how does a Door bell work

A doorbell is a signaling device placed near a door to a buildings entrance. doorbell make life much easier. with a simple push of a button ,friends, family member can announce their presence outside the door.

First doorbells were mechanical , nowadays we have electrical doorbells operated by push-button switch.

how does a Door bell works

wired and wireless

wired mechanism  

When switch is pressed , which is present near the door activates a signaling device (bell or buzzer).

when switch is pressed it closes the doorbell circuit. one terminal is connected to transformer . A doorbell transformer steps down the 240 V to (5 to 20) V, another terminal is connected to signalling device which produces voice.

The heart of a doorbell is electromagnet. doorbell uses the magnetic field created by the electromagnet to move a magnetic piston to strike two tone bars.

Wireless mechanism

Doorbell button contains radio transmitter powered by a battery.

when button is pressed radio signal is detected by the receiver, it activates a sound chip and play the music.

Frequencies used is 2.4 GHz ISM band.he

Mechanical bell

Previous days we used to see mechanical bell .

if we pull the rod connected to bell, we can hear the voice.

Future door bell 

Sensors will be made used to sense object in-front of door and activate the signal. It helps in security of the house also, if someone wants to enter home without permission.

Few pictures for reference 

 Door bell

Switch 

Even in simple device like door bell electronics is made used, and made our life easier.