Question - Building a curve tracer

[Electron Tornado]

I'm building a curve tracer based on an octopus circuit, but with a sin wave generator to give variable frequencies.

Here is a question - what voltages would be most useful for the sin wave signal? Voltages of 1V and 100mV would be useful. Any others?

 

[GibsonGM]

I don't know, but I'd like to see the circuit to adapt an octopus into a curve tracer...

[PRR]

to adapt an octopus

https://www.nutsvolts.com/magazine/article/build-an-oscilloscope-octopus

[merlinb]

Here is a question - what voltages would be most useful for the sin wave signal? Voltages of 1V and 100mV would be useful.   

Why not use a pot so you can have any amplitude of sine?

[GibsonGM]

to adapt an octopus

https://www.nutsvolts.com/magazine/article/build-an-oscilloscope-octopus

Thanks, Paul...I have an octopus....curious how you'd take that and build what the OP is trying to do, variable frequency and so on.  Thus far doing it manually on paper (for tubes) has worked out fine tho.

[Electron Tornado]

Here is a question - what voltages would be most useful for the sin wave signal? Voltages of 1V and 100mV would be useful.   

Why not use a pot so you can have any amplitude of sine?

I thought of that, but it doesn't seem that there needs to be that fine of a control over the test voltages. Examples I've seen use whatever voltage they get from the AC transformer secondary as their max test voltage with a voltage divider selecting a few different voltages.

[Electron Tornado]

Thanks, Paul...I have an octopus....curious how you'd take that and build what the OP is trying to do, variable frequency and so on.  Thus far doing it manually on paper (for tubes) has worked out fine tho.

With a simple octopus, you are limited to a single test frequency of 50/60Hz. The Huntron Tracker has more than one frequency available. An octopus is just a sine wave at a certain (or selectable) voltage with current limiting. So, why not use a sine wave oscillator with variable frequency? That might be more useful when testing reactive components. My question on test voltage may just come down to what is the max voltage I really need? That drives the power supply design as well as how much the sine wave needs to be amplified.

From what I've read of other octopus designs, the max voltage is probably not terribly critical, though I would like to know if there is a recommended maximum.