matching transistors

[Harry Bissell]

I think there was one in Electronic Design magazine as an "Ideas for Design"
article...

It used a triangle wave generator and the two trannies as a log/antilog circuit
and would
draw a matching curve on your scope. Search their web site and you will find. If
I find
my copy I'll post the date of the issue...

H^) harry

Jay Martin wrote:

> Electronics Now had a circuit (last year I think) that made that job real
> easy.  If I remember it took the transistors under test and biased them the
> same.  It then sent the outputs into opposite sides of a standard op-amp and
> introduced a sweeping signal to the transistor pair.  If the transistors
> were "matched" there would be no output (or very little anyway) from the op
> amp.
>
> I'll see if I can find it over the weekend.  Otherwise the above should be
> enough to re-create the idea.
>
> Jay Martin
>
> -----Original Message-----
> From: Bipin E Butala [mailto:buta0006 at tc.umn.edu]
> Sent: Thursday, June 29, 2000 4:12 PM
> To: synth-diy at node12b53.a2000.nl
> Subject: matching transistors
>
> hi i was curious is anyone knew where i could find instructions
> on how to match transistors. i heard that it is described in old
> moog manuals but unfortuantly i don't have one of those..:-(
>
> thanks,
>
> bipin