| 摘要 |
<p>A local paging system is provided between telephone installations (11) in a building. The page signal is emitted by a buzzer (14) located in the centre of the dialling wheel of the handset. A central control unit (10) for the system comprises a make and break circuit (20) driven by power source (12) which distributes commands from hand set mounted switches (18) through intermediate stages (16), to the other hand sets.</p> |
