JPH0223181U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a telephone exchange system using an embodiment of the present invention, FIG. 2 is a circuit diagram of a telephone outlet of the same, and FIG. 3 is a circuit diagram of a main device of the same. 1 is the main device, 3 is the outside line, 4 is the doorphone slave unit, 5
1 is a telephone line, 6 is a signal line, 7 is an extension line, 8 is a telephone outlet, 10 is a telephone, 34 is a control circuit, and 35 is a door phone broadcast mode changeover switch.

Claims (1)

[Scope of utility model registration request] When a call is received from an external line, the telephone connected to the extension is connected to the external line, when a telephone connected to the extension calls the extension, the internal line is connected, and when a call is received from the doorphone slave, the telephone is connected to the extension. A main device that forms a communication path between the telephone line and the extension, respectively, and sends out a ring tone signal via the signal line when an extension is called or a door intercom slave device is called, and a telephone that connects the telephone to the extension from the main device. In a telephone exchange comprising at least a connecting means for connection, and a speaker connected to a signal line from a main device for notifying a ring tone signal, a door phone broadcast mode changeover switch in response to a door phone call;
When this broadcast mode change switch is set to the broadcast mode side, the call audio signal of the door intercom slave unit sent through the telephone line within a certain period of time from the time of a call from the door intercom slave unit is superimposed on the signal line and sent out. A telephone exchange characterized in that the main device is equipped with a doorphone simultaneous broadcast mode switching function.