Instructables

i need help with a charger circuit for a capacitor bank.

i need this for a 720v 1500uf capacitor bank. I want it to charge with a maximum time of 10 seconds, and it must have an input voltage of 1.5- 12v. I DO NOT want to use camera charger circuits. thanks allot! -biolethal

Xellers5 years ago
The best bet is to use a computer PSU's 12 VDC output through a high current oscillator and then through a step up transformer. After that, you convert it to DC and charge the capacitor. If you need me to, I think that I might be able to invent a schematic for this.
biolethal (author)  Xellers5 years ago
a shematic would be great! thanks for the reply! -Biolethal
I don't know if I will have enough time for this in the near future, but you basically need an Armstrong Oscillator or something controlled by a TL494 to switch through a small transformer. Then, you rectify the output and feed it to the capacitor. The transformer is the hardest part. You might even need to wind your own, or you could modify one and use a voltage multiplier to acheive the correct voltage.
Xellers Xellers5 years ago
I really have too much schoolwork to draw schematics at this point - Sorry. Here is something along the lines of what you need: http://stevehv.4hv.org/12kwPFC.htm. That is far more complicated than you need , but it is an example. You really don't want to have 10amps at 800 volts DC on your average workbench - it will kill you given the chance. Another option that you could use is a MOT with a voltage divider. You will need high power parts, and there will be lots of wasted energy to lower the voltage, but it will work.
biolethal (author)  Xellers4 years ago
maybe i could use a much larger version (12v input, 2-3 large toroids etc...) of the joule thief to make a higher voltage?
Quite honestly, I doubt it. The voltage gain is not that significant. Try some sort of electronic oscillator driven transformer.