ABSTRACT :
The circuit of Pyroelectric Fire Alarm is an Ultra sensitive fire sensor that exploits the direct Piezo electric property of the Piezo element to detect fire. An ordinary Piezo element of Buzzer is used as the Fire sensor. The Lead TitanateZirconate crystals in the Piezo element have the property to deform and generate an electric potential when heated. This property is exploited in the circuit to make an ultra sensitive Fire Alarm. Unlike Thermistor based Fire sensors, this circuit can detect a 10 degree rise in temperature and gives a warning alarm even before the fire breaks. If the temperature continues due to fire, it automatically operates a relay which can be used to switch on a Water sprayer or Solenoid pump to spray water or fire ceasing foam.