Rail Gun

[Pyromaniac1]

I am building a rail gun. I plan on using 3 400v 2200uf capacitors in series. Any suggestions on a supplier?

 

[GreenGiant]

Digikey? Mouser?
Should be a fairly common value.

 

[(*steve*)]

Look for capacitors with the highest ripple current rating you can.

Even better, look for capacitors designed to be used with xenon flash as they are designed to handle the huge discharge currents.

 

[Pyromaniac1]

Thanks. That was pretty helpful. Were kind of on a budget though. Do you think we could still get substantial power from 350 v capacitors, or only two 400 v capacitors?

 

[Pyromaniac1]

What kind of speed should the projectile be going when it enters the barrel to avoid spontaneous welding.

 

[Pyromaniac1]

How many 250 v 400 uf capacitors would i need to equal the power output of three 400 v 22000 uf.

Please give me any input you have so I don't melt my face off.

 

[jcurrie]

divide 22000 by 400. they will still have a 250volt rating though.
jc

 

[duke37]

The energy in a capacitor is C * V^2/2.
3 * 400 *400 * 22000E-6 /2 = 5280J

N * 250 *250 * 400E-6 /2 = 5280J
N = 5280 *2 /250/250/ 400E-6 = 422.4 say 420

This is all rather simplistic and the efficacy of the capacitors will depend on the resistances and inductances of the circuit.

 

[jcurrie]

Duke is correct I was thinking of farad not power.
jc

 

[Pyromaniac1]

Thanks guys. Fingers crossed I will not blow up my middle school.

 

[eKretz]

Don't say that...the NSA will send the black helicopters!