PIR. motion sensor alarm circuit
A motion detection alarm circuit using a PIR.SENSOR motion detection, if the move is a positive light from the PIR sensor, triggered by a delay circuit, Q1 and relay it to work and hold for about 20 seconds. to apply to the siren to signal a warning to stop, or discarded by the switch S1 is a switch that controls it. Or a remote control.
Most Wanted Diagrams: