JPS6444790U

JPS6444790U -

Info

Publication number: JPS6444790U
Application number: JP13915487U
Authority: JP
Priority date: 1987-09-11
Filing date: 1987-09-11
Publication date: 1989-03-17

Description

[Brief explanation of the drawing]

第１図は本考案の一実施例の拡声装置の回路図
、第２図、第３図は本考案の別の実施例の拡声装
置を説明するための要部回路図、第４図は従来の
拡声装置の回路図を示す。１……通常ライン、２……緊急ライン、３……
共通ライン、４……増幅器、７……緊急スイツチ
、８……回線スイツチ、１０……出力制御器、１
１……スピーカ、１２……音量調節器、２１……
優先順位の高い入力（緊急入力回路）端子、２２
……優先順位の低い入力（非緊急入力回路）端子
。 FIG. 1 is a circuit diagram of a loudspeaker system according to an embodiment of the present invention, FIGS. 2 and 3 are circuit diagrams of main parts for explaining a loudspeaker system according to another embodiment of the present invention, and FIG. 4 is a conventional circuit diagram. A circuit diagram of a public address system is shown. 1...Normal line, 2...Emergency line, 3...
Common line, 4...Amplifier, 7...Emergency switch, 8...Line switch, 10...Output controller, 1
1...Speaker, 12...Volume adjuster, 21...
High priority input (emergency input circuit) terminal, 22
...Low priority input (non-emergency input circuit) terminal.

Claims

[Scope of utility model registration request]

In a public address system in which an amplifier and a speaker are connected by three-wire wiring consisting of a normal line, an emergency line, and a common line, the amplifier has two or more input terminals in order of priority, and the input terminal with the higher priority is provided with a means for controlling the emergency switch and outputting a broadcast signal to the emergency line when there is an input to the input terminal of the higher priority side, and controlling the emergency switch when there is an input to the input terminal of the higher priority side, and simultaneously controlling the emergency switch and outputting a broadcast signal to the input terminal of the lower priority side. A public address system characterized by comprising a circuit for attenuating.