DOORBELLS

A doorbell is...

a bell chimb connected to a door, rung by someone outside wanting someone inside to open the door.

WE WILL MAKE A Circuit DOORBEL USING:

• a basic stamp board
• a buzzer
• 9V battery
• push button
• a wire

HOW IT WORKS

Doorbells are electromagnets. Electromagnets are coils of wire wrapped around a piece of magnetic metal. When you press the bell, it completes the electrical circuit; the magnetic field is used to power the bell sound.

For a simple chime doorbell...

it uses the magnetic field, created by the electromagnet, to move the magnet piston. Striking the tone bars creating the "ding dong" sound.

For a buzzer...

the circuit closes when the button is pressed. The electromagnet moves the contact arm. When the arm moves, it interupts the current, stopping the electromagnet. If held down, the chime repeats over and over.

WHY OUR CIRCUIT WORKS

The energy moves from the battery, through the first wire to the row connecting to the corner of the button. The energy can only move through it if the button is pressed. It allows the energy to continue through the buzzer, making the sound.

NOT PRESSED

PRESSED