| 摘要 |
In an apparatus for powering a television interphone monitor for communication between entrances of a building and individual apartment of the building, power is fed to the television interphone monitor which is operated by a rechargeable battery, through a transmission line which is of low cost. The apparatus includes a single entrance panel or a number of entrance panels each of which has a TV camera and a circuit for processing an electrical information signal which may include a video signal. One or a number of television interphone monitors are connected via respective transmission lines to power supply units which may be included in an entrance unit which is in turn connected to the entrance panels. The power supply units supply a regulated current to the rechargeable battery. The entrance unit also includes a circuit for feeding an information signal to the television interphone monitors and a circuit for receiving the information signal from the television interphone telephones through corresponding transmission lines. Switching circuits may be provided between the entrance unit and the television interphone monitors to connect any one of the monitors to one or another entrance panel.
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