I'm having trouble getting an AC simulation to work in 7.0.5. Could be I am just not doing something right but 'the obvious' things don't work - nor does 'doing something similar to what I do in LTSpice' work.



I can set up a Transient simulation just fine.



However attempting to set up and run an AC simulation doesn't seem to want to let me add signals, and it just pops up an error message telling me to 'run the simulation first'. If I run the simulation again, it just gives me another Transient simulation!



Any idea what I am doing wrong, or should I be filing a bug report?

开云体育

Not sure- but it would look like Q3 may be saturated.

I'm having trouble getting an AC simulation to work in 7.0.5. Could be I am just not doing something right but 'the obvious' things don't work - nor does 'doing something similar to what I do in LTSpice' work.



I can set up a Transient simulation just fine.



However attempting to set up and run an AC simulation doesn't seem to want to let me add signals, and it just pops up an error message telling me to 'run the simulation first'. If I run the simulation again, it just gives me another Transient simulation!



Any idea what I am doing wrong, or should I be filing a bug report?

开云体育

It surely is. The base voltage and R5 indicate a current of about 6 mA, which doesn't work with R4 being 17.8 k. I've never seen a concertina phase-splitter with different collector and emitter resistors. R2 and R? look wrong as well. Q1 and Q2 bases are both at about 8 V.

Thanks - the circuit, as you have pointed out, has not yet had the benefit of 'design', merely 'simulation'.

However I am still not understanding why I can't seem to perform an AC analysis (presumably, even once the circuit is properly designed).

If the output is a dc level, it will quite fairly refuse an ac sweep.

As others said, this type of circuit (phase splitter?) should swing the output around 0V.
You wouldn't expect a network analyser in the real world to show a bode plot if the circuit between is not functioning.

I am a beginner with KICAD sims, but LTSPICE is fairly familiar.

OK, perhaps I should rephrase my question as the poor circuit I posted seems to be preoccupying the discussion.

Could anyone please post an example of a successful AC response produced using the latest KiCad? So I can see how it is done in general? Any illustrative circuit example would do, forget the one I posted above. I'm trying to understand if it works and how I can get it to work for me.