I know this circuit is dangerous, but i made it anyway (probably a mistake)-https://www.instructables.com/id/Variable-voltage-ignition-coil-power-supply/
In my circuit, I used a small ignition coil with relativity little insulation, and a 5nf capacitor with 240v AC. The circuit did not create a spark, thus leaving it with an open secondary winding. I have heard that this is supposed to damage the coils, as the voltage builds up inside the wingdings and eventually shorts through the coils internal insulation (from primary coil to secondary coil). However, i'm not too sure if this would have been a problem, as the minimum capacitor rating for the circuit was 1uf, and I used a 5nf. I also only ran the coil for around a minute overall. Can someone tell me if the coil is likely significantly damaged, as it is a backup for the ones in my car, and I would still like to use it if any of my cars current coils were to die. Please anybody?