[sdiy] transistor matching circuit

[Theo]

Basically a saw (tri or sine also kind of works) oscillator and a current to
voltage converter.
Its used to draw a Vin vs. Vout or V vs. I "curve" on a scope.

Basic patch:
Put the scope in X-Y mode.
Feed the saw wave to both scope X and the circuit/device under test.
Output of the circuit/device to the Y input of the scope.
The scope then shows the Vin / Vout function of the circuit.

Obviously to show a V/I function you need a way to "measure" current with
the scope.
This is where the current to voltage converter gets into play.

Cheers,
Theo
(Been away a while, still 2583 unread messages to go)



----- Original Message -----
From: Tom Arnold <xyzzy at sysabend.org>
To: Peter Grenader <peter at buzzclick-music.com>
Cc: SDIY <synth-diy at dropmix.xs4all.nl>
Sent: Wednesday, December 15, 2004 12:18 AM
Subject: Re: [sdiy] transistor matching circuit


> On Tue, Dec 14, 2004 at 03:17:26PM -0800, Peter Grenader wrote:
> > There a few of curve tracer scope fixtures on ebay right now going
pretty
> > cheaply - under $50. The full blown tek's with the tube displays are
still
> > pricey at about $500
>
> Pardon me for being dense, but what exactly is a curve tracer?
> I see them surplus all the time for cheap but never paid much attention to
> them.
>
> --
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