Pressure Plate Light Switch Made From Beer Cans

After a night out, it can be a real hassle trying to unlock your door in the dark. What you need is a sensor that turns on a light as soon as you’re standing at your front door. Here’s how to make a sensor that does exactly that—no more fumbling for your keys in the dark.

18 empty beer cans - soda cans will also work.

Sellotape

Foam

Light

Take a can and cut around the top using a snap-off knife. When you’re almost all the way around, switch to a pair of scissors to finish the cut. Trim around again to make the edge straight. Cut off the bottom in the same way. Do the same with 18 cans.

Flatten the cans by cutting them open and then sliding the cut pieces over an edge to smooth them out.

To improve electrical contact, sand the colored side of the can using 80-grit sandpaper. Sand lengthwise, then crosswise, and finally crisscross diagonally. Flip the aluminum sheet over and sand the edges as well.

Create two larger sheets by joining nine sheets together, overlapping the edges, and securing them with sellotape.

Cut some foam to create a gap between the two sheets. Use sellotape to attach the foam strips to one sheet, then place the second sheet on top.

Modify a battery-powered light so it turns on using the pressure plate. This is done by sanding both sides of a couple of small aluminum pieces, then separating them with a small piece of plastic. Slip this between one of the battery contacts. Attach a pair of wires, connecting the other ends to each side of the pressure plate. Use a couple of alligator leads to test that everything works. A mat was placed on top to ensure its weight alone wouldn’t trigger the light without someone stepping on it.

Place the completed pressure sensor light in front of the door. Now, when you step on the mat, the light will turn on, making it easier to open the door at night.