A student-club build (signed on the schematic by @kentomm565) with one clever trick. The IR2104 is a half-bridge gate driver, but here it is wired as two independent low-side outputs, by tying the shutdown pins together and driving them from a separate control circuit: “despite being a half-bridge driver, wired as a dual low-side gate driver by skilfully using the shutdown pin.” It replaced an earlier NAND-gate control circuit, for simpler wiring and more stable operation. It drives 2MBI200VH-120-50 IGBT modules in a full bridge through a GDT. The hand-drawn schematic is easy to read, colour-coded into control circuit, gate driver and full bridge sections. The same person (handle later shortened from kentamu to kentam) also wrote the club's GDT design guide. It finds the resonant frequency by sweeping the oscillator for peak amplitude rather than relying on calculation alone.
Schematics and photos
DRSSTC schematic: control / gate driver / full bridge (hand-drawn)
Sources
This is the card from the driver tree, written from what the builder published. Send corrections through the forum.