Instructables

need help with capacitor charger

I am new to this so please excuse my stupidity. I want to make a capacitor charger (for a small coil gun) I know there are instructables about them but they are all with chargers that came from a camera which I really don't want to do because i would like to make my own circuit that i can play around with and not blow it up by accident. If someone has a link to a project like this please post if not i have another question. Could I just take let's say a camera that has an 80uF 330v cap and switch it with a parallel bank that has 5 or more 220uF 25v caps or something larger. Would that work or would that blow the circuit or would it be better to buy the same caps as the camera and hook them together. Thanks

RetroPlayer5 years ago
Wow... I hope you realize exactly how dangerous this is. If you are not familiar with electronics, I would not suggest something like this as a first project. I will answer your questions only generically. If you wire 25V caps in parallel and supply more than 25V to them, they will explode! Wiring them in parallel will increase their capacitance as lemonie noted, but not their voltage level. When choosing a capacitor, always make the voltage rating around twice the voltage you are going to supply to it. A camera flash circuit will be at least 200V, if I remember correctly. And please... don't do any of the things junits15 suggested (no offense junits.) To answer your question, more specifically: a capacitor charger circuit works by using a step up transformer. But transformers do not work with DC, so you need to create an oscillator that will pulse the voltage into the transformer. Then you will need a capactior on the other side to smooth it out and a half-wave rectifier to convert it to DC. Then you limit the current with a resistor going to the capacitor bank to charge them at the higher voltage. If that sounds wildly complicated, then I would definitely suggest NOT trying something like this until you understand what you are doing better. This project could easily burn you, blind you, dismember you, or even kill you. And that is before you even load the projectile.
lemonie5 years ago
5 x 220uF will give you 1.1 mF. At 25v you'll store 27.5 x 10-3 C. If you discharged this in 1/100 of a second you'd get 2.75 A. For a coil gun I think you're going to need a lot more capacity.

L
junits155 years ago
do this, buy a 300V bridge rictifier and a wall plug, buy a cap that corrisponds to the voltage comming ouy of the wall, ex: I live in the US so I would buy a 120V cap. put the bridge rectifer on the wall plugh and use it to charge the cap. be EXTREMELY CAREFUL WITH THIS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! once you change the ac to DC it becomes way more dangerous.
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!