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
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| Door bell |
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| Switch |
