using tantalum capacitors, and then try to check your supplier. The tan tantalite industry has become severely corrupt, causing catastrophic wars and human rights issues.

If we follow this policy globally, none of us will buy anything with rare earth magnets in it, because +90% of the market is controlled by a totalitarian regime with a very bad human rights record.

So, Peter, if there is a hard drive in the computer, please return the computer. Only buy SSD from now on? What about everything else with a compact motor equipped with rare earth magnets?

Yes, if you haven't solved the problem, then I hate an evil person more than a proud evil person. He implies that they are not evil, and everyone else is evil.

Look, when I read the review, I just saw someone trying to light up something, something most people don't know. He did not say "Don't use tantalum capacitors", "If you use them, it would be terrible." He just kindly asked, "Please avoid using tantalum capacitors." All other statements in his comment are statements of fact. You can still use whatever you want in your design. No one accuses you of being evil.

Maybe you just reacted to the previous discussion about tantalum that you participated in before, and the commenter was more demanding than Peter.

Lol, what a hot load. As I implied, hypocrisy.

These days, can you even buy phones that guarantee conflicts and free human rights violations?

no, you can not. Many people do know this, and most of the people in this group really don't care. I care, but boycotting does not stop this practice. The people involved just adapted without actually reducing the harm to the innocent.

If you have questions about the behavior of immoral people, please disband these people, because there is no other way to stop them. Boycott is a very blunt tool, which usually causes a lot of incidental economic losses, and even more innocent people. Bring harm.

Do you honestly believe that you are so wise that you can recommend any form of boycott and can predict the true result? Why not just ask people to donate to NGOs that help those in need to resist harm? Isn't this more destructive, or more sensible?

Sorry if you don't like my opinion, but at least I can prove it strongly!

Regarding the phone, there is currently a project, although I do not claim to own it. As you said, there is no way to guarantee that they will do what they say:

.

I think you are confused-I have never tried to talk about tantalum capacitors since the beginning. Please read my comment again. I just want to point out that Peter is not accusing you of evil. He did not ask for any moral requirements. Yes, he advises you not to use tantalum capacitors, because that is his belief. But does he think he is "better than you" just because he doesn't use tantalum capacitors? I do not think so. This is the point I want to make. Is it hard to believe that this might be ignorance? In this case, the reply you just gave me will be deeply valued by him.

Most of the arguments you put forward in this response sound good, and if you put them in the original comment, I won’t have any questions about it. There is no problem with my opinion. I just want to use "attack your emotional foundation". Yes, if you haven’t solved this problem, the only evil people I don’t like are evil people. He suggested that they are not evil, others Everyone is. "This is not the right choice. In general, your first comment is indeed...not good. Has it become so difficult online?

Like I said, how hot the air is, you can't verify any of them. In any case, what right do you have to regulate the Internet, and that is that, in the eyes of some people, arrogance is just as offensive as in my comments. It looks like you are a self-righteous hypocrite like "Peter". Even if you just don’t dare to question them, your thoughts about “good” always boil down to people who “fit your dogma”.

>Sorry if you don't like my opinion, but at least I can prove it strongly!

This is not your opinion, but your attitude towards the opinions of others.

I'm sorry, Dan. What you are doing is "If we can't fix all the problems at once, then make those who try to fix certain problems proud". I must stand by Peter and Droif. Always pay attention to the problem, choose some problems and try to solve them. Stay vigilant and don't try to solve it (others may try).

Engineers should work like this.

You can choose not to use them in your design.

Yes, you can do what you want to do according to your own design, but don't deceive yourself, because you may actually be hurting others. If you can use them in your design and save money, you can donate the difference in profits to charity (if you really care). Or do you think bad people are better at doing good than bad people? Take a moment to think carefully.

No, I will not.

However, whenever I do not choose a tantalum cap, I will be happy for your rant.

This is not a rant, just a tantrum!

what! Okay, thank you.

I made it. Usually, because they can be used as electronic igniters well.

Obviously, Kemet "guarantees" that the tantalum in its products is conflict-free.

They provided a report listing the sources of tantalum (and other minerals): China, the United States, Thailand, Germany, Kazakhstan, Austria, and Japan. This is required by the US Dodd-Frank Conflict Minerals Regulations-does anyone here know more about this/bell?

AVX and:

All your stuff comes from China,

All your things are contaminated. Cheer up and stop deceiving yourself. The market is like a water container. You take water from one part, but you still increase the demand for all other parts. There is also the fact that once they enter a huge resource base like China, you really cannot track the material. You just want to feel special.

Would have liked to hear more about self-healing polymer capacitors. As far as I know, they are usually used as X or Y filter components in mains voltage applications, but maybe there are other interesting applications where self-healing capacitors are used? How does self-repair work?

Good article, thank you!

Errata:

I think tantalum has a lower leakage than aluminum electrolyte and therefore has a higher leakage resistance.

A typo, not a complete error :) – Every different polymer dielectric used has its own characteristics, has its advantages and disadvantages, but compared to the electrolytic capacitors we discussed, the entire capacitor series has an equivalent series* *Capacitance** and inductance are both low. to date.

Ok

The real conflict with tantalum bottle caps is their failure mode.

Find the safe derating of tantalum capacitors. They are ridiculous because they cannot be used in all applications except for the most absolutely necessary applications (very low ESR and high capacitance).

Safety is the reason to avoid them.

If your voltage converter happens to be 500w, what capacitor would you use?

:)

Some good things about iequalscdvdt.com

"Although not all news is bad news, their reputation in the fire comes from earlier tantalum capacitors, and improved manufacturing technology has provided more reliable products."

Do not. You may be confused by the existence of multiple "tantalum" caps.

. The sturdy tantalum cover has a fire failure mode. This is not surprising: the electrolyte is MnO2, so you have many easy-to-access oxygen tanks, and they will flourish. However, the sturdy tantalum capacitor caps can also be self-repairing and can withstand less pressure, so under the right conditions, they are very reliable and can be stable for a long time (no service life). However, they are still not inherently safe. The sturdy tantalum caps will not burn because of short-term failure, but because they "ignite" and burn.

However, the tantalum polymer cap does not have an ignition failure mode because the electrolyte is not MnO2, but a polymer. They also have lower ESR, but lower long-term reliability (due to polymer degradation). However, they will not catch fire on their own. However, they do experience short-circuit faults, so they can still take out systems that are not limited by current.

Niobium oxide caps are basically solid tantalum caps without an ignition device (long-term stable), so you would consider them ideal-but they are also expensive and uncommon.

For young players, the trap of solid polymer aluminum capacitors and electrolytic aluminum capacitors:

"Because the polymer is a solid, it also has a longer service life, and does not follow the classic Arrhenius formula. The temperature will not double every 10°C, and every 20°C drop in temperature, the life will be 10 times longer."

Translation: Every 20°C increase in temperature will shorten the life span by 10 times.

It's a bit different, isn't it?

A small mistake:

The equivalent series capacitance and inductance of the entire capacitor series are low

Should be "equivalent series

(ESR)"

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