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Products => Test Equipment => Topic started by: JuanPC on August 27, 2013, 10:21:04 pm

Title: Curve Tracer with a DSO?
Post by: JuanPC on August 27, 2013, 10:21:04 pm

just wondering if there is a way to make a curve tracer with a DSO?

something like Tektronix Model 576, but not old, not cathode tube.

Title: Re: Curve Tracer with a DSO?
Post by: TerminalJack505 on August 27, 2013, 11:47:05 pm

Read this thread:

https://www.eevblog.com/forum/beginners/dirt-cheap-and-simple-scope-based-component-tester-curve-tracer/ (https://www.eevblog.com/forum/beginners/dirt-cheap-and-simple-scope-based-component-tester-curve-tracer/)

Somewhere in it, someone posted a schematic and a magazine article of a transistor curve tracer.

This post (https://www.eevblog.com/forum/beginners/dirt-cheap-and-simple-scope-based-component-tester-curve-tracer/msg119494/#msg119494), I think.

Should work with a DSO scope so long as it has an X-Y mode.

Title: Re: Curve Tracer with a DSO?
Post by: mcinque on August 28, 2013, 01:45:32 pm

Yes, it's indeed a cheap ad useful device, and it's very simple.

Take a look a the w2aew schematic that I've freely redesigned, grab a couple of bnc, a resistor and a transformer, and you're done!

Title: Re: Curve Tracer with a DSO?
Post by: alm on August 28, 2013, 01:57:55 pm

That's not really a curve trace, but more of a basic Huntron tracker tool typically used for troubleshooting. It's fine for qualitative measurements, but accurate quantitative measurements like current gain, for example to test unknown transistors or to match them, will be tricky if not impossible.

Title: Re: Curve Tracer with a DSO?
Post by: TerminalJack505 on August 28, 2013, 06:26:29 pm

Quote from: alm on August 28, 2013, 01:57:55 pm

That's not really a curve trace, but more of a basic Huntron tracker tool typically used for troubleshooting. It's fine for qualitative measurements, but accurate quantitative measurements like current gain, for example to test unknown transistors or to match them, will be tricky if not impossible.

Yeah, I wouldn't expect much for what basically amounts to $10 to $20 in parts. 

Both the octopus tracer and transistor tracer are on my "build, just for fun" list.

Title: Re: Curve Tracer with a DSO?
Post by: jancumps on August 28, 2013, 06:44:44 pm

Are you looking for a Bode plot on the scope?

https://www.youtube.com/watch?v=uMH2hGvqhlE#ws (https://www.youtube.com/watch?v=uMH2hGvqhlE#ws)

Title: Re: Curve Tracer with a DSO?
Post by: jancumps on August 28, 2013, 06:46:45 pm

Or this type of tracer:

(http://db.tt/bFoLenSt)

Title: Re: Curve Tracer with a DSO?
Post by: alm on August 28, 2013, 06:55:15 pm

The latter, given that he references the Tek 576.

Title: Re: Curve Tracer with a DSO?
Post by: jancumps on August 28, 2013, 07:03:48 pm

So that's possible. The photo is taken from my DSO :)

i used this schema from http://www.intio.or.jp/jf10zl/trct.htm (http://www.intio.or.jp/jf10zl/trct.htm)

(http://www.intio.or.jp/jf10zl/trctnewk.gif)

Works only for NPNs.