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Can I charge multiple capacitors without a DIY DC/DC converter? Answered

I'm starting to build the coilgun in rwilsford07's instructable but he says that camera circuits are very ineffecient and to try a DC/DC converter like in his other instructable but I'm hesitent to build it because it uses a wallplug to draw power from the mains and if something goes wrong I'm a dead man. So I'm wondering if there's a way to quickly charge the capacitors using car batteries (which I've got several of) or with an even larger capacitor (I've got a 2100v AC capacitor) Or would it be easier to buy somethng to suit?


i really like this insturctable and like most of his guides there really well written. make sure to check out the 500v dc-dc boost converter!! i built it and it works great.....this one doent draw power from mais supply just be carfull when working with high voltages. hope this helps :)

what voltage do you want? BTW mains should be the least of your worries, BAM, high voltage capacitor charged to a high voltage ready to strike and deliver thousands of amps into your body, and the capacitor wouldn't even flinch. Also, someone explain this to me, isn't it technically imposible to kill yourself from the 120vac mains? Isn't the body's resistance too high (and for some reason I keep spelling high "hgih") to allow enough current (20mA) through in normal situations? BTW being soaked with water is not a normal situation.

Nope. Electrons can penetrate the skin at around 55 volts (+/- 10). 120 Volts is more than enough to kill you, if it goes across any vital organs. I did see this one time when someone killed themselves with a multimeter. He stabbed the leads into his arms to show how the body's resistance decreases exponentially as soon as the skin is out of the way. Obviously he wasn't trying to kill himself, but I guess he underestimated.

it depends on the path and time the current flows if the path is thru your head / heart / neck etc and it gets thru your skin you can get killed if you touch anything with the back of your hand youll srike away quickly and its less likely that somthing happens if there is rcd in the circuit it'll usually shut down before you get harmed what you can do to protect yourself when dealing with electricity use rcd protected circuits / sockets to plug your stuff into avoid path - if there is no exit for the current it'll not pass (exept for small capcitive leaks). wear shoes with isolating bottom (like skateboarder shoes) and dont touch anything with 2 hands avoid touching something with voltage. i learned the hard way to test old appliances with the back of my hand before touching them the normal way the guy with the multimeter - it might be a MOhm meter. its a multimeter that outputs few KV to test unstable resisance like damaged isolation. it looks exactly like normal multimeter

are you sure the dc dc converter is any safer than ac mains ?

Not even a little, my wanting to build a DC/DC converter is based entirely on rwlsford07 saying that disposable camera circuits are very inefficient for charging capacitors and if you want a faster charge to check out his DC/DC converter instructable. All I know is that it should be able to draw more power from the mains, more power = faster charge, rght?

hmmm.. car batteries.. use an inverter to get 12V into 120V ac, then put a 100ma fuse in the ac, after that, get a rectifier and turn the AC into DC, this will give you about 170V DC. charge the caps! but the only problem is that you can only charge your caps to 170V the 2100v AC capacitor you have, is out of a microwave, right? those capacitors have bleed resistors (it self-discharges)

... that was all in english right? XD I think the 2100v cap was from a microwave but it was a gift so I'm not sure.

You need to reply to his comment in using the button at the bottom right of comments or he won't know you did. You could potentially use a voltage multiplier that uses capacitors and diodes, it's not complex but still involves a connection to AC mains, if only uses capacitors and diodes, check out plasmana's 'ible on it, though it's not exactly a safer bet, however it's much easier to build.