Hi I'm trying to build a 9v circuit that will operate a 8-12v latch at first light. The idea is to use a ldr to put power through to the latch, when the latch has opened a tilt switch then cuts the circuit until reset at night ready for the next morning. The only function of the ldr is to activate the latch in the morning, the trouble is I can't get it to work, I've wired the ldr in series with the latch and the latch will work if you short the ldr. Am I being too simplistic here? Can anyone help with a circuit diagram that would do the trick?