This is a fire alarm working model using a tubelight starter. The starter contains a bi-metallic strip that responds to heat. When a flame (from a matchstick) is brought near, the heat bends the strip inside the starter, completing the electric circuit.
This allows current to flow and activates the buzzer, simulating a fire alarm. No sensor is used — only the heat-sensitive property of the starter.
Materials Needed:
- 1 tubelight starter (FSU or similar, 4–22W type)
- 1 buzzer (6V–12V)
- 9V battery and battery clip
- Connecting wires
- Matchbox (to demonstrate flame)
- Cardboard (for base)
- Tape or glue
How to Make Fire Alarm Working Model
Step 1: Connect the Circuit
- Connect one terminal of the tubelight starter to the positive wire of the 9V battery.
- Connect the second terminal of the starter to one terminal of the buzzer.
- Connect the remaining buzzer terminal to the negative terminal of the battery.
So the full circuit path is:
Battery (+) → Starter → Buzzer → Battery (–)
Step 2: Fix the Setup
- Stick the starter and buzzer on a cardboard base.
- Keep the starter open/exposed, so it can sense heat from a flame.
- Use tape/glue to hold wires and parts neatly in place.
Step 3: Test the Model
- Ensure the circuit is connected but open (no current yet).
- Light a matchstick and bring it close to the starter for a few seconds.
- After heating, the starter closes its contacts, allowing current to flow → Buzzer sounds