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digital timer with output

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skad33

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I am looking for an inexpensive timer with an output pulse. I would like it 12 volt. A digital clock style would be best that I could set to trigger a GM wiper motor to pulse one time twice a day. Any suggestions on where to find one would be appreciated. I am not sure on the amperage of the motor but most are fused at 20 amps.
Thanks
 
So you want a pulse lasting about 5sec every 12 hours?
How accurate does the 12 hour period have to be?
 
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It doesnt have to be that accurate. Even within an hour would be OK. Also the amperage of the output wouldnt have to be as high as 20 amps as I stated. The 20 amps is to run the motor not just to trigger the module, so lower amperage would be fine.
 
Use one of these.

12h=60000s. If you use all 16 bits, you would need an input clock running at a period of 60000/(2^16)=60000/65536=0.9155 sec. You can use the built-in RC oscillator to produce the clock.

You will get a CMOS output which is high for 6 hours; and then low for 6 more hours. Capacatively couple that to the gate of NFET switch. Use an RC time-constant of about 5s between the square wave and the gate so that the Fet is turned on for only ~ 5sec.
 
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