Dual Resonant Tesla coil II

Higher Voltages, Bigger Sparks

The Dual Resonant Solid State Tesla Coil (DRSSTC) is a slightly more complicated design and, as always with Tesla Coils stresses the electronics. This coil resonates around 80kHz. A full IGBT bridge circuit is used with a 340V DC bus with 'soft-start'. For safety it the controller is fibre linked.

Currently the primary MMC value is 233nF. This can be checked periodically as internal breakdown reduces the capacitance with time.

Other modifications were a redesigned flat primary coil to reduce strikes and a plastic shield with a grounded graphite edge cover over it. The secondary was also lifted from the coil by 30mm. This reduced the ground rail strikes and although reduced the coupling between the coils.

The whole coil has been built in a modular fashion, not only to allow easy packing for storage and transportation, but for ease of maintenance. All components are easily accessed for test or repair.

The coil has also been designed to run directly from the mains without the need for a Variac. An inrush protection circuit was required to be added. A neon lamp is added to show when operating. A series capacitive reactance is used rather than a resistor for inrush limiting. This prevents burning out a resistance in a fault condition.