Atomizer

If I had taken the capacitor from a camera, I would have done that, but what I am asking is exactly HOW I can build a charging circuit from scratch if the capacitor did not have one originally, preferably to charge from a 9v battery.

Thanks for the advice, but I have two more questions now: 1) If I wanted to charge the capacitor to full power, how would I do it? And is it possible to do this using a small battery like a 9 volt? I've stubled upon a lot of pages explaining how to use the capacitor (300v) and charging circuit of a disposable camera to charge from a small battery, but nothing about building the actual "capacitor charging citrcuit" from scratch. 2) Do you have any thoughts about my method of triggering the coilgun using the steel projectile itself as part of the switch? Would this be a reliable method of triggering the gun?

1) So how do I connect the LED to let me know when the capacitor is charged? 2) I am aware of this (as explained in my post), but how else should I charge it? What kind of a circuit would a battery of low voltage need to charge a high voltage capacitor? 3) As explained above, the coilgun needs to give the ball a substantial speed boost, but not enough to cause it to fly off the styrofoam track.

I am trying to build a coilgun for a school project. Its purpose will be to accelerate a ~1cm steel ball as it travels down a ~2.5cm semicircular styrofoam track running through the coilgun. The coilgun itself will consist of several turns of magnet wire around a PVC pipe fitting over the track. I have created a preliminary design, though I have several concerns about it: The switch on the battery-capacitor circuit controls the battery's connection the the capacitor, and the LED indicates when charging is complete. The gray slip just in front of the ball is aluminum foil, the gun should fire when the steel ball rolls over the foil on the bottom and brushes an identical piece on top. Here are my concerns: 1) I don't think that I am connecting the battery to the capacitor correctly. As I recall reading somewhere, the 9 volt battery should only be able to charge the capacitor to 9 volts. How should I connect the 9 volt battery to charge the capacitor fully? 2) I think that the capacitor may be too powerful and cause the ball to leave the track - am I correct or is this enough to only somewhat accelerate the ball, not fire it at dangerous velocities? If the capacitor is too powerful, should I try instead using multiple 9v batteries, and extending the aluminum foil trigger ~1/3 of the way into the barrel to keep it on the correct length of time? Also, if I use multiple 9v batteries, should I connect them in parallel (more current) or in series (more voltage) for maximum effectiveness? 3) I'm not sure if the aluminum foil switch is the best idea for this. I was thinking of using the microswitch shown here: http://www.coilgun.eclipse.co.uk/coilgun_basics_2.html, but I would need to extend the lever inside the coil. So is my current aluminum foil switch the best option, or is there a better solution to activate the coilgun without a manual switch? I would very much appreciate it if someone would help me find an optimum design for my coilgun.