03-01-2013, 03:30 PM
FIRE ALARM SYSTEM
ABSTRACT:
Should one can be cautious of various fire-prone zones such as Kitchens, Petrol bunks ,Industries ,especially ,Chemical industries , the fire at which may lead to several hazardous consequences ,calling for the installation of an equipment which can sense the possibility of fire hazards and accordingly can make alert the personnel working within the vicinity ,by proper alarming.
Based on the truth that fire always follows the smoke ,several fire detection circuits are made available in the markets .Our’s is such a mini circuit involving less cost.
The circuit mainly comprises of a Diode DR 25 as a sensor and NE 555 Timer. At room temperature the reverse resistance of the diode being very high, keeps the reset pin of IC at “ground potential”, thereby making the circuit unsound. In case of fire as the temperature in the vicinity of diode increases, the reverse resistance of diode drops, there by changing the biasing conditions of the circuit and ultimately leading to the warning alarm.
ABSTRACT:
Should one can be cautious of various fire-prone zones such as Kitchens, Petrol bunks ,Industries ,especially ,Chemical industries , the fire at which may lead to several hazardous consequences ,calling for the installation of an equipment which can sense the possibility of fire hazards and accordingly can make alert the personnel working within the vicinity ,by proper alarming.
Based on the truth that fire always follows the smoke ,several fire detection circuits are made available in the markets .Our’s is such a mini circuit involving less cost.
The circuit mainly comprises of a Diode DR 25 as a sensor and NE 555 Timer. At room temperature the reverse resistance of the diode being very high, keeps the reset pin of IC at “ground potential”, thereby making the circuit unsound. In case of fire as the temperature in the vicinity of diode increases, the reverse resistance of diode drops, there by changing the biasing conditions of the circuit and ultimately leading to the warning alarm.