| 摘要 |
PURPOSE: A switching apparatus for a lobby phone is provided to connect a lobby phone and a house phone using some part of a telephone line. CONSTITUTION: A lobby phone connection unit(12) switches the connection of the lobby phone(10). A call signal generator(14) generates the call signal of the lobby phone. A switching relay(16) switches a house phone(50) which is currently connected with a public telephone line(40) to the lobby phone. A circuit monitoring unit(18) monitors communication between the house phone through the telephone line. If a call signal from the lobby phone is generated, a switching control unit(28) controls the operation of the switching relay in order to call the corresponding house phone. |
