Graphic divisor

[marc1996]

Hello to everyone,

I have one voltage and current waveform graphics and I would like to divide them in order to get the resistance value in time domain. Do you know if this is possible with any software or something?

Voltage and current waveforms are not proportional. Values from both graphics are taken in the same moment and the graphics are exported from LTSpice.

Thanks for your help!

[Nominal Animal]

I normally use command-line tools like awk and gnuplot for such things, and was going to write an answer on how to do it, but then I vaguely recalled that LTspice's plot view ought to have an expression editor. (I'm not even sure if I've used LTspice except for some experiments, however, so the following is basically all I know; hope it helps.)

Looking at LTspice Tips at Digikey, you can add a new trace to the plot in the WaveForm Viewer, and change its expression to V/I (assuming the voltage trace is named V and the current trace I ). So, you should be able to do this in LTspice WaveForm Viewer.

[Z80]

If you are using LTSpice then it's easy to do by adding a new trace.
With the plot window selected, press <Ctrl> A to add a trace (or right click in the plot window or select from the plot settings menu).
Select the voltage node you want to use from the list, type / after it then select the current from the list and click OK.  The new resistance trace will be added to the plot complete with an ohms scale.

[Zero999]

Yes, it can be done in LTSpice. Label the voltages and use V(label)/I(component) in the graph properties window.


https://www.eevblog.com/forum/beginners/passive-components-in-guitar-pedal-input-stage/msg1753601/#msg1753601