“Since Jimmy doesn't like to keep up his website, I thought I could host some of the pictures he often sends me of his DRSSTC work.” Ward's page gives the specification as Ward remembered it. The bridge is a full bridge of CM150 IGBTs (150 A, 600 V). The primary is 6 in wide aluminium flashing, for surface area. The tank is eight parallel strings of two 0.15 µF 2 kV CDE capacitors in series, 0.6 µF at 4 kV (“big cap!”). The mains is doubled to about 330 V DC, the secondary is 6.5 by 30 in of 28 AWG under a toroid about as wide, and a microcontroller acts as the VCO that drives the bridge. The glowing things in the base are light bulbs, there to show that the capacitor bank still holds energy. Maximum recorded spark 97 in; the pictures show about seven feet. The dates are his own, from his posts to the Tesla list: on the bench by 17 Mar 2003, 400 A pulses at 280 V on 17 Apr, CM150 bricks on 11 May, the first sparks of 6 in on 28 Jun, a 61 in strike on 15 Oct. Conner's FAQ edit of that December has 66 in at about 1.1 kW, “better than any OLTC to date”, and his October brick test was made after seeing this coil. Ward's own first DRSSTC followed in 2004.
Schematics and photos
photo: the coil, sparks to ground 
photo: the same evening, another strike 
photo: between bangs, the bulbs lit in the base 
photo: a long branched strike
Sources
- pupman.com: Jimmy Hynes, 29 Jun 2003 (first sparks)
- pupman.com: Jimmy Hynes, 15 Oct 2003 (61 in)
- Ward: Jimmy's Coils (the pictures and the specification)
- Internet Archive: scopeboy.com OLTC FAQ 1.0 (18 Dec 2003, the Hynes edit)
This is the card from the driver tree, written from what the builder published. Send corrections through the forum.