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green said:Hi there,
I got a transistor, but I do not know whether is is a NPN or PNP. Anyone know how to determine the transistor type with multimeter ? Thanks.
green
Jay.slovak said:You can test that transistor as it's like two diodes in one package....
fsahmed said:Jay.slovak said:You can test that transistor as it's like two diodes in one package....
In addition, remember that the diode from collector to base has less junction voltages than the emitter to base diode, should u use diode tester that gives junction voltages (knee voltages) as well. This is because emitter is heavily biased as compared to the collector.
Yes, it's a pretty comon practice when one doesn't know the transistor type. Interesting to see that you didn't know this :wink: (considering your many years of experience, no offense).Nigel Goodwin said:fsahmed said:Jay.slovak said:You can test that transistor as it's like two diodes in one package....
In addition, remember that the diode from collector to base has less junction voltages than the emitter to base diode, should u use diode tester that gives junction voltages (knee voltages) as well. This is because emitter is heavily biased as compared to the collector.
I didn't know that? - I'll have to give it a try!.
eblc1388 said:Just measured three transistors, using the "diode" range on a DVM.
2SB621: PNP small signal, difference of 5mV
2N5551: NPN small signal, difference of 8mV
NPN TO3 size, unknown part number: difference 3mV
I think I will stick to my "beta" measurment method which served me good for many years and which gives a very big difference than the above.
fsahmed said:But the point is that it works!!!!
eblc1388 said:But it doesn't work on my multimeter(with a pointer) that I use 99% of the time for troubleshooting and testing LEDs.
i_build_stuff said:Speaking of modern equipment, some transistor checkers will give the type (npn or pnp), pinout and dc gain all in one shot.