JPS5871214U - Muting signal generation circuit - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【図面の簡単な説明】[Brief explanation of drawings]

第１図は従来のミューティング信号発生回路を示す回路
図、第２図はその特性図、第３図は本考案の一実施例を
示す回路図、第４図はその特性図、及び第５図は減電圧
特性を説明する為の特性図である。 主な図番の説明、９・・・電圧検出回路、１３゜１７・
・・定電流回路、２２・・・ダイオード。Fig. 1 is a circuit diagram showing a conventional muting signal generation circuit, Fig. 2 is a characteristic diagram thereof, Fig. 3 is a circuit diagram showing an embodiment of the present invention, Fig. 4 is a characteristic diagram thereof, and Fig. 5 is a circuit diagram showing a conventional muting signal generation circuit. The figure is a characteristic diagram for explaining the voltage reduction characteristics. Explanation of main drawing numbers, 9...Voltage detection circuit, 13°17.
... Constant current circuit, 22... Diode.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 電源投入時のショック音発生を防止する為のミューティ
ング信号を発生する回路であって、電源投入時に直ちに
第１の所定電位となる第１点の電位と、電源投入後所定
の時間を経過した後第１の所定電位よりも大なる第２の
所定電位となる第２点の電位とを比較して、電源投入か
ら一定時間が経過する迄の間、オン状態を保つトランジ
スタを含む電圧検出回路と、前記第１点の電位を安定に
保つ為の第１の定電流回路と、前記第２点の電位を安定
に保つ為の第２の定電流回路と、前記電圧検出回路の状
態に応じてミューティング信号を出力する出力端子と、
前記電圧検出回路と出力端子との間に挿入され、電源電
圧が低下した時オフとなる定電圧素子とから成るミュー
ティング信号発生回路。This is a circuit that generates a muting signal to prevent the generation of a shock sound when the power is turned on, and has a potential at a first point that becomes a first predetermined potential immediately when the power is turned on, and a muting signal that is set to a first predetermined potential when the power is turned on, and when a predetermined time has passed after the power is turned on. a voltage detection circuit including a transistor that maintains an on state for a certain period of time after power is turned on by comparing the potential at a second point with a second predetermined potential that is greater than the first predetermined potential; , a first constant current circuit for keeping the potential at the first point stable, a second constant current circuit for keeping the potential at the second point stable, and depending on the state of the voltage detection circuit. an output terminal that outputs a muting signal;
A muting signal generation circuit comprising a constant voltage element inserted between the voltage detection circuit and the output terminal and turned off when the power supply voltage drops.