Personally, I'd steer well clear of furnace ignitors, you're talking big big danger with them, as the entire circuit is "hot". At least with the "standard" vehicle ignition, only the HT leads pose a significant danger (30kV or so with TCI coils). The disposable camera approach works, although it involves buggering about soldering wires onto capacitors that may or may not be ready to discharge enough "juice" to stop your heart as you work. I've been "bitten" more than once by flash caps, and it's never a pleasant experience. The other downside with the flash discharge approach is the time between sparks, as you have to recharge the capacitor off a small (usually 1.5v) source.Rocket Man wrote:Do you want an ignition system that runs on 120 VAC or battery???
For 120 VAC get a furnace ignition transformer off ebay about $15.
For battery idnition get a circuit board out of a throw away camera. Solder a wire on each side of the large black capacitor. Put aligator clips on the other ends of the wires so you can attach it to the spark plug. Solder a wire across the push to charge button so it stay on all the time. Remove the battery to turn it off.
The absolute simplest approach is a 12 car or motorcycle battery, a TCI coil, an HT lead, a spark plug, and some way of making a connect/disconnect on the 12v side (this can be as "complex" as an electric drill spinning a contact, a poor man's distributor if you like, as simple as a pair of wires that you touch / disconnect by hand, and anything inbetween). TCI coils are connected permanently to 12V, and a sparking is triggered when the juice is cut, collapsing the field in the primary coil. Most modern cars and motorcycles have TCI ignition, and the coils themselves shouldn't set you back more than $5 or so.