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Could i use an ignition coil and breaker points to fire a coil gun? Answered

I've made one of the basic models i've seen around here, but i was wondering if i could skip most of the painstaking soldering that i suck at, and use car parts. I'd still be soldering here and there, but not tiny camera circut boards. I'm not retarded, i am aware of the high volts at work on spark plugs, so spare me me the "you'll shoot your eye out" type lectures, already tasted that flavor. But would the automotive coil even charge if it is shorted across by the barrel coil? i know breaker type ignitions dont fire till the power source is cut by opening the breaker. but a spark plug is an open circut and i'm not sure if a coil pack will charge if that circut is closed.




10 years ago

Ignition coils don't "charge". They're not capacitors, they're transformers. You put 12vdc across the primary, and when you abruptly cut it, the current collapses and there is a high-voltage, low-current pulse from the secondary to the ground (or the 12v, for that matter). For a coilgun, it is useless. what you need is a low-voltage (~350V), high-current pulse. For, that, you need caps. But, you don't need to solder tiny camera circuit boards to charge caps. Feed them 350VDC through a limiting resistor and you're done. For the PSU, you could get away with something as simple as a step-up transformer and rectifier bridge. The camera circuits are just designed so the 350V comes from a 1.5V battery, so that it is more convenient on a hand-held coilgun. But if it is for a desktop model, who cares? charge it from the mains with a variac, some diodes, and a resistor. It will be faster, and less soldering hassle.