MIL-STD-750-3 Transistor Testing

[mityeltu]

I just want to check my sanity...

I am going to be testing some transistors in a lab very soon per the above mil std. The test methods range from Vce, Vbe, hfe and the breakdown voltages that are listed on the datasheet. The transistor at this point is irrelevant.

Here's what I need to understand. According to the mil std, the circuits are all drawn for PNP trnsistors in one configuration. That's fine. However, I will most,likely be testing NPN transistors. So, if I understand this right, all I need to do is reverse the polarity of the sources and test equipment (ammeter, voltmeter) in order to correctly perform the tests per this std. Is this right?

 

[mityeltu]

Don't everybody answer at once.

 

[petersonra]

Don't everybody answer at once.

perhaps no one here is familiar with this test std and thus no one here feels qualified to answer.

your suggestion sounds more or less reasonable but whether it meets the requirements of the std is something else.

Personally, i have not heard of anyone testing transistors by hand this way real recently. Normally the manufacturer would test them and include a certificate of conformance so you would not need to test them.

you could also buy a transistor tester or just have someone do it for you. some of these tests look a lot simpler than they really are.

 

[hbiss]

some of these tests look a lot simpler than they really are.

Back in the 70s I was with a company that made equipment to do just that. Manufacturers like Boeing Aircraft used them for incoming inspection and that was to mil spec. The equipment was crude by today's standards but still used the days "PC computer"- the DEC PDP 11 to run all the tests.

perhaps no one here is familiar with this test std and thus no one here feels qualified to answer.

Really not the right forum to ask this.

-Hal

 

[mgookin]

When I worked in defense manufacturing our plant had to test every component as it came in.
Every resistor, capacitor, transistor, etc.
Everything.

 

[junkhound]

When I worked in defense manufacturing our plant had to test every component as it came in.
Every resistor, capacitor, transistor, etc.
Everything.

AND, if it has been on the shelf too long, gets retested. Even some simple parts like resistors/capacitors needed to have leads re-tinned before assy if on the shelf too long.

Note for those unfamiliar with aerospace: A $10 MOSFET to normal consumer specs will cost $100 after mil-spec testing in many instances, main differences is the string of letter suffixes at the end of the consumer part number. Additionally, some parts even get 'upscreened' to tighter tolerances or matching sets of parts at the mfg for critical applications, which is what OP may be testing to.

 

[jerryalan]

all you need to do is reverse the polarity of the sources and test equipment (ammeter, voltmeter) in order to correctly perform the tests per this std.

 

[junkhound]

Don't everybody answer at once.

Hazing 101:

BTW, if you are going to quote specs, at least understand the notation,
re: MIL-STD-750-3 Transistor Testing.

No one where you work knows the difference or how to test ? Or, just scared to ask as co-workers are all jerks ? Or, you misrepresented your knowledge base on the employment questionnaire ? Did someone just say, as a test, 'hey Mitt, test this part per seven five O (thr) E. Might indicate a slight hearing loss on noisy shop environment to have thought you may mis heard the 'thr' ?

Did you mean MIL-STD-750E, -- or just the 2012 version of E that puts a dash number on part 3 on the spec pages ?

BTW, didja git yer answer? Your QV says EE, you actually iz one to not know the answer yerself ? (note: see Hazing 101)

NPN are shown in part 3.