Explosion! Updated

A project log for Coil Gun/Gaus Cannon

A device that uses electricity to propel a projectile at a significant speed.

jeff.ballard.86jeff.ballard.86 04/30/2014 at 19:101 Comment

Today I switched out the photo transistors with photo diodes.

I then started testing.  started at 100v, 150v, on until i was up to 445v.  On this test, I had a protection diode explode! My coil protection consists of 5 6A diodes with a 300A peak wired in parallel with the coil.  

Sadly along with the loss of a single diode, I also must have blown some pins on my arduino,  and/or the LCD.  The arduino still seams to respond to some of my inputs.

an hour later and my ears are still ringing, and im still expecting the police to show up asking about the noise...


I went out to my garage to play with it a little, and what has happened is my second SCR has failed.  I was aware that this SCR wasnt completely right because it took an extraordinary amount of current to make it conduct, compaired to the other SCR.

Also the Arduino and LCD screen are fine, after the min explosion, it didnt seam to be working correctly, so I just powered everything down, a power reset was all that was needed it would seem. 

So I am now working with a single coil again, I will start to look for another SCR, and continue testing with the electronics.


I ordered 2 power diode modules, PN LS412460 they have a 20kA+ surge capability, I will use these as my new SCR protection devices.

I also ordered 5 SCR modules, each SCR module has tow SCRs wired in series, I'll wire all three terminals in parallel and use one of each banks for each coil.


dave.m.mcdonough wrote 05/01/2014 at 02:29 point
Well that stinks.
Post schematic? Maybe I will have some ideas to help.

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