rrlsmontana said:
Thanks for your info. Yes, I guess I need a schematic. I haven't been able to find anything simple enough for my mechanical brain on the web.
Thanks!
Paul
I've made some assumptions like your motor is a small DC (< couple 100 mA's) and that the CDS cells you'll get from radio shack have something like Megohm resistance in full darkness and couple of 100 ohms with alot of ambient light shining on them.
You'll likely have to tweak the resistor divider to find just the right amount of light you want to switch your motor on.
I'm also assuming that the 5V relay won't have a problem running with almost 6V across the coil. A darlington switch transistor would have been better here dropping that extra volt for you but I couldnt find radio shack offering a darlington.
If you have trouble actually getting these components, get something as close as you can, there will likely be an easy way to make it work.
Radio shack numbers:
#271-1335 10K 1/4W 5% resistor
#271-1321 1K 1/4W 5% resistor
#276-1657 CDS cells
#276-2058 2N4401 NPN transistor
#276-1102 1N4001 rectifier diode
#275-240 5V, SPDT relay, 1A contacts