JPS61264891A - Key telephone set - Google Patents

Abstract

PURPOSE:To automatically set the appropriate levels of calls between a trunk line and a key telephone set, and between key telephone sets by amplifying variably a sound signal that is a signal converted from a channel converted with a two line-four line conversion. CONSTITUTION:During the call between the trunk line 170 and a key telephone set 160, signals from a trunk line interface part 110 and a key telephone set interface part 120 are detected by a control circuit 150 and the gains of variable amplifier circuits 122 and 123 are raised to the appropriate levels by the detected signals. On the other hand, during the call between key telephone sets 160 and 161, the signals from key telephone set interface parts 120 and 130 are detected by the circuit 150 and the gains of variable amplifier circuits 122 and 123 or 132 and 133 are lowered to the appropriate levels by the detected signals. Thus, at the circuits 122, 123, 132 and 133, the gains are controlled so as to output the sound signal of appropriate level by the circuit 150.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a button telephone device, and in particular to a button that can automatically set the conversation level with a central office line and the conversation level between key telephones to appropriate levels. Relating to telephone devices.

[Conventional technology]

Conventionally, button telephone devices include a button telephone and a main device that connects the central office line and the button telephones or each other. , there was a level difference.

[Problem that the invention seeks to solve]

In the conventional key telephone device described above, the central office line and the telephone line of the key telephone are connected as two wires, so the telephone signal cannot be amplified within the main device, and the gain or loss during the telephone call is Both sending and receiving calls are determined uniquely. Therefore, there was a problem in that the communication level with the central office line was low and the communication level between the key telephones was high, which hindered communication.

[Means for solving problems]

The button telephone device of the present invention has a telephone interface section that accommodates a connection line of a button telephone, a central office line interface section that accommodates a central office line, and a telephone interface section that performs a connection including a central office line, a central office line, and a mutual connection between the button telephone and the central telephone. A button telephone device comprising a path switch section, a control circuit for controlling the telephone interface section, the central office line interface section, and the call path switch section, wherein a connection line of the button telephone is converted into two wires and four wires. The control circuit includes a 4-wire conversion circuit, a variable amplification circuit that variably amplifies each converted signal, and a 2-4 wire conversion circuit that converts the office line into 2-4 wires, The present invention is characterized in that the gain of the variable amplifier circuit is lowered to an appropriate level during a call, and the gain of the variable amplifier circuit is increased to an appropriate level while the button telephone is communicating with the office line.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

The figure is a block diagram of an embodiment of the invention.

The key telephone device of this embodiment includes a main device 100 and key telephones 160 and 161. The main device 100 includes a central office line interface section 110, telephone interface sections 120 and 130, a communication path switch section 140, and a control circuit 150.
includes a 2-wire 4-wire conversion circuit 111 connected to the station 111170, and telephone interface sections 120 and 130 include 2-wire 4-wire conversion circuits 121 and 131 connected to key telephones 160 and 161, respectively, and variable amplifier circuits 122 and 123.
．． It has variable amplification circuits 132 and 133. The communication path switch section 140 is connected to each interface section and 4? Connected by #lA audio line. Further, the control circuit 150 is a button telephone 16o.

161 data lines 1601, 1611 and telephone interface sections 120, 130, and controls each section within the main device according to information on pressing various buttons.

Next, the operation of this embodiment device will be explained.

The station #170 and the button telephone 160 are connected to the 2-wire 4M conversion circuit 111 of the station line interface section 110, the communication path switch section 140, the variable amplifier circuits 122 and 123,
During a call via the 2-wire 4-wire conversion circuit 121, the control circuit 150 detects signals from the office line interface section 110 and the telephone interface section 120, and uses the detected signals to control the variable amplifier circuit 122 and the telephone interface section 120. Increase the gain of 123 to an appropriate level.

Next, the button telephone 160 and the button telephone 161
2-wire 4-wire conversion circuit 1 of telephone interface unit 120
21, variable amplifier circuits 122 and 123, communication path switch section 140, variable amplifier circuits 132 and 133,
During a call via the line 4M conversion circuit 131, the control circuit 150 detects signals from the telephone interface units 120 and 130, and the detected signals are used to control the variable amplifier circuits 122 and 123 or the variable amplifier circuit 132. and 13
Reduce the gain of 3 to an appropriate level. In this way, the variable gain amplifier circuits 122, 123, 132, 133 are connected to the control circuit 1.
50 controls the gain so as to output an audio signal at an appropriate level.

〔Effect of the invention〕

As explained above, the present invention converts the call path into two or four wires within the main device and variably amplifies the converted audio signals, thereby adjusting the call level between the office line and the key telephone, and the communication between the key telephones. This has the effect of automatically setting the call level to an appropriate level.

[Brief explanation of the drawing] The drawing is a block diagram showing one embodiment of the present invention.

Claims (1)

Claims: The main device includes a button telephone and a main device, wherein the main device includes a telephone interface section for accommodating a connection line of the button telephone, a central office line interface section for accommodating a central office line, the button telephone and the main device. A button telephone device comprising: a communication path switch section that performs connections including connections between a central office line and the button telephone; and a control circuit that controls the telephone interface section, the central office line interface section, and the communication path switch section, The main device further includes a first 2-wire/4-wire conversion circuit that converts the connection line of the key telephone to 2-wire/4-wire;
The control circuit includes a second 2-wire 4-wire conversion circuit that performs wire-to-4 wire conversion, and a variable amplification circuit that variably amplifies the signal converted by the first 2-wire 4-wire conversion circuit, and the control circuit A key telephone device characterized in that the gain of the variable amplifier circuit is lowered to an appropriate level during a mutual call, and the gain of the variable amplifier circuit is increased to an appropriate level while the key telephone is communicating with the central office line.