coil gun capacitor help

[Chriszz11]

I am builing a coilgun, and was looking into getting more powerful capacitors. i am using a normal photoflash charger, and 10 parallel wired flach capacitors. The capacitors i was looking into getting, are from radioshack, 1000uf 35v or 50v. Would my flash charger still work with these capacitors, or would i need to get a new charger? also if i get ten of these and wire them together, it would still have 10000uf and 350v right? that could come to 1250J energy stored.

[TonyMcC]

The capacitors i was looking into getting, are from radioshack, 1000uf 35v or 50v. Would my flash charger still work with these capacitors, or would i need to get a new charger? also if i get ten of these and wire them together, it would still have 10000uf and 350v right? that could come to 1250J energy stored.

You can have 10000uF with a working voltage of 35V (parallel connection) OR 100uF with a working voltage of 350V (series connection). You can't have it both ways!

[Chriszz11]

oh my appologies. i am a little new to this. the bank i am using now is made of 10 330v 120uF caps. and i charge it to 600v. what would you recommend that i do?

[Chriszz11]

i just built a new capacitor bank, out of 18 photoflash capacitors. I lost some power from the gun. Could anyone tell me why that happened, and how i could fix that problem? Would increasing the coil wire size help?

[lightning diety]

there is a video on instructables.com at http://www.instructables.com/pages/search/search.jsp?cx=partner-pub-1783560022203827%3Anpr2q7v5m6t&cof=FORID%3A11&ie=ISO-8859-1&q=coil+gun, this website is great because it can help with a lot of projects in any number of fields

[Enthalpy]

First, put a string of resistors in parallel with your capacitors if you connect them in series, so the resistors will share the voltage equally, or it's guaranteed to end in a bang.

 

Then, you need something to discharge the capacitors automatically, for safety. Don't forget that chemical capacitors have a memory effect: some charge (like 10% of the voltage) reappears slowly after you discharged them and open the circuit.

 

And finally, you should have a look at the energy and capacitor size needed to make even a miniature coil gun.

[Lance]

i just built a new capacitor bank, out of 18 photoflash capacitors. I lost some power from the gun. Could anyone tell me why that happened, and how i could fix that problem? Would increasing the coil wire size help?

 

The discharge time was too high. Thicker wire, more voltage, or less capacitance.