Multimeter to measure transistor

youganw

Multimeter to measure transistor [Copy link]

1. Judging whether it is good or bad: Basic idea: For NPN type, there are ① whether the P in the middle to the N on both sides (P→N) are all forward biased; ② whether the N on both sides to the P in the middle (N→P) are all reverse biased. If ①② are satisfied, it is a good NPN type; If ① is not satisfied and ② is satisfied, it is an open circuit problem; If ① is satisfied and ② is not satisfied, it is a short circuit problem. Specific operation: ① Ohmmeter R×100 or ×1k, black test pen (high potential) connected to the middle base b, red test pen (low potential) connected to the other two poles, whether the resistance value is very small (the pointer deflection angle is large); ② Red test pen (low potential) connected to the middle base b, black test pen (high potential) connected to the other two poles, whether the resistance value is very large (the pointer deflection angle is small). 2. Basic idea of determining the base level: Since there must be a section from N to P (i.e. reverse bias) between the collector and emitter of the transistor (NPN or PNP), its essence is that after multiple verifications, if both the forward and reverse connections are reverse biased, then the remaining one is the base level. Specific operation: Use the ohmmeter R×100, and the red and black test leads to measure any two pins in the forward and reverse directions multiple times. If the resistance values measured are both very large at a certain time, the remaining pin is the base level b. 3. Basic idea of determining the type: For the NPN type, from the middle P to the N on both sides (P→N) are all forward biased; otherwise, it is PNP. Specific operation: Use the ohmmeter R×100 or ×1k, and connect the black test lead (high potential) to the middle base level b, and the red test lead (low potential) to the other two poles. If the resistance values are very small (the pointer deflection angle is large), it is NPN; if the resistance values are both very large, it is PNP. Recommended dry goods, welcome to share~

maychang

The operations described in the article are limited to pointer multimeters and cannot be judged in this way for digital multimeters.

star_66666

This is absolutely good

m19924568701

Awesome!