Gel Box

This is a simple DIY gel box. It does not require any sensors or control electronics.


  • Power supply (we use a 0-120V DC regulated power supply)
  • Small plastic container
  • Larger plastic container (the smaller food container should be able to sit inside)
  • 2-4 plastic spacers at least 1/2" tall
  • 2 banana jacks and wires
  • Platinum wire for positive side (we use 6" of 0.005" diameter wire from eBay)
  • Other wire for negative side (we use 6" of 0.013" nickel chromium wire from McMaster)
  • Electrical tape
  • Waterproof glue
  • Gel comb (we used cardboard, tape, and LEGO blocks)

Assembling the Gel Box

  1. Cut off two opposite ends of the small plastic container. Ideally, you want the final size to be at least 2.5 inches from end to end.
  2. Use the waterproof glue to mount the plastic spacers to the inside of the larger container, close enough together that the small container can rest on top of them.
  3. Cut two holes in the top edge of the large container, along one of the longer sides of the container. Mount the banana jacks through these holes.
  4. Attach the platinum wire to one of the banana jacks and run it along the bottom of the large container.
  5. Attach the other wire to the other banana jack and run it along the bottom of the large container on the opposite end.
  6. Use a couple small squares of electrical tape to hold the wires in place. Do not cover the wires in tape; the wires needd to be exposed for the gel box to run properly.