tofarley

I'm looking for something similar as well. I have a circuit that uses a motion sensor. Typically, the output from the motion sensor powers the base of an NPN transistor. For my project, I would like to power the circuit when the motion sensor *stops* registering. Not to say the circuit should run continuously (in which case I would simply substitute a PNP) The circuit should activate once, to operate a solenoid, whenever the motion sensor stops sensing. I'm hoping for an analog solution to this problem. Any assistance would be greatly appreciated!