3 Review(s)

This kit can be attached to any door. If the door opens, it will generate an alarm. The main component used here 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 openes , the maganet will go away from the sensor and it will be activated. The swtiching of buzzer and led is done here through a transistor. As long as the magnet is there near to the reed switch, the base of thr transistor Q1 remain connected with ground and hence transistor Q1 remains off. If the reed switch becomes open, the base of the transistor (V3) goes at high voltage and hence transistor gets turned hence buzzer and led become on.