Discrimination of polarity and quality of transistor pins 1

The resistance range of a multimeter can be used to distinguish the polarity of a transistor and determine its quality. When testing low-power transistors, R × 100 (Q) or R × lk (Q) gears are generally used to avoid damaging the transistor.dioe

(1) Discrimination between Tube Type and Base   dioe

Set the multimeter to the resistance mode and select the range of R × lk (or R × 100). Contact any probe of the multimeter with an assumed common electrode first, and the other probe with the other two electrodes separately. When the resistance measured twice is very small (or both are very large), the electrode connected to the former is the base. If the resistance values measured twice are significantly different, the assumed base of the former is incorrect and should be replaced with another electrode for retesting. According to the above method, the common pole can be identified, which is the base b.dioe

After determining the base b, use a simulated multimeter with the red probe to contact the base b and the black probe to contact the other two pins. If the meter readings are very small (about a few hundred ohms), it can be concluded that this transistor is an NPN transistor, otherwise it is a PNP transistor.dioe