How to identify ceramic capacitors?-PINGSHANG

One type of capacitor withstand voltage label is a combination of a number and a letter. The number represents the power of 10 exponent, the letter represents the value, the unit is V (volt).

 Letter A B C D E F G H J K Z

Withstand voltage 1.0 1.25 1.6 2.0 2.5 3.15 4.0 5.0 6.3 8.0 9.0

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 E.g: 

1J stands for 6.3*10=63V

2G stands for 4.0*100=400V

3A represents 1.0*1000=1000V

1K represents 8.0*10=80V

The maximum number is 4, for example, 4Z represents 90000V. Generally, audio circuits include capacitors such as filtering, coupling, bypass, frequency division, etc. How to use various types of capacitors in the circuit more effectively has a greater impact on the improvement of audio quality.

1. Coupling capacitor

　　The capacity of the coupling capacitor is generally between 0.1μF and 1μF. It is better to use mica, acrylic, ceramic and other capacitors with less loss.

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2. Preamplifier, frequency divider, etc.

Capacitors used in preamplifiers, audio controllers, and frequency dividers have a capacity between 100pF and 0.1μF, while the speaker frequency division LC network generally uses a capacitor with a larger capacity between 1μF and several 10μF. At present, high-end frequency division CBB capacitors are mostly used in the device. Mica and styrene capacitors should be used when the capacity is small. The capacitors used in the LC network have a large capacity, and metallized plastic films or non-polar electrolytic capacitors should be used. Among them, inorganic electrolytic capacitors can obtain excellent sound quality if they are non-etched.

3. Filter capacitor

　　 After rectification, the capacitance of the capacitor used for filtering is relatively large, so electrolytic capacitors must be used. When the filter capacitor is used in a power amplifier, its value should be more than 10000μF, when used in a preamplifier, the capacity should be about 1000μF. When the power filter circuit is directly supplied to the amplifier to work, the larger its capacity, the better the sound quality. However, large-capacity capacitors will make resistance

The resistance starts to rise from around 10KHz. At this time, several small capacitors should be connected in parallel to form large capacitors. At the same time, several thin film capacitors should be connected in parallel to suppress the rise of high-frequency impedance, as shown in the figure below.

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Basic knowledge of capacitance

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1. The role and classification of capacitors

　　Electric capacity is composed of two metal poles with an insulating material (medium) sandwiched in between. Due to the different insulating materials, the types of capacitors formed are also different:

According to the structure, it can be divided into: fixed capacitor, variable capacitor, and fine-tuning capacitor.

According to the dielectric material, it can be divided into: gas dielectric capacitor, liquid dielectric capacitor, inorganic solid dielectric capacitor, organic solid dielectric capacitor, electrolytic capacitor.

According to polarity, it is divided into: polarized capacitor and non-polarized capacitor. The most common thing we see is electrolytic capacitors.

Capacitors have the function of cutting off direct current and passing alternating current in the circuit, so they are often used for inter-stage coupling, filtering, decoupling, bypassing and signal tuning. For more information, please visit the website https://www.electronic7.com/

Three, the unit of capacitance

The basic unit of capacitance is: F (farad), in addition to μF (microfarad), pF (picofarad), there is also a less used unit, that is: nF (), because the capacity of the capacitor F is very Large, so we generally see the unit of μF, nF, pF, not the unit of F. The specific conversion between them is as follows:

1F=1000000μF

1μF=1000nF=1000000pF

Four, the symbol of the capacitor

The symbol of the capacitor is also divided into the domestic standard notation and the international electronic notation, but the capacitor symbol is similar in the domestic and international representations. The only difference is that the polar capacitor is a horizontal line below an empty basket. , And the international one is that ordinary capacitors plus a "+" symbol to represent the positive electrode.

5. Withstand voltage of capacitor Unit: V (Volt)

　　Each capacitor has its withstand voltage value, which is one of the important parameters of the capacitor. The nominal withstand voltage of ordinary non-polar capacitors are: 63V, 100V, 160V, 250V, 400V, 600V, 1000V, etc. The withstand voltage of polar capacitors is relatively lower than that of non-polar capacitors. Said withstand voltage values are: 4V, 6.3V, 10V, 16V, 25V, 35V, 50V, 63V, 80V, 100V, 220V, 400V, etc.

Six, the type of capacitor

There are many types of capacitors, which can be divided in principle into non-polar variable capacitors, non-polar fixed capacitors, polarized capacitors, etc. From the material, they can be divided into: CBB capacitors (polyethylene), polyester capacitors, ceramic capacitors , Mica capacitors, monolithic capacitors, electrolytic capacitors, tantalum capacitors, etc. For detailed information, please visit the website https://www.electronic7.com/ The following table shows the advantages and disadvantages of various capacitors:

The advantages and disadvantages of various capacitors:

Polarity Name Production Advantages Disadvantages

Non-inductive CBB capacitor 2-layer polypropylene plastic and non-inductive, high-frequency characteristics are not suitable for large-capacity,

2 layers of metal foil alternately mixed, good, small volume, relatively high price

Then bundled up. Poor heat resistance.

No CBB capacitor 2 layers of polyethylene plastic and sensation, the others are the same as above? br /> 2 layers of metal foil alternately mixed

Then bundled up.

No ceramic chip capacitor Thin ceramic chip with metal film on both sides Small size, high pressure resistance, fragile! Low capacity

Made of silver. Low price, high frequency

(One is high frequency capacitor)

Mica-free capacitor Two layers of metal are plated on the mica sheet, which is easy to produce, the technology is large in volume, and the capacity is small.

Low film content, stable temperature (almost useless)

Good sex

No monolithic capacitors are smaller than CBB,

Others are the same as CBB, I have feelings

There are electrolytic capacitors, two pieces of aluminum tape and two layers of insulation, with large capacity. The high frequency characteristics are not good.

The membranes are stacked on top of each other, and then immersed in electrolyte (acid-containing synthetic solution) after being bundled.

Some tantalum capacitors use metal tantalum as the positive electrode, which has good stability, large capacity and high cost. (general

Spraying metal on the outside of the electrolyte has good high frequency characteristics. Used in key places)

As a negative electrode.

7. Nominal and identification method of capacitor

　　 Since the volume of the capacitor is larger than the resistance, the direct nominal method is generally used. If it is 10n, then it is 10nF, and 100p is 100pF. If it is 4n7, it is 4.7nF, and the direct representation without the unit: use 1 to 4 digits, that is, the index mark, the capacity unit is pF, such as monoliths and some ceramic capacitors, generally use the exponential form, 471 represents 47 ×10^1 pF=470pF.

Ceramic capacitors also have a direct identification capacity, and the unit is pF.

Tantalum capacitors generally indicate the value directly, and the common unit is N F.

(The capacitance digital identification part is supplemented by pongo netizens, thank you here!)

Color code representation: along the direction of the capacitor lead, use different colors to indicate different numbers. The first and second rings indicate the capacitance, and the third color indicates the number of zeros after the effective digit (in pF)

Color meaning: black=0, brown=1, red=2, orange=3, yellow=4, green=5, blue=6, purple=7, gray=8, white=9.

Capacitor identification: Look at the nominal value on it. Generally, the capacity and the positive and negative poles are marked. For example, on a tantalum capacitor, the end with a white wire is the positive pole. In addition, like an electrolytic capacitor, the length of the pin is used to distinguish the positive and negative pins. Positive, short foot is negative. For more information, please visit the website https://www.electronic7.com/

Resistance and capacitance sequence value

Capacitance value series

【Unit pF】

3 P 5 P 8 P 10 P 12 P 15 P 20 P 39 P 43 P 47 P

51 P 56 P 62 P 68 P 75 P 82 P 91 P 100P 120P 150P

180P 200P 220P 240P 270P 300P 330P 360P 390P 470P

560P 620P 680P 750P

【Unit nF】

1.0 1.2 1.5 1.8 2.2 2.7 3.3 3.9 4.7 5.6

10 15 18 22 27 33 39 56 68 82

【Unit uF】

0.1 0.15 0.22 0.33 0.47 1.0 (1.5) 2.2 3.3

The calculation method of capacitance is like this:

AX means A (usually two digits) multiplied by 10 to the power of x pF, so 104 is 0.1uF.

The representation method of resistance is the same.

For example, the resistance of 103 represents 10 000 ohms, which is 10K, and 102 is 1K.

Some capacitors are labeled 474, then it means 0.47uF plus some:

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