Instructables
I have recently found out how much fun it can be to short circuit the leads of a charged capacitor after zapping myself while opening a disposable camera.

It wasn't long before I decided to start messing around with capacitors and creating some sparks. Soon I noticed how time spending it was to connect the capacitor to the power supply, charge it, disconnect it and just then, short the leads.

So this came to me, a little device that will charge the capacitors and disconnect them for you. The best part is that the speed at which they are connected and disconnected from the power supply can be regulated.

Even though in this Instructable I will be using low voltages such as 20v, I believe you can, by using higher voltage capacitors do the same with much bigger sparks and fun.

So let's get started!


NOTE:

I am NOT responsible for any Zapping caused to you by this project. If you choose to add higher value capacitors and use a higher voltage I am not responsible for whatever the outcome of such ideas is. It might end up being fun or it might end with some nasty burns.

The Schematic is to be opened using Eagle Cad.




 
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Himers13 days ago

This is great!!! I might use this to make an automatic coil gun.

dean141112 years ago
you know what. i found out about caps the exact same way you did, and man does it hurt!!! im going to post an instructable about how to build somthing sourt of like yours, but i dont have all the parts yet, so check up on me because ill be doing that instructable soon!!
GranTotem (author)  dean141112 years ago
Well I am Happy to learn that you want to make one like mine.

Since you are going to do so, you might want to try using a disposable camera to charge the capacitors. That means that they will have a charge of about 400v if im not wrong.

That is some pretty nice sparks I bet. Just take into account that it might not work like mine, you might not be able to make it spark like crazy. Already at 20v the metals, when they touch each otherm they stick together. They melt. So at 400v you might end up with a soldering iron.

If not you might want to use capacitors with a larger capacitance, say 1 Farad.

Happy Building!
I have a bank of 100 330v 180uf caps they can put a quarter size hole in a coke can the dont stick very much (some times) but because it just vaporizes the wire
Dam bro thts nearly a kj so ...... Did u collect those or did u just buy em
Collected them but had the hole thing including the charger done in a week
Nice it cool hearing from Peru.... My mom grew up there
What i live in the U.S in montana?
I have a capacitor bank that is 5200 farad at 2.5v and it will make some nice sparks and even melt 14awg solid copper wire. It takes a long time to charge up though.
see mune charges in 30 seconds
GranTotem (author)  rocketman2212 years ago
Ohhh, So what changes the "melting" capacity of the bank as you call it is the capacitance and not the voltage?

Because when I was designing it, I played around with values and voltages, and it seemed like they both affect. The higher the voltage and the higher the capacitance the bigger the sparks. When I lowered voltage the sparks decreased in size.

Thanks
The stored energy measured in joules changes the "melting" capacity.
When you double the voltage the stored energy quadruples.
Here is a calculator that shows the stored energy in a capacitor.

Your bank charged to 25v has just under 1 joule. Mine charged to 2.5v has 16,250 joules. A common disposable camera capacitor 120uF at 330v has 6.5 joules.

My bank is made with boost caps which won't discharge quickly. They will discharge in about 5 seconds at the fastest.
GranTotem (author)  rocketman2212 years ago
Sir, You have just boosted my mad scientis level.

Please tell me more on how you made this capacitor bank.
Also, what is the main use of a capacitor bank, I've heard about them but I can't see the use except for doing what my proyect does and maybe melting metals together.

Where on earth did you get a 5200 Farad capacitor?

On the shop I go to, they barely have capacitors up to 100F and they are huge.
It's actually 2 2600F caps in parallel (Maxwell BCAP0010). They are normally used to supply or store large bursts of power. I bought them to make a led lantern flash light that will run for an hour and charge in 30 seconds, but I haven't got around to building it yet.
I got them as surplus quite cheaply. They are very expensive new. I got mine from electronic goldmine a while back. Sometimes they get more in but they sell out very quickly. An ebay search for "maxwell ultracapacitor" turns up a few of them.
actually ive already made one and the charger to go along with it, so even before i saw your instructable i was planing on making one that was more powerful and had a charger built-in. i just need more caps and yes i do get them from old disposable cameras from cvs or walgreens (you can get them for free if you ask right) so anyway keep a look out for that instructable. :)
09khanyu2 years ago
I have got an idea for you. Could you consider making the power supply small and portable(will not last long,) and then make a pocket arc welder.
GranTotem (author)  09khanyu2 years ago
I tried soldering to pieces of metal together but the charge that this generates isn't enough to melt the metals.

It will although make the two pens stick together a bit but they easily come apart.
I would have to use a higher voltage and probably, as some people have told me that would kill the relays due to arcing unless I used a snubber or something like that. I still have to go over this circuit again to make it more efficient in terms of the relays and the supposed arcs that are created between contacts.

So if you can tell me how to get AC from a 9v battery I would be happy to try this out.
That is all way beyond me. The most advanced thing I have done is turn off my TV with my Arduino but maybe one day when I go to university I will return to this.
jimvandamme2 years ago
You can calculate the energy stored in each capacitor using the formula 1/2 C (V squared), where C is the capacitance and V is the voltage. Usually C is in the microfarad regoin, so pretty small, but when you increase the voltage the energy goes up by the square. 10 times the voltage, 100 times the energy! (The result is in Joules.)

I design, build and run big radar transmitters, and some use capacitors of around a microfarad. Not much, but they charge up to 40, 000 volts. When you short across THAT, you'd better have ear protection on, and stand behind something solid, and don't look at the arc.
GranTotem (author)  jimvandamme2 years ago
That sounds awesome.
Purely Awesome.
This brings back old (old) memories. Back in the 60's while stationed in Fort Sill, OK and living in a barracks with 20 to 30 other electronic nerds we played with Capactors as well. We were using 120v Caps and larger, charge them up and after lights were out, would launch them into the air. When they came down the leads would migrate closer together and the blue arcs that came out were brilliant. Of course some of us were not that brilliant and some of US tried to catch them in flight. Not recommended for the sane.

Thanks for the memories.
Ah, yes. The days of the Capacitor-Box all charged up with a sign saying "Do Not Touch This Box" and waiting for some fool to pick it up. It taught people to regard safety signs.
milnuete2 years ago
Very fun instructable, some people use capacitor banks to feed high energy pulsating lasers. Regarding your 16 ohms equivalent age I just want to tell you that:
1 ohm = 1.139 x 10^(-12) sec/cm

so you would need to multiply 16 ohms by some particular constant distance (in cm) in order to get your right age, which is that? or is it a secret?

Best Regards
Jorge
GranTotem (author)  milnuete2 years ago
Ahh My dear Friend,

I recommend you to read again carefully.

;)


gardenville2 years ago
Hi,

Interesting project. Could you minaturize this small enough to go into a model trolley car. The point of the spark would be where the trolley pole touches the overhead wire.

I want to control the trolley with Radio Control and use a Battery for power. This way I don't have to have the overhead wire "HOT". The "Cap's N Sparks" device could create the spark at the where the trolley pole touches the overhead wire. The spark would make it look very real.

This youtube video shows the kind of spark I am looking for:

http://www.youtube.com/watch?v=unhXEQQk8G8

Thanks,

Bill
GranTotem (author)  gardenville2 years ago
Yes I believe you can, You would have to replace those 2 relays for 1 DPDT, something I forgot to explain how to do.

Remove the extra relay for the LED's. Now instead of 3 1000 uF caps just buy one of a higher capacitance say 5k uF.

You might have some problems with the relay. I have received some commentaries at HackADay saying something I didn't know about, called arcing.
So you might want to wait a little bit while I try to figure out how to "protect" the relays from these arcs. Also you might have to use a 9v battery to power the relays unless you can find a 3v relay.

Regarding the charging of the capacitors, well, you might have some problems here as well. How will you charge them, I was recommended to use only 1 power supply, but in this case, if you have your trolly on a rail you could have the 20v running through the rails onto the capacitors and have the overhead wire be connected to the 20v ground to do the short circuit.

If you could send me a picture of what the trolley looks like I would be happy to help you.

Sincerely GranTotem
Iridium72 years ago
You should also put a warning saying that you should never place either lead going to your heart, face, or spine. That will also help. Good 'ible though. I'll be sure to make one sometime.
Hahaha - that's a good one. Surely, you are being sarcastic, right?

I look at it this way, if someone needs warnings so basic, or even about the incredibly obvious possibility of electric shock - they should NOT be playing around with electricity/electronics in the first place.

Maybe gardening would be safer - hmm, but then you'd have to warn about potentially sharp trowels, not to eat fertilizer, possible drowning from the water hose, sunstroke, insect bites etc. etc. People need to take some responsibility for their own actions, instead of making it everyone else's to keep them safe. Just a thought. (Or does this have to do with rampant sue-happy people in the US who will blame the author if they get hurt?)

Great comment though!!
GranTotem (author)  Iridium72 years ago
Yeah... I once read about a guy who took a charged car audio capacitor, one of those big ones, and touched both leads with his tongue... He thought it was discharged.
static2 years ago
Folks this is great nice build for the living room, unless someone near is listening to AM radio. To see the ultimate capacitor discharge machine see the geek group's thumper.
http://www.youtube.com/watch?v=M-P9BV0r6QM
DrSimons2 years ago
Nice project. I agree, this is a great thing to do and there should definitely be some videos up in here. For anyone new to playing with capacitors, it's probably wise to point out a few things (sorry if you already mentioned any).

1, never use a voltage higher than the capacitor's rating. At very least it will leak, and worst it might damage the cap and/or explode.

2, when using electrolytic caps (the big black ones) NEVER wire it backwards. If the polarity is wrong it WILL explode. So pay attention to the lead that has a bunch of minus signs (-) going up the side.

3. Be wary of thin wires vaporizing or the contacts welding together. When I first did this using a disposable camera (which comes with a built-in charging system, by the way!) I actually welded a screwdriver to the capacitor terminals.
GranTotem (author)  DrSimons2 years ago
Thanks, Do you think I should add a precaution slide to the instructable?

4. Never Ever touch both leads of the capacitors with any part of your body when charged.

Couldn't hurt. Might consider mentioning safety goggles too, a sufficiently powerful discharge could send sparks into your eyes.
Congrats! You have made a 555 Flyback transformer Driver!
You might want to also check out ZVS Flyback drivers...
You might also be interested in (Youtube user) Telsabang's HV Power supply:
http://www.youtube.com/watch?v=ypNy3g_1t2I&feature=plcp
biolethal2 years ago
Cool, i like the finished look of this bank. I'm working on programming a 2.6Kj 400v capacitor bank right now. The capacitor bank you built may benefit from a bypassable SCR to switch the capacitors through things, so you get more efficiency and less switching losses.
GranTotem (author)  biolethal2 years ago
Thanks, Ill take that into account. By the way your project not only sounds fascinating but worthy of a video! I would love to see the sparks that 400v would create.
Kiteman2 years ago
Video! Give us video!
GranTotem (author)  Kiteman2 years ago
Video it Shall be! I'll make one as soon as possible.