"animal feeder"

Hi

I am looking for a schematic for a timer that can start twice a day (every 12 hrs) and be on for 10 seconds. It will work like a animal feeder so it does not need to be that exact. I guess I can use two timers built around a 555 one sets on every 12 hours and starts the other one. But perhaps some know of any design either using PIC or anything more advanced than 555.

Any help is appreciated.
Here is what I mean: www.ghg.net/dharrison/ (microtimer2000)

Thanks in advance

simpler

Getting a 555 to have a 12 hour period will not work. You will be better off using the 555 to clock a counter. decode two states for the start and stop pulses on a RS flip flop to produce the 10 second output pulse.

If you are into programming you could also use a small PIC or AVR or whatever which has an internal oscillator, this would lead to a solution without any external components

u can use atmel 8951 and program it with digital clock that the clock will give pulse to 8951 to do the thing u want

For $5 you can buy a programmable AC timer from the hardware store. These are usually used for lights, etc., but you can plug in any ac device you want. You can also set multiple times per day.

Personally I would prefer a small PIC, using its internal RC oscillator.
If that is not an option, then you can consider an RC oscillator, such as 555, followed by a divider.
Or you can use the good old 4060 (CMOS 4000 series) that has an oscillator and a divider. Followed by a 4040, should allow you to get the timing you want.

You can buy 24 hour timers from any electrical store.
AB makes them. Build a voltage doubler to go from 12 to 24 VDC


Easy as pie