JPS6489807A - Sound volume controller - Google Patents

Sound volume controller

Info

Publication number
JPS6489807A
JPS6489807A JP24646287A JP24646287A JPS6489807A JP S6489807 A JPS6489807 A JP S6489807A JP 24646287 A JP24646287 A JP 24646287A JP 24646287 A JP24646287 A JP 24646287A JP S6489807 A JPS6489807 A JP S6489807A
Authority
JP
Japan
Prior art keywords
sound volume
output
sawtooth wave
volume control
pwm converter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP24646287A
Other languages
Japanese (ja)
Inventor
Taro Funamoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP24646287A priority Critical patent/JPS6489807A/en
Publication of JPS6489807A publication Critical patent/JPS6489807A/en
Pending legal-status Critical Current

Links

Landscapes

  • Control Of Amplification And Gain Control (AREA)

Abstract

PURPOSE:To improve the sound volume change characteristic at a low sound volume by using an output pulse of a PWM converter so as to initialize the output of a sawtooth wave generating circuit to a zero value, smoothing the output of the sawtooth wave generating circuit so as to use it as a sound volume control voltage. CONSTITUTION:A PWM converter 1 generates a PWM signal being a pulse signal proportional to a sound volume control data. The sawtooth wave generating circuit 2 initializes the output to zero by using an output pulse of the PWM converter 1 and its output is a sawtooth wave signal synchronously with the output pulse of the PWM converter 1. A smoothing circuit 3 smooths the sawtooth wave signal to convert it into a sound control DC voltage. Thus, the sound volume control characteristic at a low sound volume is controlled optionally by using a sound volume control data and the sound volume control characteristic at low sound volume is improved by a simple circuit.
JP24646287A 1987-09-30 1987-09-30 Sound volume controller Pending JPS6489807A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP24646287A JPS6489807A (en) 1987-09-30 1987-09-30 Sound volume controller

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP24646287A JPS6489807A (en) 1987-09-30 1987-09-30 Sound volume controller

Publications (1)

Publication Number Publication Date
JPS6489807A true JPS6489807A (en) 1989-04-05

Family

ID=17148784

Family Applications (1)

Application Number Title Priority Date Filing Date
JP24646287A Pending JPS6489807A (en) 1987-09-30 1987-09-30 Sound volume controller

Country Status (1)

Country Link
JP (1) JPS6489807A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010056638A (en) * 2008-08-26 2010-03-11 Asahi Kasei Electronics Co Ltd Variable gain amplifying circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010056638A (en) * 2008-08-26 2010-03-11 Asahi Kasei Electronics Co Ltd Variable gain amplifying circuit

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