Theft Alarm Wireless Door Window Security Burglar Sensor Alarm circuit with Magnetic Anti Theft System for Home Office IC555 project. Fix the main circuit unit at the side of door or window.
Attach the bar magnet to door frame / window frame aligning with the reference line of the main unit.
Magnetic sensor switch detects entry protection your home or office whether you are in or out
As soon as doors or windows are opened, the magnetic sensor will trigger the alarm to go off at Beap Beap sound, which is normally hearable in home. Operated on 9 V DC (Battery Included)
The timer IC555 and Decade counter IC CD4027 are the main part of this circuit. The IR sensor used to receive IR rays from remote control, the relay act as a electro-mechanical switch to make close and open the load circuit with power supply.
This circuit operated by using 9V DC supply, this supply is directly given to the relay and in other way regulated as 5V by using positive regulator IC 7805. The regulated 5V supply given to the timer IC and counter IC, when the IR rays fall on the sensor it will produce spike signal at 36KHz, this signal act as a trigger signal for timer IC, by this trigger input timer IC will produce pulse output at the pin3.
This pulse duration and duty cycle can be varied by varying R5 and C4 components. The output pulse from timer IC should be least 1 second duration. This pulse output is given to the decade counter hence the counter IC produce set output at pin1 this will turn on the Q1 transistor hence relay connects load to power supply.
If the IR rays received by IR sensor during the counter output as Set condition the above all operation continues but the counter output turned to Reset hence the transistor Q1 turns off so the relay disconnects load from power supply.