Anna University Regional Campus Coimbatore
SUBMITTED BY-
SOUNDARYA.S
GRIJA.G
KAMALISUBASRI.R
FIRE ALARM DETECTOR WITH BC547 NPN
TRANSISTOR
ABSTRACT:
IN THIS PROJECT OUR OBJECTIVE IS TO DESIGN A
SIMPLE AND INEXPENSIVE FIRE ALARM CIRCUIT BY
USING A TRANSISTOR BC547 AND AN IR RECEIVER
SENSOR. THE FIRE CIRCUIT ALERT THROUGH
BUZZER SOUND WHENEVER ANY KIND OF FIRE
DETECTED IN THE AIR OR AN ENVIRONMENT.
INTRODUCTION
IN THIS PROJECT WE HAVE DESIGNES A SIMPLE AND INEXPENSIVE FIRE ALARM
CIRCUIT BY USING A TRANSISTOR BC547 AND AN IR RECEIVER SENSOR. THIS FIRE
CIRCUIT ALERT THROUGH BUZZER SOUND WHENEVER ANY KIND OF FIRE
DETECTED IN THE AIR OR ENVIRONMENT. IT CAN DETECT ANY KIND OF FIRE SUCH
AS RADIATION, HEAT, ETC. DEPENDING ON THE TYPES OF SENSOR THAT MATCHES
AN APPLICATION IS SELECTED. AN INFRARED LIGHT SENSOR, ON THE CONTRARY,
IS SENSITIVE AND VERY EASY TO USE.
COMPONENTS REQUIRED
BC547 TRANSISTOR(NPN)
INFRARED RECEIVER LED 220-OHM
LED
DC BUZZER
9 VOLT SUPPLY
BREADBOARD
CIRCUIT DIAGRAM:
DESIGN APPROACH
1. CONNECT THE IR LED WITH A CURRENT-LIMITING RESISTOR (E.G., 220-OHM RESISTOR) TO THE BC547
TRANSISTOR'S BASE.
2. CONNECT THE COLLECTOR OF THE BC547 TO THE POSITIVE TERMINAL OF THE 5V DC SUPPLY.
3. CONNECT THE EMITTER OF THE BC547 TO THE GROUND (0V) OF THE 5V DC SUPPLY.
4. CONNECT THE COLLECTOR OF THE BC547 TO THE ANODE OF THE IR LED.
5. CONNECT THE CATHODE OF THE IR LED TO THE GROUND.
6. CONNECT THE POSITIVE TERMINAL OF THE BUZZER TO THE COLLECTOR OF THE BC547.
7. CONNECT THE NEGATIVE TERMINAL OF THE BUZZER TO THE GROUND.
8. CONNECT AN LED IN SERIES WITH A CURRENT-LIMITING RESISTOR (E.G., 220-OHM RESISTOR).
9. CONNECT THE POSITIVE TERMINAL OF THE LED TO THE COLLECTOR OF THE BC547.
10. CONNECT THE NEGATIVE TERMINAL OF THE LED TO THE GROUND.
NOW, POSITION THE IR LED AND A PHOTODIODE (NOT EXPLICITLY MENTIONED IN YOUR COMPONENTS BUT
NEEDED FOR FIRE DETECTION) IN SUCH A WAY THAT THE IR LIGHT EMITTED BY THE LED IS REFLECTED ONTO
THE PHOTODIODE. WHEN THERE'S A FIRE, THE INFRARED LIGHT PATH MIGHT BE DISRUPTED.
WORKING
* IN THIS ALARM CIRCUIT, WE HAVE USED AN INFRARED DETECTOR LED. THE
INFRARED EMITTED FROM THE FIRE IS DETECTED BY THE INFRARED LED AND
VOLTAGE ACROSS THE INFRARED LED CHANGED.
* THE ANODE OF THE INFRARED LED IS CONNECTED WITH THE BASE OF THE BC547
NPN TRANSISTOR.
* DUE TO THE POSITIVE PULSE IN THE BASE, THE TRANSISTOR TURNS ON AND
CURRENT CAN FLOW IN THROUGH BUZZER-COLLECTOR-EMITTER.
* IF THERE IS NO FIRE THE NO POSITIVE PULSE FED TO THE TRANSISTOR REMAINS
IN OFF MODE. SO THAT TIME CURRENT CANNOT FLOW THROUGH THE BUZZER.
ADDITION OF AUTOMATIC EXHAUST SYSTEM
* THE EXHAUST SYSTEM SHOULD BE TAKEN INTO CONSIDERATION WITH THE FIRE ALARM
SYSTEM.
* WHEN THE SYSTEM DETECTS FIRE, THE MOTOR WILL ROTATE THE BLADES OF THE
EXHAUST FAN. SINCE, IT IS CONNECTED PARALLEL TO THE BUZZER.
* THIS IS NECESSARY AS THIS WOULD ALLOW THE SYSTEM TO EVACUATE THE HEAT AND
SMOKE FROM THE FIRE.
* THE EXHAUST SYSTEM WILL SIGNIFICANTLY REDUCE THE NUMBER OF CASUALTIES
FROM SUFFOCATION
* HENCE, IT CAN ACT AS A LIFE SAVER.
APPLICATIONS
• A FIRE ALARM DETECTOR SYSTEM IS CRUCIAL FOR VARIOUS SETTINGS TO ENSURE EARLY DETECTION AND RESPONSE
TO POTENTIAL FIRES. COMMON APPLICATIONS INCLUDE:
1. RESIDENTIAL BUILDINGS: PROTECTING HOMES BY DETECTING SMOKE OR HEAT, PROVIDING EARLY WARNINGS TO
RESIDENTS.
2. COMMERCIAL ESTABLISHMENTS: SAFEGUARDING OFFICES, RETAIL SPACES, AND WAREHOUSES AGAINST FIRE
HAZARDS TO PROTECT PEOPLE AND ASSETS.
3. INDUSTRIAL FACILITIES: MONITORING MANUFACTURING PLANTS AND WAREHOUSES WHERE FIRE RISKS MAY BE
HIGHER DUE TO MACHINERY OR STORED MATERIALS.
4. EDUCATIONAL INSTITUTIONS: ENHANCING SAFETY IN SCHOOLS AND UNIVERSITIES TO PROTECT STUDENTS, FACULTY,
AND FACILITIES.
5. HEALTHCARE FACILITIES: ENSURING PATIENT SAFETY IN HOSPITALS AND CLINICS BY QUICKLY DETECTING AND
ALERTING STAFF TO POTENTIAL FIRE THREATS
CONCLUSION
IN CONCLUSION, FIRE ALARM DETECTOR SYSTEMS PLAY A CRUCIAL ROLE IN
SAFEGUARDING VARIOUS ENVIRONMENTS, INCLUDING RESIDENTIAL,
COMMERCIAL, INDUSTRIAL, EDUCATIONAL, HEALTHCARE, HOSPITALITY, PUBLIC
SPACES, TRANSPORTATION HUBS, DATA CENTERS, AND WAREHOUSES. THESE
SYSTEMS PROVIDE EARLY DETECTION OF POTENTIAL FIRE HAZARDS, ALLOWING
FOR SWIFT RESPONSE MEASURES TO PROTECT LIVES, PROPERTY, AND CRITICAL
ASSETS. THE DIVERSE APPLICATIONS HIGHLIGHT THE IMPORTANCE OF
IMPLEMENTING RELIABLE AND EFFICIENT FIRE ALARM SOLUTIONS TAILORED TO
SPECIFIC SETTINGS AND SAFETY REQUIREMENTS.
THANK YOU
