Solid State Tesla Coils

Current Projects:

New DRSSTC Driver

DRSSTC Interrupter with Burst Mode

DRSSTC Design Guide

DRSSTC Magnifier-2

DRSSTC Magnifier-1






Related Information:

DRSSTC: Magnifier vs. 2-coil System

DRSSTC log book

Jimmy's Coils

Old Projects:


SSTC-1 (Half-Bridge)

SSTC-2 (Full-Bridge)

SSTC-3 (Twin System)

SSTC-4 (Marx-Based Full-Bridge Design)

SSTC-5 (Mini SSTC)

SSTC-6 ("Micro" SSTC)



Some SSTC basics to introduce them.  Solid State Tesla Coils, in their earlier stage (see my "Old Projects") were basically just a power amplifier driving a secondary coil at resonance.  The most common method for switching power into the resonator is a half-bridge or full-bridge of transistors (typically MOSFETs or IGBTs for their high power capabilities).  Basically, line voltage is rectified (and sometimes filtered) to get a DC power supply of a few hundred volts.  This DC is then fed into the bridge and comes out as an AC square wave into the TC's primary coil.  Switching frequency can be determined by a simple oscillator, or by using feedback from the secondary coil itself.  I have always preferred the later method as no tuning is required. 

From here the DRSSTC was developed.  The idea is to make not only the secondary a tuned circuit, but to also have a tuned primary circuit.  There are 2 great advantages here.  Firstly, resonant voltage rise allows us to achieve several kilovolts on the primary coil, which gives a much better impedance match to the secondary resonator.  Also, by the fact that there is a greater voltage across the tank circuit, this implies that the current must also be much greater to support this voltage.  A typical DRSSTC running around 1kw of input power might generate around 6kv and 600amps, peak, within the tank circuit.  To keep the H-bridge from failing during these stressful conditions, we operate the coil in "bursts" of RF.  A typical burst may last 200us, and transfer 10J or so into the secondary coil during this period.  Duty cycles are typically less than 5%.  It is important to mention that IGBTs must be used to handle these great currents.  IGBTs do not have an ON-state resistance, rather they have a voltage drop, similar to a diode.  IGBTs generally are much better for high current applications where I*I*R losses would burn up most MOSFETs.