Construction of Car Security Alarm Intruder

The main objective of this project was to ensure a proper security to car being parked in garage against theft or an intruder. The circuit uses two NE555 timers; one of the NE555 was wired as a monostable oscillator and remaining wired as tone generator and amplified to obtain a maximum audible sound. However, pin 2 of the first NE555 was used as sensor part. When pin 2 has contact with human body or hand it will activate the IC1 which will also bias transistor and this transistor was wired in a way that once it is powered it will close circuit thereby passing a negative supply voltage to Radio Frequency module which will send signal to the receiver, the receiver circuit will then trigger alarm circuit and outputted out through a loud speaker or buzzer. This device however, is a security device against car-theft as stated above. It is an electronic device that is connected to the battery of the car it is being installed in and gets activated when the car engine is switched off and the car stationed at a place. The device is not seen but, it has an indicator light which shows that the alarm has been activated. When the body of the car is touched by human hand, it sends a negative signal to the device which needs a negative pulse to get activated; it sends this negative from the human hand to the tone generator IC which triggers the alarm.