I needed a reliable fish feeder for my pond for when I'm away. This instructable gives details on the feeder that I just finished building and testing. The same idea could be used for feeding other pets or for an indoor aquarium. I made a number of internet inquiries to find out details on the microwave carousel motor that I planned on using to drive the auger. The problem with the motor is that it will often reverse rotational direction when it is turned ON and OFF and ON again. I learned from internet contacts that a ratchet would solve the reversing problem so that is what I ended up using here. A short demo near the end of the video (below) shows me stalling the motor to reverse direction. Some microwave carousel motors work directly from the line voltage in which case you wouldn't need a transformer. However I feel comfortable with the lower voltage setup for this application as it gives an extra level of safety when the feeder is operated outdoors. The electronic timer allows programmable ON and OFF times for the motor. (Better still if you have or can find a gear head dc motor the rotation direction is controlled just by reversing the polarity of the connections.)
I decided to change the name of this instructable to Automatic Pet Feeder from Automatic fish feeder as viewers are using the idea to feed other things...
In any application like this it is important to plug the timer into a ground fault circuit interrupter (GFCI) electrical outlet.
will give u a look when i make mine...