How does a multimeter measure each pin of a triode?
Answer: There is a power supply inside the analog multimeter, the outer black test lead is connected to the positive pole of the power supply, and the outer red test lead is connected to the negative pole of the power supply.
(1) When measuring the base, emitter and collector of NPN transistors, the steps are as follows:
First determine the base (b): first adjust the multimeter to the ohm range, connect one pin with a black test lead, and then touch the other two pins with a red test lead. If the multimeter has a large deflection, connect the black test lead to The pin is the base (b). If the phenomenon is not the case, exchange the pins until the phenomenon occurs.
Then determine the emitter (e) and collector (c): After the base is determined, use the red and black test leads to touch the other two pins respectively, and connect the human body resistance between the base and the black test leads. If the multimeter has a large deflection, the black test lead is connected to the collector, and the red test lead is connected to the emitter. If there is no such phenomenon, reverse the red and black test leads until this phenomenon occurs.
(2) When measuring the base, emitter and collector of PNP transistors, the steps are as follows:
First determine the base (b): first adjust the multimeter to the ohm range, connect one pin with a red test lead, and then touch the other two pins with a black test lead. If the multimeter has a large deflection, connect the red test lead to The pin is the base (b). If the phenomenon is not the case, exchange the pins until the phenomenon occurs.
Then determine the emitter (e) and collector (c): After the base is determined, use the red and black test leads to touch the other two pins respectively, and connect the human body resistance between the base and the black test leads. If the multimeter has a large deflection, the red test lead is connected to the collector, and the black test lead is connected to the emitter. If there is no such phenomenon, reverse the red and black test leads until this phenomenon occurs.
