Depends on the ldr ... send light versus dark resistance range .
u may be able to drive a high resistance relay in series to the relay or use opto.
Or you could use a switch and put it on/off at a speed of 50 times a second with your fingers , or 25 times a second or 15 times... thus getting control
sorry couldn't help it just joking ....ha...ha...ha...:-D:-D:-D
more if its a micro motor taking very little current it will work ldr in series to motor.
just thought about it now sure if one ldr can take say max 1 ma and u need 100ma u will need 100 ldr and now i am not joking i saw on ebay sales of 200 ldr for 10$ only last year
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