I'm just starting a project that I've been thinking about for quite some time. i would like to make a coil gun. my question is this: what would be the best method of multiplying the voltage from, say, two 9V batteries up to an amount fit for charging four 400V 6300uf capacitors. i don't want anything too big like a dc/dc converter but something that i can assimilate into the coil gun design. And considering my laughable experience with circuits (about two courses of electrical classes) do any of you have resources for me to learn how to design and make the multiplier that i need?