History of Doorbells
– William Murdoch invented the first mechanical doorbell in 1817.
– Joseph Henry’s scientific writings mention doorbells.
– Doorbells have been used for alerting and communicating with deaf and hard of hearing people.
– The Edwards Sylvan C-26 is a notable doorbell model.
Wired and Wireless Doorbells
– Wired doorbells have a button that activates a signaling device inside the building.
– The button connects to a transformer that steps down the voltage.
– Additional doorbell buttons can be connected to the system.
– Wireless doorbells use radio transmitters and receivers to send signals.
– Frequencies in the 2.4GHz ISM band are commonly used.
Musical and Continuous Power Doorbells
– Musical doorbells maintain power to play the doorbell song.
– Rectifier diode and ballast capacitor are used for simple doorbell buttons.
– Special doorbell buttons are used for mixed wireless and wired input doorbells.
– Continuous power is provided to the doorbell for other purposes.
Smart Doorbells
– Smart doorbells are internet-connected bell systems.
– Popular systems include Ring, Vivint Home Security, and Nest Hello.
– Smart doorbells have a high-definition camera, sensor, and Wi-Fi capability.
– Notifications are sent to paired smartphones or electronic devices.
– Video is recorded to a cloud internet service for analysis and security purposes.
Doorbells for Deaf and Hard of Hearing People
– Doorbells have been adapted for alerting and communicating with deaf and hard of hearing individuals.
– Specialized doorbells have improved accessibility.
– Information on available devices can be found on the Clerccenter.gallaudet.edu website.
– NPR covered the topic in an article titled ‘At Gallaudet, a Turn Inward Opens New Worlds.’ Source: https://en.wikipedia.org/wiki/Doorbell
A doorbell is a signaling device typically placed near a door to a building's entrance. When a visitor presses a button, the bell rings inside the building, alerting the occupant to the presence of the visitor. Although the first doorbells were mechanical, activated by pulling a cord connected to a bell, modern doorbells are electric, operated by a pushbutton switch. Modern doorbells often incorporate intercoms and miniature video cameras to increase security.
