Electronics > Beginners
Controversy on Transistor Testing: Can't be both!
billbyrd1945:
Thank you sir! Back to the drawing board.
rhb:
Around 1979 I had built a number of simple things using a package of Radio Shack 2N2222s that did not work. I became convinced that either the transistors were all bad or the pin out on the package was wrong. I went around asking everyone I knew how to identify C & E. No one knew and this included the ex-Navy techs who did all the exotic lab instrument repairs such as X-ray diffraction machines and such.
When I heard the explanation from the physicist. I didn't run home because it was over a mile and up and down hill, but I went as quickly as I could walk which is 4-5 miles per hour. I pulled one of the remaining transistors out of the package and tested it. C & E were opposite the package labeling.
After that I had great fun with anyone I ran into who was seriously good at electronics. I'd ask them. I have only encountered a couple of people who knew, and only in the last 5-10 years.
I look forward to a post from you saying the problem is resolved. If not, I look forward to resolving it. Can't always get it right the first time. I've never played with big transistors, just small ones.
Wimberleytech:
--- Quote from: rhb on December 07, 2018, 04:30:38 am ---I look forward to a post from you saying the problem is resolved. If not, I look forward to resolving it. Can't always get it right the first time. I've never played with big transistors, just small ones.
--- End quote ---
BE reverse breakdown will be relatively low (5-10 volts).
BC reverse breakdown will be relatively high (>20 volts).
Using a simple single-trace curve tracer, you can test this readily, or with a sufficient power supply and limiting resistor.
Wimberleytech:
Here is my junction tester (curve tracer) that I built in 1974 or '75. It is currently connected to my analog scope (465B) in a dedicated test setup.
rhb:
That's just an octopus! That's not a curve tracer for determining transistor parameters. The octopus is a great diagnostic tool, but it will not give you they kind of results a Tek 577 gives. The OP is wanting a cheapie and small 577.
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