Ir Security Alarm Circuit Diagram. Alarm turns off after about 5 10 seconds of getting the contact with ir again. Ir based automatic door security alarm circuit diagram.
Ir based automatic door security alarm circuit diagram. The infrared radiations are continuously falling on a photodiode. The circuit diagram of the ir sensor using transistors namely obstacle detection using two transistors is shown below.
When the system is powered on the ir transmitter or ir led emits infrared light.
So this circuit can be built with two transistors like npn and pnp. The working of the circuit is as follows. This burglar alarm system circuit is using a infrared proximity detector that triggers an alarm when the rays. In the circuit the reed switch is connected across the reset pin 4 of the 555 and the ground.
