How to Test 2N3055

[I'mClueless]

Hello,

I purchased some 2N3055 transistors through eBay today and they were manufactured in India by Continental Device India Limited. It will be awhile before I will have all of the components to build the target project so I would like to know how to test the 2N3055 transistors. This is my first experience with transistors.

Yep,
I'mClueless

 

[bychon]

I'm sure the real smarty pants will have plenty of corrections for me, but when I was a young skinny person, I built a 70 volt DC supply and added a 68 ohm resistor, a switch, a 1k resistor, and an amp meter. I used alligator clips to connect each transistor up in the correct polarity at the collector and emitter with a 1k resistor from base to emitter. Turned on the 70 volts, and some of them shorted right there. Then I pressed the switch to allow 1 amp into the base, saw the meter show current flow, and let off the connection. If the transistor stopped, I called it good. Forty percent of the Mexican counterfiets failed. Then we built over a hundred multi- transistor power supplys. In the first year, 2 came back. One had a bad regulator chip and one had somebody stick a screwdriver in it and break the trim pot. The rest kept working and I never saw them again.

 

[MikeMl]

(Data sheet) Connected like this, the lamp should be off with the switch open, and fully on with the switch closed. The battery needs to supply ~2A. This is a basic test of the ability to stand off 12V when off, and switch 2A with a ~min Hfe of about 20.

 

[audioguru]

The transistors that are made in India might be fakes. Since you bought them on E-Bay then they are probably "seconds" that do not meet spec's anyway.

I would have bought American transistors from a reputable distributor like Digikey.

 

[I'mClueless]

audioguru,

The transistors that are made in India might be fakes.

Yes, that is why I want to test them right away.

Yep,
I'mClueless

 

[audioguru]

Yes, that is why I want to test them right away.

Is it worth the hassle of testing many spec's of the transistors?

I bought thousands of transistors and opamps made by American maufacturers from Digikey. They are honourable so every one worked perfectly without me testing them. But I tested every one of my finished products because a capacitor was shorted and an IC was inserted backwards.

 

[I'mClueless]

audioguru,

Is it worth the hassle of testing many spec's of the transistors?

Well the answer to your question is NO

Perhaps a better question would have been whether or not I'm qualified to verify all of the spec's

The answer is still NO.

I have contacted six other buyers and five have replied stating that the transistors were good.

Do I have knowledge of their credentials?

The answer is still NO.

Would I buy more of the transistors?

The answer is still NO.

Have I missed anything?

Yep,
I'mClueless