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How long can i get a charge from a capacitor? Answered

I am working on another rocket ignition system and i want to use a capacitor instead of 8 double a batteries. I need about 12 to 15 volts sustained over 5 seconds. Could this work?


I think you could use a disposable cameras flash circuit .

Maybe. The time it takes a capacitor to charge/discharge depends on it's capacitance and the resistance in the circuit along with it. Basically, you want the resistance of the line multiplied by your capacitance to equal 5 (for 5 seconds). If current is not an issue then just find the biggest capacitor you can and add resistors to match it to 5 seconds. If current is an issue (I expect it is) then I'd just stick with the batteries. I used to launch rockets, and my launcher was made with one 9V battery. It worked very well.

Ok, thanks for the input and wow, 9 volt? i cant get squat out of those

Yeah, it worked for me. I guess it could depend on the ignitor. I just used some cheap little ones that were sold at my local hobby store.