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My Kingdom For A Capacitor | Hackaday

tagscapacitor resistance

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.


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.


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


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.


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...


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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