I have this test circuit, which has this signal:
V1 may change from 1 to 30 V, V2 may change from 0 to 4 V peak to peak.
I need to clip the signal at about 3 - 4 V to feed it to an Op Amp, which has a split supply voltage of about -5 and +5 V.
So I added two zener diodes and the signal was...