Capacitor charging circuit

[WilliamN]

Does anyone have any good ideas for building a capacitor charging circuit for a coil gun. I thought about using a 555 timer with a PNP/NPN transistor amp feeding pulses to a step up transformer charging 3 big electrolytic capacitors that are wired in parallel. Space is not an issue so if there is anyone who has better desgins let me know. I want to use 12Vdc.

 

[Nigel Goodwin]

Does anyone have any good ideas for building a capacitor charging circuit for a coil gun. I thought about using a 555 timer with a PNP/NPN transistor amp feeding pulses to a step up transformer charging 3 big electrolytic capacitors that are wired in parallel. Space is not an issue so if there is anyone who has better desgins let me know. I want to use 12Vdc.

You don't mention any specs you need, but have you considered using a cheap flash gun, or the flash components out of a cheap disposable camera?. They are not 12V though!.

 

[Russlk]

What do you mean by "coil gun"? Do you intend to accelerate a missile using magnetic repulsion? Dumping a large capacitor into the coil could produce spectacular results, but the switch will have to carry lots of current. I don't see why you need a timer unless there are more than one coil.

 

[laroche73]

Coil gun

This site has some very detailed information on coil gun construction: https://www.pskovinfo.ru/coilgun/indexe.htm

 

[WilliamN]

I suggested the 555 not for timing purposes, but as an oscillator to charge a large capacitor to 500v. I want to use a 12v supply voltage then bump it up to 300v. I am using a disposable camera unit now with a diff capacitor(bigger) soldered in place of the original. This works but I would like to build my own power supply. Thats what I was asking for, a circuit similar to the photoflash charger. Basically I just need a 12v to 300v power supply. My capacitor bank will be (3) 400uf 500v capacitors wired in parallel. So I am looking for a circuit that will charge them relatively quickly.