Introduction
Due to the experience acquired in the DRSSTC III large tesla coil project, in 2021 I decided to improve it. Meet DRSSTC IV
Specifications
- Driver: DDRX by Franzoli Electronics, based on Steve Ward’s UD2 (includes phase-lead, overcurrent detection, undervoltage-lockout, tOn limiter, DTC limiter and overtemperature protection)
- Power Supply: 3-phase voltage doubler with automatic pre-charge by Franzoli Electronics, 220V(AC)in, 620V(DC)out, up to 11kW
- Bridge: CM300DY-24NF IGBT’s Full-Bridge
- DC BUS: Laminated, splitted in half, 2mm thick aluminum plate. 1kV | 6mF (4x 500V | 6mF electrolytic capacitors, 2s2p) BUS capacitor bank, 1.1kV | 80uF (2x 1.1kV | 40uF film capacitors, 2p) decoupling capacitors
- Resonant capacitor: 12kVDC | 0.68uF (36x 2kVDC | 0.68uF film capacitors, 6s6p) resonant capacitor bank, 168ARMS rating
- Primary coil: Flat, oil cooled, 10 turns of 3/8″ copper pipe, tap at 8.2 turns, 1/2″ aluminium tubing strike ring, covered by 5mm thick acrylic plate
- Secondary coil: ~2400 turns, 250x1100mm PVC form, 1070mm winding, 26AWG. Polyurethane and epoxy coated
- Top load: 1120x275mm skeleton toroid, 13x 1/2″ aluminium tube rings, 3D printed frame
- OCD: Set at 1kA
- CTs: 2x 1:40:25 = 1:1000 cascade, same ratio for OCD and feedback
- Resonant frequency: 34.96kHz (primary)
- On-time: Limited at ~600us
- Duty-Cycle: Limited at ~16%
- Thermal protection: NTC thermistor, schmitt-triggered 9ºC hysteresis On/Off control (55/41°C)
- Enclosure: 410x410x295 (mm), 20mm T-slot aluminium profiles + 5mm thick acrylic plates.
- Height: 207cm
- Streamer lenght: Up to 3.60m, measured in a straight line.
