Magnetic Door Alarm Working Model

Description

Vigyanics Magnetic Door Alarm kit is a working model that can be attached to any door. It activates an alarm whenever the the door opens. The main component is Reed switch or magnetic switch. If any magnet comes near the Reed switch, it becomes closed otherwise it remains opened. Hence a magnet can be attached with the door. If door opens, the magnet being away from the sensor will be activated. The switching of buzzer and LED is done through a transistor. As long as the magnet is near the Reed switch, the base of transistor remains connected with ground and hence transistor remains off. If the Reed switch becomes open, the base of the transistor goes at high voltage and transistor allows the flow of current and buzzer & LED are switched ON.