FIRE ALARM CIRCUIT
Abstract
This circuit may be used as an alarm that sounds anytime the temperature rises over a certain
threshold. The project employs a 5 volt power source and is based around an AT89S52 microprocessor.
When a fire is detected, it immediately turns on the buzzer and motor. Both fire detection and fire control are
possible with it. For this project, a controlled 500mA, 5V power source is used. Voltage control is
accomplished using the 7805 three terminal voltage regulator. The secondary output of the 230/12V step
down transformer's ac output is rectified using a bridge type full wave rectifier.