Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Solid State => Topic started by: plexi50 on October 26, 2011, 06:13:57 pm
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I found this video on youtube that shows how to test your questionable transistors
I like the biasing part that determines the Collector,Base,Emitter/ What if the transistor will only bias up on one side? Is the tansistor bad?
Transistor Testing, the Basics (http://www.youtube.com/watch?v=EcfGXHoWiZ4#ws)
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OK<
From what I get from watching the vid is this.
It does not determine if the transistor is good or bad.
It does show how to identify PNP or NPN and which lead is B base
Then we learn by biasing which lead is C collector
By default the last lead is E emitter.
SO by "biasing" we put a resistor between the C and B and not E and B so it does only bias on 1 side.
At least that's my take on it.
I never trusted anything I couldn't solder with a big Weller soldering gun any how :laugh: so take what I think with a grain of salt!
ray
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Notice it is an analog needle-meter, NOT a DMM.
It also has 1.5V internal battery for Ohms.
Yes, it will sort _DEAD_ transistors. On this type ohm-meter, a happy junction will show infinity one way and half-scale the other way, on all ranges. Sick junctions show dead-short. Sick junctions with huge power available will be found blown-Open.
Such technique can not tell E from C (but on TO220, TO3, TO5 you already know the tab/case is C). You need to test for current gain or junction breakdown to tell E from C.