Camera Flash Ignition Question Thread

[DK]

rmich:

I just looked at your diagram, and the setup looks fine. A slight alteration is not to remove the flash bulb but keep the setup the same. This would give the circuit a chance to discharge through the flash bulb if your spark gap is set too far apart. I wrote that article in the wiki and made the pictures, so feel free to e-mail/private message me if you have any wiring problems.

About pyrogeek's comment, i have no idea what that would do to the flash circuit and you can try it for an experiment. And no, the capacitor would not shock you after being dunked in the water. Water's conductive, and would short the cap out completely.

Don't worry about the number of questions, it's why this forum is here. Some words of advice for this system though: have a few disposable flash cameras on hand when you do this since you're going to fry some. At least until you get the hang of it.

[noname]

"s there any chance that the camera will retain the charge in the capacitor, and would be able to shock me even after it was dunked in the water?"
Try it and hope for the best. Come on man, it's only a little 330 volt "buzz!"

[Velocity]

Thanks for the responses. Another question I have is do I need some type of "rated" switches and other electrical components? Obviously I need some really heavy duty wire running from the ignition coil (wouldn't it make 300,000+ volts?), but would I need special switches or anything else for other parts of the circuit?

If anyone has a link to a good relay that I could pick up from radio shack, it would be greatly appreciated .

BTW, great article you wrote DK

[DK]

Thanks rmich.

You shouldn't need anything better than a couple of momentary switches from radioshack. The relay isolates the flash circuit from the trigger switch so you'll need a switch that'll carry 12 volts @ 1 amp. The ignition coil isn't 100% effective, so if it has 100:1 windings it'll produce something like 27,000-29,000 volts from the 300volt capacitor in the flash circuit. A short answer to your question: no special switches are needed.

As for the relay, a standard 5-pin automotive relay is your best bet. They cost five bucks (CAD) and you can get one from any automotive store. Chances are, Radio Shack'll have them too (if it's a good store, they'll also have the socket it goes into, like this one).

I would use 12 or 14 gauge wire for the ignition coil. This'll give a good flow and have enough insulation to keep you from getting shocked.

Have fun wiring this, and remember to use a big project box. There get to be a lot of wires in a small space, so be careful with shorts. Also, electrical quick disconnects such as male/female spade connectors are a good thing to have set up at key locations in the wiring. If you short the flash circuit out, they can make it less of a pain in the ass to fix the cannon.

[TurboSuper]

There's a very simple and 100% accurate way of knowing if the cap is holding a charge- Multimeter.