Hai, Mjollnir conquered your chair. RF burnz plz

This part of my site describes the work I am doing on the Dual Resonant Solid-State Tesla Coil (DRSSTC). I was mainly interested in trying out new driver circuits, and to this end I built a small cute-looking demonstration coil (pictured above) controlled by a Phase-Locked Loop. It turned out a great success: DRSSTCs are famous for blowing out their transistors, but this coil hasn't blown a single one to date, in spite of being cranked way over the original design limits.

I called it "Mjollnir" because it's slightly less cliched than the usual "Thor" or "Odin". Recently, I found this quote in the Wikipedia article on Mjolnir:

"...He(Thor) would be able to strike as firmly as he wanted, whatever his aim, and the hammer would never fail..."

So I reckon that counts as a good omen :-) Mjollnir went on to get hooked up to a Roland synth, which proved very popular on YouTube and the geekblogosphere. Finn Hammer and I then built six scaled-up versions of it, and performed some Bach and a cover version of Hard Rock Hallelujah. Many other musical DRSSTCs have been built since, but we claim ours is the original and has a slightly less horrendous tone than the rest! ;-)

Mjollnir also spawned Odin The All-Fragger, a giant scaled-up version powered by brick IGBTs, similar to Steve Ward's largest DRSSTC. Odin had to be mothballed due to lack of time and resources, but the project may now have found a sponsor who could make it bigger and better than ever! It's early days yet, but stay tuned! Latest news on Odin at 4hv.org

For more DRSSTC information, check out these other great sites-
Steve Ward operates the world's most powerful DRSSTC
Jimmy Hynes made the first ever
DRSSTC.COM by Terry Fritz
Dan McCauley another DRSSTC pioneer

Initial messing around
DRSSTC modelling
Further experimental work
Testing the new PLL driver
Testing with single resonator
Testing with dual resonators
The Mk2 PLL driver and accessories
Please read the PLL system docs for explanations of how these circuits work. PCBs were available to buy for a while, but are currently out of stock. The schematics below show what's in the "Mjöllnir" DRSSTC.
Driver board schematic sheet 1
Driver board schematic sheet 2
Driver board schematic sheet 3
Dee-Lux Interrupter schematic
"Solid-state variac" board schematic
H-bridge, current sensor, and SCR regulator schematic
EAGLE board and schematic files + BOM (115k zip)
After building Mjöllnir I revised the PLL driver board and designed an IGBT brick driver add-on for Odin The All-Fragger. WARNING: this has never been fully tested yet! for reference only!
EAGLE board and schematic files for Rev. B
IGBT brick driver schematic
Brick driver power supply schematic
Docs for PLL system Rev.B (123k PDF)
Building Mjöllnir* the experimental coil
Primary coil and current sensor
Secondary coil and driver board
H-bridge
The build continues
Appearance at Derby 2005 (links to roffesoft.com)
Primary needs modifying
Appearance at Cambridge 2005 (links to roffesoft.com)
5ft spark at Cambridge 2005
Spark pictures
First light, flashovers
More sparks
Experiments
Bang capture with DSO
Efficiency experiment 1
I start work on Odin The All-Fragger
Prototype IGBT brick driver
Read more about O.T.A.F. on 4hv.org...

*Mjöllnir was the name of Thor's hammer that he used to forge lightning bolts (afaik)
So it's almost like calling your coil Thor but not so cliched.
I think I'll call the next one "Odin The All-Fragger"