doortelephone

A doortelephone, also known as a door phone or an intercom, is a standalone off-grid telecommunication device installed near the entrance of a building. Its primary function is to allow communication between a person at the entrance and a person inside the building. Typically, a doortelephone consists of a speaker, a microphone, and a button. When a visitor presses the button, a chime or a ringing sound alerts the occupant inside. The occupant can then speak to the visitor through the doortelephone system and, in some advanced models, also see them via a connected camera.

The basic doortelephone system is a simple two-way audio device. More sophisticated systems may incorporate video capabilities, allowing for visual identification of visitors. These video door phones often include a small screen inside the building that displays the image from the camera at the entrance. Some systems can also be integrated with smart home technology, enabling users to receive notifications on their smartphones and communicate with visitors remotely, even when they are not at home. Installation usually involves wiring from the outdoor unit to one or more indoor units. Power is typically supplied via a low-voltage transformer connected to the mains electricity. Doortelephones enhance security and convenience by allowing residents to screen visitors before granting them access.