Still having a problem understanding this aspect of LT Spice.
Say I draft a circuit. I must put a (voltage) source in - say sine at a constant frequency
eg SINE 0 10 150.
If I then want to see what happens to that circuit across a range of frequencies I must insert a .ac command, which allows me to specify a start and stop frequency.
eg: .ac lin 50 100 1000
when I do this I get an error saying
No AC stimulus found: Set the value of a current or voltage source to "AC 1." to make it behave as a signal generator for AC analysis.
I'm clearly not understanding dot commands (and probably lots of other things) - but I thought I *had* set an AC stimulus with the SINE "generator device" (A circle with a + - in it and the word SINE and along side it. I also thought (perhaps) the frequency arg in the sine command would be replaced by the frequence sweep in the .ac command - but it seems it completlely separate.
Please? explain what I should do to do this correctly. Thanks