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Help to ID transistor...

G

GPE

Jan 1, 1970
0
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 [email protected]!!!!

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
 
M

Mark Harriss

Jan 1, 1970
0
GPE said:
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


You could cut one open and take a look for things like two die wired in
parallel. Also take a look at : http://sound.westhost.com/counterfeit.htm
 
E

Eeyore

Jan 1, 1970
0
GPE said:
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 [email protected]!!!!

Quite likely.

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)?

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.
http://sound.westhost.com/counterfeit.htm
http://www.google.com/search?hl=en&...sult&cd=1&q=counterfeit+semiconductor&spell=1

Graham
 
G

GPE

Jan 1, 1970
0
Eeyore said:
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.

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


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.

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

-- Ed
 
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