Super Practical Tips: Inspection Requirements And Methods Of Electronic Components----Resistors

Electronic component knowledge - resistors


Classification of resistors: ① wirewound resistors ② thin film resistors: carbon film resistors, synthetic carbon film resistors, metal film resistors, metal oxide film resistors, chemical deposition film resistors, glass glaze film resistors, metal Nitride film resistors ③ Solid resistors ④ Sensitive resistors: varistor, thermistor, photoresistor, force-sensitive resistor, gas-sensitive resistor, humidity-sensitive resistor.

1. Direct marking method: Use numbers and unit symbols to mark the resistance value on the surface of the resistor. The allowable error is expressed directly in percentage. If there is no deviation noted on the resistor, it will be ±20%.
2. Text symbol method: Use a regular combination of Arabic numerals and text symbols to express the nominal resistance value, and the allowable deviation is also expressed with text symbols. The number in front of the symbol represents the integer resistance value, and the following numbers represent the first decimal resistance value and the second decimal resistance value in sequence. Text symbols indicating allowable errors: DFGJKM Allowable deviations are: ±0.5%±1%±2%±5%±10%±20%
3. Digital method: A marking method that uses three digits to represent the nominal value on the resistor. The digits are from left to right, the first and second digits are valid values, and the third digit is the exponent, that is, the number of zeros, and the unit is European. Deviations are usually represented by literal symbols.
4. Color marking method: Use bands or dots of different colors to mark the nominal resistance value and allowable deviation on the surface of the resistor. Most foreign resistors use the color marking method.
Black-0, Brown-1, Red-2, Orange-3, Yellow-4, Green-5, Blue-6, Purple-7, Gray-8, White-9, Gold-±5%, Silver-±10 %, colorless-±20%

1. Direct marking method: Use numbers and unit symbols to mark the resistance value on the surface of the resistor. The allowable error is expressed directly in percentage. If the resistance value of an electric chip resistor is identified: (Numbers are marked on the surface of usual chip resistors. Or represented by letters, the resistance value is as follows.
1. The first and second digits represent the real number of the resistance.
2. If the number starting with the third digit is 0, it represents dozens of ohms (between 10 and 99 ohms): 100 is a 10 ohm resistor, and 990 is a 99 ohm resistor.
3． If the number starting with the third digit is 1, it represents several hundred euros (between 100 and 999 euros). For example: 101 is 100 euros, 151 is 150 euros, and 951 is 950 euros.
4. If the number starting with the third digit is 2, it represents several thousand euros (between 1000 and 9999 euros). For example: 102 is 1K, 152 is 1.5K, and 992 is 9.9K.
5. The number starting with the third digit is 3, which represents dozens of K (between 10K and 99K). For example: 103 is 10K, 223 is 22K, and 993 is 99K.
6. The number starting with the third digit is 4, which represents hundreds of K (between 100K and 999K). For example: 104 is 100K, 204 is 200K, and 854 is 850K.
7. If the number starting with the third digit is 5, it represents how many M (between 1M and 9.9). For example: 105 is 1M, 155 is 1.5M, and 955 is 9.5M.
8. If the number starting from the third digit is 6, it represents ten M (between 100K and 999K). For example: 106 is 10M, 566 is 56M.
9. The standard method for four numbers is that the first three digits are real numbers, and the fourth digit is a multiple. 1001 is 1K, 1002 is 10K, and 1005 is 10M.