Hi Joe S,

I replaced my IGBT driver with CNY17-1 opto-coupler. That brought my circuit back to life. But the old reset problem still exists.
When I touch one of the crystal pins with a needle probe Pic locks up and when I remove the probe it starts working again. When I touch the other crystal pin or any other Pic pin nothing happens.

When I trigger the IGBT driver using Pic powered by the programmer/evaluation board. The reset problem doesn’t improve and eventually it blows the 315mA fuse in 12v power supply of the programmer. The Pic is 16f628 positioned on a sim stick that is plugged into the programmer. The 20Mhz crystal, capacitors and MCLR pull up resistor are positioned on the sim stick as well.

I replaced the secondary winding earth wire with a high-tension lead and a spark plug and attached the earth to the spark plug outer shell. That fixed the problem. Pic works stable. Though I would still like to get it to work without the additional resistance in the secondary circuit. This would make the circuit a bit more robust. I will try to get the current clamp and graph the primary current and solve the crystal problem.