How can I break-in a new transistor before I install it to an amp?
Can anyone please post a circuit that I can build and some guidelines to follow.
My country (Philippines) is plagued with counterfeit transistors and that is why I desperately need to break-in the transistors that I will buy. I don't want to end up blowing my speakers.
Jojo
Can anyone please post a circuit that I can build and some guidelines to follow.
My country (Philippines) is plagued with counterfeit transistors and that is why I desperately need to break-in the transistors that I will buy. I don't want to end up blowing my speakers.
Jojo
JojoD818 said:How can I break-in a new transistor before I install it to an amp?
Can anyone please post a circuit that I can build and some guidelines to follow.
My country (Philippines) is plagued with counterfeit transistors and that is why I desperately need to break-in the transistors that I will buy. I don't want to end up blowing my speakers.
Well, if you're just worried about blowing your speakers, here ya go:
<center>
<img src="http://www.q-audio.com/images/load.jpg">
</center>
Guaranteed not to so much as give your speakers a woody let alone blow 'em.
se
Re: Torture test...
Well, you could build a duplicate amp circuit just for testing if you want to see if a particular transistor will work in that particular circuit.
If you want something a bit more geralized, check out Rod Elliot's transistor tester at:
<a href="http://sound.westhost.com/project31.htm">http://sound.westhost.com/project31.htm</a>
se
JojoD818 said:
Well, you could build a duplicate amp circuit just for testing if you want to see if a particular transistor will work in that particular circuit.
If you want something a bit more geralized, check out Rod Elliot's transistor tester at:
<a href="http://sound.westhost.com/project31.htm">http://sound.westhost.com/project31.htm</a>
se
On page 3 of this link http://www.passdiy.com/pdf/a75p2.pdf there is a circuit for mosfet testing. You may built something similar to break in the individual transistors.
Jojo,
What you want to do is to verify that the transistors work
as advertised? Several of these circuits should work
for small signal transistors. A transistor curve tracer
would be REALLY nice for your checking.
Also, I'd figure some way to run some reasonable amount of
power on the power transistors as it seems that many
counterfeit power transistors have very tiny die. Thus
the only way to discover this is to set up the transistor
to dissipate a reasonable amount of power -- something
that the genuine transistor should be able to handle
but will fry the imposter.
One could also x-ray the transistors to see what the inside
looks like.
Many imposters also have package molding and/or markings
that don't look like the genuine article. Manufacturers
usually have their standard marking drawings somewhere
on your web sites. Comparison of your parts to the drawings
should be instructive. You might also check your devices
against known genuine transistors or pictures of the
genuine article.
What you want to do is to verify that the transistors work
as advertised? Several of these circuits should work
for small signal transistors. A transistor curve tracer
would be REALLY nice for your checking.
Also, I'd figure some way to run some reasonable amount of
power on the power transistors as it seems that many
counterfeit power transistors have very tiny die. Thus
the only way to discover this is to set up the transistor
to dissipate a reasonable amount of power -- something
that the genuine transistor should be able to handle
but will fry the imposter.
One could also x-ray the transistors to see what the inside
looks like.
Many imposters also have package molding and/or markings
that don't look like the genuine article. Manufacturers
usually have their standard marking drawings somewhere
on your web sites. Comparison of your parts to the drawings
should be instructive. You might also check your devices
against known genuine transistors or pictures of the
genuine article.
exactly...
Brian,
That is exactly what I had in mind. You see, if an original transistor can handle the power, then a counterfeit surely won't since it is loosely spec'd to keep down it's cost.
In my country, original and counterfeit components are almost the same price! Even the most reliable suppliers here sometimes sell fake/counterfeit parts.
If I burn a circuit, for example an amp, I would be happy to admit it's my fault/error and not because of a whimpy component. I'd rather subject a power transistor for burn-in than to expose the whole project to danger.
If you do have a simple circuit that can burn-in a power transistor, please let me know.
Thanks,
Jojo
Brian,
That is exactly what I had in mind. You see, if an original transistor can handle the power, then a counterfeit surely won't since it is loosely spec'd to keep down it's cost.
In my country, original and counterfeit components are almost the same price! Even the most reliable suppliers here sometimes sell fake/counterfeit parts.
If I burn a circuit, for example an amp, I would be happy to admit it's my fault/error and not because of a whimpy component. I'd rather subject a power transistor for burn-in than to expose the whole project to danger.
If you do have a simple circuit that can burn-in a power transistor, please let me know.
Thanks,
Jojo
Do you mean to test it for gain, etc. or to actually put a load on it and, what we call, "burn it in"?
If to "burn in" yeah, you probably need to build a test amp, just something real simple. Put a variable supply on it to see if it will withstand the voltage and a good heatsink for power.
Sorry, that's the best I can do,
Chris
If to "burn in" yeah, you probably need to build a test amp, just something real simple. Put a variable supply on it to see if it will withstand the voltage and a good heatsink for power.
Sorry, that's the best I can do,
Chris
Jojo
If you have a power supply with current
limiting or can put together some approximation
using 3-pin regulator chips, you should be
able to make something.
use a separate smaller supply with a 100 Ohm (?)
series resistor to the base.
By fiddling with the voltage and current-limit
settings on the main supply as well as the
base drive on the second supply, you should
be able to create a condition of reasonable
dissipation with some amount of protection to
the device. But then again, if you do the
wrong thing you can pop a good transistor.
I've always had access to a curve tracer to
do any testing/frying of discrete devices.
If you have a power supply with current
limiting or can put together some approximation
using 3-pin regulator chips, you should be
able to make something.
use a separate smaller supply with a 100 Ohm (?)
series resistor to the base.
By fiddling with the voltage and current-limit
settings on the main supply as well as the
base drive on the second supply, you should
be able to create a condition of reasonable
dissipation with some amount of protection to
the device. But then again, if you do the
wrong thing you can pop a good transistor.
I've always had access to a curve tracer to
do any testing/frying of discrete devices.
This is what I use, I whipped it up a little while ago, I have a few hundred fets to test. I can check 8 devices simultaneously, 4 N Channel and 4 P channel. The knobs and switches control Meter outputs and VCC supplies to each Bank.
Anthony
An externally hosted image should be here but it was not working when we last tested it.
Anthony
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