(1) Straight labeling method: use letters and numbers to directly label the model and specifications on the casing.
(2) Text symbol method: use regular combination of numbers and text symbols to represent capacity. The text symbol indicates the unit of its capacitance: P, N, u, m, F, etc. The same as the resistance. The nominal allowable deviation is also the same as the resistance representation method. For capacitors less than 10pF, the allowable deviation is replaced with letters: B-± 0.1pF, C-± 0.2pF, D-± 0.5pF, F-± 1pF.
(3) Color scale method: It is the same as the expression method of resistance, and the unit is generally pF. The withstand voltage of small electrolytic capacitors is also color-coded. The position is close to the root of the positive lead, and the meaning is as follows:
Color Black Brown Red Orange Yellow Green Blue Purple Gray
Withstand voltage 4V 6.3V 10V 16V 25V 32V 40V 50V 63V
(4) Marking method for imported capacitors: Imported capacitors generally consist of 6 items.
Item 1: Use letters to indicate categories:
The second item: use two digits to express its appearance, structure, packaging method, start of lead and relationship with the shaft.
The third item: the temperature characteristics of temperature-compensated capacitors, with letters or colors, the meaning is shown in the following table:
No. Letter Color Temperature Coefficient Allowable Deviation Letter Color Temperature Coefficient Allowable Deviation
1 A gold +100 R yellow -220
2 B gray +30 S green -330
11 P Orange -150 YN -800 ~ -5800
Note: The unit of temperature coefficient is 10e -6 / ℃; the allowable deviation is%.
The fourth item: use numbers and letters to express the withstand voltage, the letters represent effective values, and the numbers represent the power of 10 of the multiplicand.
Item 5: Nominal capacity, represented by three digits, the first two are valid values, and the third is a power of 10. When there is a decimal, it is represented by R or P. The unit of ordinary capacitor is pF, and the unit of electrolytic capacitor is uF.
Item 6: Allowable deviation. With a letter, the meaning is the same as domestic capacitors.
The color coding method is also used, which has the same meaning as the marking method of domestic capacitors.
Imported, take 477 A71N13 as an example, the six digits at the back correspond to the six items above