What is the best way to charge these capacitors?

[GageThamert]

Ok, so I need to "charge up" 8 560UF, 250 Volt DC capacitors. I would prefer to be able to charge them in series, as I am going to use them to construct a rather small capacitor bank. Any suggestions?

Thanks!

 

[NobodySpecial]

Any suggestions?

Don't
Sorry but if you are asking such elementary questions about a possibly dangerous item we aren't about to help you build the rail gun or whatever.

 

[GageThamert]

I know how capacitors work and I have used them many times, I have just never used them outside of a circuit in this way and I was wondering if there was anything special I would have to do. I am pretty sure I have the knowledge necessary, my thinking was that I might as well ask to be safe.

 

[berkeman]

I know how capacitors work and I have used them many times, I have just never used them outside of a circuit in this way and I was wondering if there was anything special I would have to do. I am pretty sure I have the knowledge necessary, my thinking was that I might as well ask to be safe.

What are you going to do with this capacitor bank? How will they be discharged.

And you can't charge capacitors in series...

 

[GageThamert]

they will be discharged wired in series and discharged all at once by means of a large single pole switch. they will be powering a "coin shrinker."

 

[berkeman]

they will be discharged wired in series and discharged all at once by means of a large single pole switch. they will be powering a "coin shrinker."

Why do you need 2kV to smash a coin?

 

[schip666!]

Of course you can charge capacitors in series, but you'll have a 70uf (560/8) 2000v capacitor. Is that what you want? Or do you want to kill yourself with a lower voltage and much higher current by putting them in parallel?

In any case the issues are about the same. You need to slightly current limit the input because laying 4480uf (in parallel) across a power-supply will look like a dead short for a moment. And you need to put a bleeder resistor across the whole bank so it will self-discharge in a reasonably short time after the power is removed.

Also your switch better be able to handle a goodly current without arching and welding itself in the ON position. Maybe something like an electrical service entrance contactor.

 

[berkeman]

Of course you can charge capacitors in series, but you'll have a 70uf (560/8) 2000v capacitor. Is that what you want?

I suppose you can charge them in series, if you use the bleed resistors to balance the voltages. But as you say, it seems weird to series connect a capacitor bank. I haven't worked with them very much, and any time I did, they were parallel connected.

BTW, I just Googled capacitor bank, and every other entry had the word "dangerous" in it. I'm not real comfortable helping someone design a 2kV capacitor bank for "smashing" applications -- too much like some of the Google hits. Sorry, thread closed.