Sean:

I am sure John will come up with a great circuit to do this. I might take the cheap way out and get an inexpensive digital alarm clock. disconnect the leads that go to the clock's noise maker. Use those leads to fire a latching relay. The output voltage from the clock would have to be known before choosing a relay.

Assuming 12volts you could use an NTE RLYF1A012 this relay will only draw 12mA so should not overload the clock's output circuitry. You will want to add a resistor and capacitor across the relay's coil to keep it from cycling on and off as the clock pulses. 5,000 Ohms and 100mf in series across the relay coil will hold it closed ( assuming the clock pulses once per second). Once you turn of the alarm the relay will open in roughly 1/2 second.

the relays switch contacts will supply the 9 volts from your battery to the camera.


Pat Ziegler
Wholesale Electronics Inc.

www.weisd.com














wrote in message ...
Sean:

A couple of questions,

Does this have to happen at a particular time of day? Or, four hours
after you start the count down? And, Do you need an off time?



Pat Ziegler
Wholesale Electronics Inc.
www.weisd.com




Hi Pat,

I would like it at a set time during the day but I'm not bothered
about an off time.

Cheers,
Sean