Throughout 2019 I started frequently dumpster diving for electronics to salvage components and see how anything that used electricity worked. Thrifting old disposable cameras for their flash capacitors and electric fly swatters for their HV supplies cost me about $10.
Eventually, I had acquired the following parts to build the coil gun.
- 2 photoflash capacitors (800uF 330V)
- HV supply from electric fly swatter
- Microwave oven door interlock switch
- piece of wood (to mount everything)
- Battery case made from
- paper jewelry box lid,
- hot glue,
- cardboard from disposable camera coupon,
- metal plates salvaged from electronic trash
- rocker switch (also from trash).
My beautiful trash circuit
My beautiful trash circuit hot glued to a plank of wood (with a wonderfully exposed HV capacitor bank)
Charged the capacitor bank to 350V (which they were not designed to handle).
Watch the video below to see the results.
After getting ahold of a 3D printer (a pandemic purchase) I was able to add some insulation between the user and the HV circuitry. Also replace the battery holder with a more robust plastic one. Also it was mounted to a nicer piece of wood.
Eventually the capacitor bank exploded while the circuit was charging. Luckily the 3D printed case contained it well enough that my ears were spared. I just threw the whole gun into the trash from which it came. I would like to make a solid state version in the future (or at least a version where I’m physically interfacing with a low voltage controller).
Eli Bartlit 
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