Motion Detector Ultrasonic Movement Detector
The circuit uses a matched pair of 40 kHz transducer elements to detect movement up to 22 feet away. You may add a relay (not included) to switch higher voltage loads. The unit switches a LED for movement indication. Sensitivity is adjustable via control. Crystal locked circuit for maximum stability. A good circuit for detecting intruders, pets, etc., and then turning on a light, alarm bell, etc. 9 volt battery operation.
Motion Detector Ultrasonic Movement Detector Reviews: