NPN Transistor

[Bartx7000]

I have a working transistor but the label is missing. How do I find out what it is? I think it is a NPN. It is a power transistor in a T0-3 package. Is there anyway to figure out what it is?
Thanks in advance

 

[bogdanfirst]

well it 's quite hard. if you know wich pin is wuch, mesure its Hfe, with a multimeter that is specialized it this. but other properties, its quite hard to determine.
for example if you try to find out the maximum current that it supports, you can only find that after you burnt it. so its quite hard

 

[Bartx7000]

Thanks what is HFE. I have a multimeter that has a transistor testor or so i thnk because it has a NPN and a PNP with the E B C E holes on both sides. Is this what u are referign to.
Thanks Again

 

[bogdanfirst]

Hfe or B(beta, but i cant write that) is the amplification of the transistor, or the gain. this is what the multimeter mesures, but it is not enough to identify the transistor. there are a lot of transistors that have anout the same gain, but some have a gain wich can be different from transistor to transistor, for example, a BC107 would hava a gain >110, so you might expect 120 of maybe even 200!, so its not quite relevant to mesure the hFE(this is the way it is written, sorry for writing it in a different way, but i wasnt pying attention.

 

[kinjalgp]

Exact Definition: Beta or hFE is the current gain of transistor in common-emitter configuration.

 

[bogdanfirst]

thnaks for corrcting me. i dont want to tell lies. i never remember the definitions exactly, eventhough i apply it in practice.