Very Sensitive Fire Alarm Circuit Using Relay

by Utsource123 in Circuits > Sensors

1829 Views, 3 Favorites, 0 Comments

Very Sensitive Fire Alarm Circuit Using Relay

20190926_204535.jpg

Hii friend,

Today I am going to make a circuit of Fire Alarm which is very sensitive.Today I will make this circuit using Relay and Transistor BC547.

Let's get started,

Components Required -

20190926_203957.jpg
20190926_203941.jpg
20190926_203744.jpg
20190926_203757.jpg
20190926_203728.jpg
20190926_203709.jpg

(1.) Photodiode x1

(2.) Buzzer x1

(3.) Relay - 6V x1

(4.) Transistor - BC547 x1

(5.) Battery clipper x2

(6.) Battery - 9V x2

Transistor - BC547

20190926_203913.jpg

This is the pins of this transistor.

C - Collector,

B - Base and

E - Emmiter.

Connect Transistor to Relay

20190926_204018.jpg

Firstly we have to connect transistor to the relay.

Solder Collector pin of transistor to coil-1 pin of the Relay as you can see in the picture.

Connect Photodiode

20190926_204029.jpg

Next we have to connect Photodiode to the relay.

Solder Cathode leg of Photodiode to Coil-2 pin of Relay and

Anode leg of Photodiode to Base pin of the Relay as solder in the picture.

Connect Battery Clipper Wire

20190926_204056.jpg

Next solder +ve wire of battery clipper to Coil-2 of Relay and

Solder -ve wire of battery clipper to emmiter pin of the transistor as you can see in the picture.

Next Connect Buzzer

20190926_204217.jpg

Solder -ve pin of buzzer to common pin of the Relay.

Connect Second Battery Clipper

20190926_204242.jpg

Now we have to connect second battery clipper wire to the circuit.

Solder +ve wire of battery clipper to +ve pin of buzzer and

solder -ve wire of battery clipper to NO (Normally Open) pin of the Relay as you can see in the picture.

Connect Batteries to Battery Clipper

20190926_204310.jpg

How It Works

20190926_204404.jpg
20190926_204339.jpg

When fire will burn around this circuit with distance approx 5Cm then Buzzer will give sound automatically.

NOTE : We can also connect 3V LED to this circuit.Connect 3V LED with 220 ohm resistor in the parallel of Buzzer.

Thank you