Problem

Racoons are a recurring theme now, on this blog. However, this time it’s more more sinister. They’re not knocking over garbage, they’re defecating in a pool. It was really gross.

The last time Racoons gave me trouble, my solution was to rig a sprinkler to a motion sensor. That wasn’t a safe setup, however.

Solution

This time, I thought I’d go with something smaller and safer but still cool! I went with this water gun. and this PIR motion sensor and then just a low volt. relay and an NPN transistor.

And just to make it seem a little more stock and easier to use. I built the motion sensor into a Nerf rail attachment so that it was easily removable as well.

I think this quick schematic is how I pulled it off (It was a year ago or so when I made it.)

The Motion sensative water gun schematic

And finally, here’s a build gallery with probably enough detail to recreate this, if you like! :)

Build Gallery

: This is the motion sensor, and it does all the work for me! It’s even got ‘Pots’ for changing sensitivity to motion and timing (how long the gun will fire when it senses motion)