Capacitor Bank

[armageddon11]

Hi.
I was just wandering as to how I would wire up a capacitor bank. I have searched all over the internet and have only found instructions that show how to make small ones with disposable cameras. I have recently bought a load of capacitors to make a capacitor bank which i could then connect to coil guns, rail guns and other high powered devices.

The main point is:
Do I need to put a diode / multiple diodes on the capacitor bank to prevent it discharging when I am charging it? i am worried that when the capacitors are charging, they will try to discharge back into the batteries (it is quite hard to explain.) Or can i just connect the wires to the capacitors and charge them straight up without any diodes or resistors or anything else.
Thanks in advance.

[wolfy9005]

You need a 1-way diode thingy(it only allows current to flow 1 way) from the battery into the capacitors. Then just hook em up(in series or parallel) depending on what you need it for(railgun/coilgun?)

[ETCS (Ret)]

The charging source of current (power supply) must feed the capacitor charge current through a diode with adequate voltage and current ratings. This is to prevent the capacitors from discharging back into the power supply.

Bear in mind that even a relatively small capacitor (20 microfarads) charged to just 100 volts will contain enough energy to be hazardous and can deliver a stunning shock should the wires be touched in such a way that it would discharge through the fingers or, worse, through both hands into the chest.

Capacitor banks will typically be several large capacitors parallel connected with a total capacitance of hundreds or thousands of microfarads. This amount of capacitance charged just to 100 volts would be lethal. Charged to 300 volts it would contain enough energy to be as hazardous as an explosive material.

Working with capacitor banks is exceedingly dangerous and one must be well educated in Electricity, Capacitive Discharge, and Safety Procedures. Never work on any high voltage, high capacitance system by yourself and always wear heavy insulated gloves anytime the capacitors are charged. Protective gogles are also a must since capacitive discharge currents can produce an effect as loud as a detonator cap when the capacitors are shorted, and metallic sparks will fly

Your original post would indicate that your education in Electricity is deficient. Please study and learn much more before you play around with these very dangerous and deadly devices. Seek the assistance of a trained electrican or electronics technican to guide and teach you.

[Zait]

Your original post would indicate that your education in Electricity is deficient. Please study and learn much more before you play around with these very dangerous and deadly devices. Seek the assistance of a trained electrican or electronics technican to guide and teach you.

And just in case you can't grasp that simple paragraph...

http://img262.imageshack.us/img262/6136/signelectricityla3.jpg

This is definitely a case of what you don't know can easily kill you.

[DyD]

The main point is:
Do I need to put a diode / multiple diodes on the capacitor bank to prevent it discharging when I am charging it? i am worried that when the capacitors are charging, they will try to discharge back into the batteries (it is quite hard to explain.)

Armageddon,
First - powerlabs.org
Second - the short answer is yes, you need a diode, but not to prevent charging the batteries. The capacitors can only be charged up to the difference in potential of the batteries, so there will be no current flow after they are fully charged.
The diode is needed so that when you discharge through a short circuit, the capacitors will not charge themselves in reverse. If you do not use a diode, you may damage your bank.