Modifying BBQ Ignitors

[paintball_playa]

" Please don't play with camera flash circuits!" - Joey

BINGO!!!! Not only are they sucky ignitions, but I have a bit of a horror story myself.

I wasn't taking proper safety precautions and I was just playing around with a camera flash circuit, and then I decided to quit, so I decided to disharge it. As you know the only way to do that is to place somehting metal across the contacts. Well I decided to do this with a knife I had nearby, but what I didn't realize is that I had part of my finger on the metal rivots holding the thing together. Big mistake. It shot both my arms out beside me faster than my eyes could pick up the difference, which means the electricity ran straight across my heart. Not good!!! I'm very lucky that didn't kill me right then right there.

Don't screw around with high voltage when you don't know what you're doing!!!

[utcpyro]

Well, I will say that camera flash systems are the cheapest, and give you the satisfaction of knowing that you made it. It's not much cheaper, but maybe by $3. You do need a coil to make it work half way decently, but you'll be rewarded with a spark twice as big as the stun guns I've played with.

Dump the capacitor into the coil with a button or relay, and then enjoy your nice spark.

Oh, and BTW, that charged capacitor MIGHT be able to kill you if it passes through your chest, so dont touch the flash circuit with both hands. That is what Joey was referring to. I've made "zapy things" for my brother's friends out of them (in a serious lapse of judgment), and it wont do more then hurt alot other wise. Now, the evil looking spudgun igniter on a stick things (my friends referred to it as a taser), those hurt like all heck and will light stuff on fire.

[cacophobia91]

I think that I will make my own ignition system just for fun. It doesnt sound like a very good first project though. What is the best way to get started with this kind of stuff?

Edit: I tried google and didnt find anything useful.

[Joey]

The safe thing to do is use either an ignition coil from a car or motorcycle (they are smaller). You have to find a way to pulse the current through the coil's primary.

http://www.geocities.com/CapeCanaveral/ ... oildrv.htm

http://www.powerlabs.org/igncoildrivers.htm

[staruiala]

Is it just me, or does 3-400 volts not seem like very much. A bbq lighter puts out 7000 volts and it doesn't hurt very much, and i have had many moments working with magneto systems on small engines (12-15000 volts) arc over my chest and no damage has been done, other than that great sensation of being punched in the chest. So Joey, i need your amazing electrical knowledge to tell me how much voltage will kill me, for I already know that Amps are freaking dangerous.

[DK]

Jason, Maybe I can help out with an answer.

You already know that amps are "freaking dangerous", but when you increase voltage using a transformer, there must be a corresponding decrease in amperage. A magneto carries 15000 volts, sure. A bbw igniter puts out 7000 volts. They are both at very low amperage, so they don't hurt much.

The flash circuit puts out 300-330 volts, but at a higher amperage than the bbq igniter. Amperage is a measure of the amount of electricity "flowing" through a line and an increase in amperage means an increase in the amount of electicity flowing in the line, and hence, is more dangerous. Think of it this way: Which hurts more, getting hit with a brick or 15 bricks at the same time? The single brick is the bbq igniter and the 15 are the flash circuit.

Jason, voltage doesn't kill (up to a point) but amperage does. You can get shocked several times by half-a-million volts of electricity and live happily (after some time later, heh) or die from a single exposure to the 30 amp draw you have in an ordinary household outlet.

If you're referring to a camera flash circuit (which is 300 volts) then no, it doesn't sound like much. But if you dump it into an ignition coil you get something like 27-30 000 volts.

I know you asked Joey this question, but I hope this helped anyway.

Cheers.

[Joey]

Great answer DK!

Let me add a few things.

When the camera circuit charges up the 330 volt capacitor, it loads that capacitor with several AMPS at 330 volts. When this capacitor unloads, it does it all at once, at the speed of light.

6 milliamps passing across your heart can be deadly, regardless of voltage. That is 6 1/1000ths of 1 AMP.

Higher voltages can be more dangerous because higher voltage lets the electrons travel through more resistance in order to reach earth (ground) this is why it takes a higher voltage to make an arc jump a sparkgap, and why a car battery doesn't shock you, even though its capable of delivering very high amperages.

A HV transformer capable of putting out 30-40 milliamps IS more dangerous than the 330v camera capacitor. But piezo ignitors and ignition coils don't put out much amperage, an ignition coil's amperage output is limited by the very fine wire that the coil is wound with. Don't get me wrong, an ignition coil shock is quite a zap, and very uncomfortable, but you would have to be pretty intent on doing yourself in to be killed by one.

This is made pretty obvious when you short out the camera flash's capacitor. It makes a loud "POW" sounding like a firecracker, compared to the ignition coils quiet "tic".


Do some reading Everything DK and I have said is vastly oversimplified, but there are plenty of places on the net with thorough explanations of electrical theory.

[staruiala]

Thanks for the great explinations guys. I just didn't reallize how greater the amps were in the flash circut, but it all makes sense now.

Just remember - Volts Jolts, amps are [intercourse]ing dangerous

[markfh11q]

I believe you mean, "Volts schmolts....";)

[staruiala]

sorry, thanks