fish feeder

[mklotz]

Frank, you must be reading my mind.

I had similar thoughts with my abortive feeder. I'll forget to reload it so it needs to have a large capacity hopper. I ended up building a cardboard bin with an angled bottom so feed would be forced by gravity to the bottom center. At this center I mounted an auger I had hand-carved from a wooden dowel. As the auger turned, food would be carried along outside the hopper where it would drop into the tank.

The auger was connected to a small, geared-down DC motor. Using a 555, I constructed a circuit that, when triggered, would pulse the motor long enough to turn the auger through three revolutions.

Now came the problem of how to trigger the circuit. Using something simple like a clock was too easy for this idiot. I had to do something really technical. I had a photoelectric switch I had recently built so I decided to set it up outside the fish tank. If a fish swam in front of it, the motor would be triggered and the auger would dump a little reward into the tank. You can't imagine how clever I thought I was.

I filled the hopper and we went away for a long weekend. I either underestimated the activity level of fish or overestimated the amount of food to deliver with each turn of the auger; when we returned the hopper was empty, the tank was cloudy as hell, and half the fish were dead.

Since then it's become a family joke. Don't let Dad feed the dog; he'll build some contraption that'll kill the dog.