Hossein Naderi's DRSSTC II: a half-bridge driver with discrete totem poles

The same builder as the PLL SSTC in the SSTC tab. This is his first large dual-resonant coil, posted to High Voltage Forum as the whole KiCad project rather than a write-up. His name is on the board: the silkscreen reads “DRSSTC v2, Hossein Naderi”. Three sheets, revision 2, dated 14 February 2026. The control sheet puts an adjustable phase-lead inductor on the feedback current transformer and uses an LT1016 comparator, annotated on the drawing as what “sets noise immunity”. A separate overcurrent CT goes into an LM311 with its own trim. Two 74HC74 latches hold OCD_STATUS and IS_RUNNING, so a trip stays tripped until it is cleared. The output stage does not use a single driver chip. Two TC4427s each feed a discrete complementary totem pole of IRFU9024N and IRFU024NPBF, into two separate gate-drive transformers, and a jumper chooses which drive signal goes to which. Undervoltage lockout is a one-part change. The sheet notes “Z8.2 for ~12V UVLO, Z20 for ~22V UVLO”. The bridge photographed beside it is a half-bridge brick on copper busbar with Alcon KP-3C snubbers, and a hand-built MMC of KP-6 0.22 µF/3000 V cans stacked above.

Schematics and photos

Sources

• highvoltageforum.net: hnaderi’s first large DRSSTC

This is the card from the driver tree, written from what the builder published. Send corrections through the forum.