Uploaded March 2023 | Updated September 2026, 2 weeks ago
I'm slow to test the limits because of how much of a pain it would be to replace any of the IGBT's before even finalizing the bridge but I may need to move on to an HV charger to one-shot higher and higher voltages before investing in a doubler. I made an identical PLL feedback circuit for this so I didn't have to borrow it from my other build, then routed everything inside the box so it's easy to take anywhere and power from the 20V battery. This thing is already impressive enough to me at just a little over 100VDC ramps that I might keep using secondary feedback for a while. I can start to hear a little noise now when going over 100VDC though so this might be the result of not isolating the signal wires.
Using the inverter I can probably get a max of 140VDC ramps If I crank the variac all the way up at ~10ms or so on times.
The current test coil is pretty similar to the new one I wound but swapping that one in would require a new primary I just don't feel like winding yet. So far the ramp and the output seems pretty clean and all I'm really missing is a fan for running mains at higher BPS and something like a 2uF snubber for the bridge. Every now and then when briefly pushing it to like 120VDC I'll see some 3ft or so arcs, and how consistent the swords are seems really dependent on the topload and breakout point. I want to play around with this arrangement to see if I can maybe hit about 4 ft arcs before going dual resonant.
I'm slow to test the limits because of how much of a pain it would be to replace any of the IGBT's before even finalizing the bridge but I may need to move on to an HV charger to one-shot higher and higher voltages before investing in a doubler. I made an identical PLL feedback circuit for this so I didn't have to borrow it from my other build, then routed everything inside the box so it's easy to take anywhere and power from the 20V battery. This thing is already impressive enough to me at just a little over 100VDC ramps that I might keep using secondary feedback for a while. I can start to hear a little noise now when going over 100VDC though so this might be the result of not isolating the signal wires.
Using the inverter I can probably get a max of 140VDC ramps If I crank the variac all the way up at ~10ms or so on times.
The current test coil is pretty similar to the new one I wound but swapping that one in would require a new primary I just don't feel like winding yet. So far the ramp and the output seems pretty clean and all I'm really missing is a fan for running mains at higher BPS and something like a 2uF snubber for the bridge. Every now and then when briefly pushing it to like 120VDC I'll see some 3ft or so arcs, and how consistent the swords are seems really dependent on the topload and breakout point. I want to play around with this arrangement to see if I can maybe hit about 4 ft arcs before going dual resonant.
