DIY Based Fire Alarm

This fire alarm is very simple and is based on a transistor, buzzer and tube light starter.

1. Tube light starter

2. Solder iron and solder wire

3. bc547

4. buzzer

5. perfboard

6. 10k resistor (brown, black, orange, gold)

7. snip connector

8. 9-volt battery

Disassemble the tube light starter carefully to retrieve the bimetallic strip.

First of all, break the plastic case and then carefully retrieve the bimetallic conatct after breaking the glass.

Assemble the circuit as given in the diagram. I had mentioned the emitter, base and collector of transistor bc547.

How it works?

When matchstick is lit near the bimetallic contacts it connects with each other since they both have different heat of expansion. As we know metal expands on heating.

Here is the picture of fully assembled circuit.

Watch out the video: