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Transistor identification

post #1 of 9
1/27/10 at 3:54am
Thread Starter 
I ordered myself a set of Toshiba transistors on eBay as is common, and I just ordered myself a set from MCMinOne (specifically, 2SC2238/2SA968) and I'm wondering if there's a way I can compare the two to determine if the ones I purchased on eBay are legitimate or not (I paid about the same price per unit both places).

I read something about measuring the resistance between the Collector and the Emitter (I believe), but part of me wonders about the accuracy of that method.

Any help is much appreciated.
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post #2 of 9
1/27/10 at 2:44pm
See if the local tech school, or college will allow you time on their curve tracer.
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post #3 of 9
1/27/10 at 9:51pm
You can build a simple jig on the bench and take measurements for Idss and Vgs at different gate voltages or inline resistance/power supply voltages and trace a curve on a piece of paper yourself. It would be simple and quick. You would have to do it for more than a couple of devices to have any type of accuracy though. You could compare your results with the curves in the datasheets. I could be done with some batteries and a handful of resistors.
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post #4 of 9
1/27/10 at 10:54pm
...or you could compare the curves of each device. And of course, you could listen to them in the actual circuitwhen you're finished testing.
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post #5 of 9
1/27/10 at 11:13pm
Thread Starter 
Thanks for the advice. I seem to be lacking a place that has a decent curve tracer and given I don't have a heck of a lot of patience for testing and graphing, I've looking into DIY units and I found Circuit-Ed - Electronic Development Products this gem.

Has anyone used this unit to know how good it is?
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post #6 of 9
1/28/10 at 12:34am
That tool looks pretty handy. I've only used the giant curve tracers which look as though they've been pulled from a battleship.
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post #7 of 9
1/28/10 at 1:16am
It seems a lot of money to test a $2 transistor, why not just try them in the circuit?
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post #8 of 9
1/28/10 at 1:21am
Thread Starter 
Quote:
Originally Posted by Fred_fred2004 View Post
It seems a lot of money to test a $2 transistor, why not just try them in the circuit?
Well I bought quite a few, but mostly I'd like to get it for future use as well.

I'd also like to get a more objective standpoint on the transistors if possible.
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post #9 of 9
1/28/10 at 8:00am
One should always be suspicious against sought after obsolete parts, especially from the far east. Better to use modern parts from a reputable seller.
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