A fire alarm is a an electronic sounder or a bell. The sounder makes a loud high pitched sound to alert people that there is a fire in the building.Here the fire alarm devices senses the heat and activates the loud noise .
Now I am going to instruct how to make a fire alarm with less number of components.
Lets Get Started..
Step 1: Components Required
Piezo buzzer - 1 [Banggood]
9V Battery & Snap - 1 [Banggood]
PCB -1 [Banggood]
Fluorescent light starter - 1
You can get other tools and components : [Banggood]
Step 2: Circuiting
First remove the case of fluorescent light starter and then remove the capacitor form it.
Connect positive terminal of the battery to the positive terminal of piezo buzzer.
Negative pin of piezo buzzer goes to any one of the pin of tube light starter.
Another pin of Starter goes to negative pin of the battery.
Here circuiting is completed.
You can watch the video below for further any clarifications of the circuiting.
Here in the circuit the starter acts as the switch. When the bulb is heated, it acts closed switch. When it cools it acts as open switch.