Hello - I'm trying to understand this circuit that drives a piezoelectric transformer to create high voltage AC at a sharp emitter point that generates positive and negative ions. At first glance I thought it was a Wien bridge oscillator followed by gain and a push-pull amplifier to drive the primary of the piezoelectric transformer. A closer look has left me confused. I don't understand why there is a capacitor (C5) between the output of the op-amp and the feedback and can't properly...
Trying to understand AC ionizer circuit