I wish to control a transistor and relay by use of a light dependent resistor. *That is simple enough for a "nite light" application, by having the LDR as part of a voltage divider, but I would prefer if I could switch the transistor when the LDR shows a short-term change in resistance, such as when a person walks past in front of the ldr. *This could function as a crude motion detector. *Anyone have an idea of a circuit to do this? *The simpler the better. *THANKS.