Dual Primary SSTC

Dual Primary SSTC

Introduction

For about a year now, I've been thinking about trying a paralleled primary approach to the SSTC coil. Although paralleled primaries

electrically may be equivalent to a primary with decreased turns, the use of multiple SSTC drivers removes excess stress off the individual

switching circuits and allows you to run at higher power levels with greater reliability.

For this initial experiment, I used two PlasmaSonic I SSTCs configured in single-ended mode and run with 240VAC half-rectified input.

I used a single TL494 timing circuit to control both SSTCs. This would allow almost synchronized operation. Results were outstanding.

I was easily hitting the 26" mark and the arcs were much thicker and nastier than what I was used to. Due to the small coil being used

for this particular experiment, I was running the drive frequency a bit high for my tastes at around 400kHz. FETs were getting quite

warm as i'm sure the gate drive signals were probably starting to look pretty bad.

I eventually plan on using four individual primary circuits, although I will use a larger secondary for this.

Dual Primary SSTC block diagram.

Last modified August 16, 2005 08:05:20 PM