you need varistors and tvs“s
I have build a spiral generator... dint work exactly as i expected... i did the two foil one using two kraft papers of isolation the foils had 5cm or 6cm x 3m than filled on oil i think there was 30 turns or so...... and pulsed .... maybe with an Halfbridge could have worked better.,,, i have tried charging thru a charging resistor and switch direct...
i want to change to plastic,,, the capacitance was 100nf between the foils...