SSTC Half Bridge 120vac (CW/Interrupted/Staccato)

SSTC 5 circuit with CT feedback and I wound a new coil of 32 AWG for it.

When I'm finally done with this it will be half wave/full wave/filtered/unfiltered/staccato/interrupted w/midi input. I need to figure out the exact science but you can make some pretty good bass running unfiltered interrupted by increasing the on time high enough. This doesn't work well filtered because the arcs make more of a bang.
I'm gonna make another staccato circuit and just put it on board since this will be straight 120VAC driven, and hopefully get longer arcs with bigger topload and a bit of phase tuning. I'm working on another SSTC I made a clean board and layout for but I added a voltage doubler to it so I can't run it unfiltered or really run CW at desirable power levels. That would be more for reliable interrupted output with decent arc length I could probably play music reliably from and be able to get really low bass frequencies or really high tweeter frequencies a DRSSTC might struggle with.

I should have left the old on board TL494 interrupter because it makes CW mode easy. Otherwise I'm flipping on a switch to tie the enable pins to V+ and it may not always work. Ramping the duty up to 100% during oscillation keeps a steady filtered CW going each time. The other solution is an on board oscillator that sends an enable pulse at roughly the same frequency as the coil, always ensuring feedback during CW modes. Unfiltered CW is probably the coolest but at the moment I'd have to do something like keep the circuit oscillating using an external pulse from a small Slayer exciter unless I run semi-CW by keep the duty just under 100%. I can make a weaker looking unfiltered fake CW by messing with the interrupter enough.

This setup will have a couple swappable primaries. The other is of the same turns but more condensed together and allows me to run full CW and pull the hot arcs at low power but does not provide the longest interrupted arcs. I can pull some wicked arcs from a fat bush only feeling a slight hum in the variac, whereas with the other primary it starts rumbling at about 70VAC and would require a lot more amps just to get the same bush. That higher amp draw with that primary is what helps get the longer arcs but it switches the fets a lot harder so long term CW is not ideal with it.

With most SSTC's it's also easy to bypass the feedback and just run a fixed frequency to the gate driver inputs as opposed to the enable pins. This could make it so you could drive a flyback from the bridge for example.

[RAVI]

What you've got there is very nice. Once again, great video & nicely done.

[RAVI]

That's pretty beefy arcs that you've got by moving that lamp close to that top load! Well, for the interrupter, did you use the one with the three triple 5 timers including the burst mode? Or did you do sort of hybrid with that interrupter by adding your famous TL494 PWM also? I think that your famous Tl 494 would have also worked fine. Maybe you should swap your other interrupters too into that circuit & give them a try & see if there's a big deal of differences with the output.

[Jonodrew]

Pretty meaty arcs especially for a half bridge circuit - and with a broad frequency range there a schematic available for SSTC V5?