Help to ID transistor...

Hi --

I have recently purchased several hundred TO-3 transistors from a well known parts dealer. I prefer not to give their name right now pending resolution to this issue...

I noticed these transistors were very nice looking, clean NOS Motorola's and thought nothing of them for awhile. In fact, I have already gone thru 200 of them.... Tonight - I noticed variations in package (tooling, etc) as well as differences in insulation around transistor leads. Normally - I would think nothing of this either. BUT -- all these transistors have the exact same date code -- 0223. And - didn't Motorola change over to On Semiconductor in 1999? Counterfeits?!?! Aw d@mn!!!!

The parts seem to work well in a simple, low current power supply. Pretty much any similar NPN transistor would work. However, this is in a relatively high voltage supply -- 160 to 240VDC. Part may be good for gain and current but could still be rated for max of 60 volts of some awful low value. These parts work but I don't want a ticking time bomb by using voltages 4x what the parts are rated for....

Is there a way I can find out what these transistors really are? If you pop the top - do any transistors have part marking internally on the die itself (i.e. etched in the corner)?

-- Ed

Reply to
GPE
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You could cut one open and take a look for things like two die wired in parallel. Also take a look at :

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Reply to
Mark Harriss

URL corrected:

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HTH.

-- Graham W

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Reply to
Graham W

Quite likely.

If you pop the lid ( I saw it off) the differences will be remarkable. Things like the die being a fraction of the size for example.

Just the difference in cans makes it clear to me they're knock-offs btw. Motorola's cans were always identical. And yes, the devices became ON ages back.

They're not audio output devices are they ? A very popular counterfeit. MJ15003/4, MJ15023/4. Very popular indeed.

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Graham

Reply to
Eeyore

I'll do this, take some pix and post links to what I find this weekend (if I get time).

These are actually simple NPN power transistors. Used for high voltage regulator.

-- Ed

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Reply to
GPE

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