simple coilgun?

, Sat Apr 08 2006, 04:53AM

i have heard of camera flash caps being used for coilguns, is this efficient? can i use the original circuit and just discharge the cap across a spark switch into a coil?
Re: simple coilgun?
Psyko, Sat Apr 08 2006, 09:28AM

Camera flash caps can be used for low power coilguns. They store approx. 6 joules. Efficiency does not depend on wich cap you use, just to your coilgun design. Of course you can use the original circuit, a then discharge the cap into a small coil. This was my first approach into coilguns, and I havee used the flash tube soldered on the board as a triggered sparg gap. Perfect, if you don't have a switch, and the slug will be fired with a nice bright flash
Re: simple coilgun?
Desmogod, Sat Apr 08 2006, 02:42PM

Here's the info you are after.
Link2
Or here
Link2
Re: simple coilgun?
, Sat Apr 08 2006, 04:51PM

tahnk you for the help me and my friend made a small one on 85 volt with a lot of big capacitance, shot a nail 3 feet
Re: simple coilgun?
Sonny, Sun Apr 09 2006, 01:24AM

Buy some small capasictance 300-450V capacitors (~2000uF) quite cheap on ebay. If you want it easy go for SCRs and make a high current coil ( one stage). That should give you a quite nice coilgun. MOSFETs are better and more efficient but more expencive (i'm building a MOSFET driven one at the moment).

Sorry for my bad english the moment, have consume to much alcohole ;)
Re: simple coilgun?
, Sun Apr 09 2006, 06:10PM

lmao too much alcohol well what exactly is an SCR? is it like a transistor? and that is what switches the coil on or off? the one i made had a rewound MOT with an 85 volt ac secondary and i full wave rectified it to charge caps, and then i put the power to the coil through a circuit breaker, i did the ghetto coil gun
Re: simple coilgun?
Sonny, Sun Apr 09 2006, 07:42PM

streamers rule wrote ...

lmao too much alcohol well what exactly is an SCR? is it like a transistor? and that is what switches the coil on or off? the one i made had a rewound MOT with an 85 volt ac secondary and i full wave rectified it to charge caps, and then i put the power to the coil through a circuit breaker, i did the ghetto coil gun


An SCR is a thyristor Link2 . It's like a diod you can turn on and off. In other words a solid-state relay. And yes, that's what switches the coil on and off ALMOST. You can't really switch off an SCR based coilgun so you have to wind the coil equal to the capacistance of your capacitor.

My advice is to make a FET/IGBT based coilgun so you can turn OFF the coil when the timing is right. This way is a more efficient way too.
Re: simple coilgun?
, Sun Apr 09 2006, 08:16PM

is there a really a good way to use a fet/igbt, because i am pretty sure that the power from the caps is pretty high amperage, and a good fet to use?
Re: simple coilgun?
Self Defenestrate, Sun Apr 09 2006, 08:49PM

At this point I'd stick to SCR's, they're easy to trigger, and given the right ratings can be put through some brutal discharges. IGBT and FET based systems take alot of tweaking to perfect. Look up 'ohms law' to figure how much amperage will flow through your coil. On a more serious note, lay off the booze, nothing good ever happens when your drunk.
Re: simple coilgun?
rupidust, Sun Apr 09 2006, 08:52PM

It will be alot of effort to implement an IGBT controlled cg for beginners not knowing what SCRs are. IGBT control requires SCR control knowledge + more. Otherwise, the IGBT is unforgiving and has a stock count that leaks like a sieve and a mirroring cash deficit. Not a "Re: simple colgun".
Re: simple coilgun?
Wolfram, Sun Apr 09 2006, 08:53PM

Closed. A simple google search will give you enough information to make this coilgun. I entered "disposable camera coilgun" (without the quotes) into google and got several pages telling you how to make simple coilguns from disposable cameras.