Video Camera Intruder Detector
This circuit detects movement from a video camera. If you place your video camera in an area which has no movement and after a while someone steps into the viewing screen, this circuit will detect it. The sensitivity is controlled by R23 and can be adjusted to any movement. R3 adjusts the delay output time, it will go high for the set time. You can control any device with the digital output pulse. The heart of this circuit is the LM1881 which removes the Horizontal sync, vertical sync and for our purposes the odd and even fields from your composite video signal.