My order from All Electronics arrived last weekend and I've been playing with things since. I figured this would be a quick and easy project, but for some reason that's not the case. I'm not sure what to do to get things up and running, so I figured I'd ask the users here to get some ideas.
The motion sensor works great when I have it hooked up to a light bulb. As it's designed, it will turn on the light when it's powered up for a few seconds and then kick it off until it sees motion. When I attach the relay to the output of the motion sensor (switched 120vac), the relay turns on but never turns off.
So, I tried one more config. I hooked the relay up in parallel with a light bulb. Lo and behold, it works! I figure this is because the relay is a coil (inductive load) and a light bulb is a resistive load. I suspect the motion sensor expects or perhaps even checks for a resistive load and when not seen, it doesn't send out any voltage. As a check, I hooked a DMM to the output and to the neutral and it only shows 1-2 volts when it sees motion.
I guess the easiest thing to do is to hook up a lightbulb in the garage as a motion indicator, but I'm really not interested in wasting a bunch of power. If I understand correctly, I could just use a resistor to simulate the light bulb. With the equation p=v^2/r, I could use a 240 ohm resistor to simulate a 60 watt bulb. If I want to use a smaller bulb, I could use a larger resistor (1440ohm for 10w). But, do I also need a diode and/or any other components to keep things working right?
I think for now I'll try finding the smallest wattage bulb I can and try that. Maybe I can use a CFL and get things down to 17 watt. Hmmm...