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Need Advice for Building a Capacitor Bank

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Atomizer

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I am trying to build a capacitor bank and charger using 330v 120uf photoflash capacitors and their chargers, which will be used to power a coilgun. I think that my design should work, but I'd like to see if anyone can come up with improvements or point out a problem.

For the charger, I plan to connect 6 photoflash charging circuits in parallel on the capacitor end, and in series with a 9v battery on the input end. This should provide 1.5v to each of the circuits and charge the capacitors at 6x the speed. To turn on/off the charger, I will place a simple toggle switch between the battery and the chargers.

For the capacitor bank, I plan to connect around 20 (possibly less) 330v 120uf capacitors in parallel and attach them to the chargers, which are already connected together in parallel. to open the bank for discharging, a large switch designed to be mounted in a wall will be used. The actual discharge will be triggered by a microswitch inside the coilgun, which will close when the projectile, a ~1cm diameter ball bearing, enters the barrel and presses the switch.

The coilgun will be built using 300ft to 500ft of 22 guage magnet wire wound around a PVC pipe - I think this specific wire should withstand the current/voltage, but I'd like an opinion on that here. Also, I've read that a diode somewhere in the circuit can extend the life of the capacitors and partially recharge them, but I have no idea what to do with this - I saw some diodes on the charging circuits, so I may not even need this. Any suggestions?
 
Your charging will be limited mostly by how much energy the battery can be coaxed to deliver. A 9V battery is a very bad choice in this regard. A much better choice is an individual 1.5V AA battery on each flash unit. Or you could power all flash units in parallel on a 1.5V D cell.

The flash units will not like to be wired in series, because their active circuits will interfere with one another. And the flash chargers probably have a common wire between input and output so connecting the common outputs together would short all the inputs.
 
Ok, I'll switch to using a 1.5v D-cell in parallel in that case - but what is the problem with connecting the outputs in parallel? If I can't connect them that way, how else can I decrease the charge time for the capacitors?
 
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