Steve Ward SSTC-4: a Marx-supplied SSTC

A different way to get voltage than a simple H-bridge. Stacked half-bridges have capacitors that charge in parallel and discharge in series, “all of the supply capacitors are in series, like in a Marx generator,” which roughly doubles what a plain full bridge could deliver. Two opposing 2-stage inverters give about 1600 V peak-to-peak from a 400 V DC input. In March 2004 it was simplified from an original 4-stage design down to 8 MOSFETs total to cut cost. The redesign reached about 24 in of spark in January 2004, and then the project stopped. Ward’s own page marks it discontinued in favour of DRSSTC. The schematic images the page references no longer load, and no other copy has turned up.

Schematics and photos

Sources

• SSTC-4
• pupman.com: Dan McCauley, Needed: SSTC History and Achievements (8 Jun 2004)

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