JPS5597740A - Acoustic unit - Google Patents

Acoustic unit

Info

Publication number
JPS5597740A
JPS5597740A JP505979A JP505979A JPS5597740A JP S5597740 A JPS5597740 A JP S5597740A JP 505979 A JP505979 A JP 505979A JP 505979 A JP505979 A JP 505979A JP S5597740 A JPS5597740 A JP S5597740A
Authority
JP
Japan
Prior art keywords
power
circuit
power circuit
time constant
turned
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
JP505979A
Other languages
Japanese (ja)
Inventor
Masakazu Aya
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 JP505979A priority Critical patent/JPS5597740A/en
Publication of JPS5597740A publication Critical patent/JPS5597740A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/1607—Supply circuits

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
  • Noise Elimination (AREA)

Abstract

PURPOSE:To obtain an acoustic unit which never generates a noise after its power switch is turned OFF, even if a power circuit with a large time constant is used. CONSTITUTION:At a point closer to an AC power supply side than power circuit 4 large in time constant and between it and power switch 2, AC power is extracted and then rectified and smoothed by subordinate power circuit 14 with the time constant much smaller than that of power circuit 4. With power switch 2 OFF, a voltage rising rapidly can be obtained from subordinate power circuit 14 and a differential output of it is applied to the base of transistor Tr13. Then, one-shot multivibrator 11 is triggerd by the output of Tr13 to generate a muting pulse and Tr9A and Tr9B in muting circuit 7 are made to conduct, so that a noise generated when the power is turned OFF can be removed.
JP505979A 1979-01-19 1979-01-19 Acoustic unit Pending JPS5597740A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP505979A JPS5597740A (en) 1979-01-19 1979-01-19 Acoustic unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP505979A JPS5597740A (en) 1979-01-19 1979-01-19 Acoustic unit

Publications (1)

Publication Number Publication Date
JPS5597740A true JPS5597740A (en) 1980-07-25

Family

ID=11600817

Family Applications (1)

Application Number Title Priority Date Filing Date
JP505979A Pending JPS5597740A (en) 1979-01-19 1979-01-19 Acoustic unit

Country Status (1)

Country Link
JP (1) JPS5597740A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5056805A (en) * 1973-09-14 1975-05-17

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5056805A (en) * 1973-09-14 1975-05-17

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