JPS59182607A - Pop noise preventing circuit of audio equipment - Google Patents

Pop noise preventing circuit of audio equipment

Info

Publication number
JPS59182607A
JPS59182607A JP58057300A JP5730083A JPS59182607A JP S59182607 A JPS59182607 A JP S59182607A JP 58057300 A JP58057300 A JP 58057300A JP 5730083 A JP5730083 A JP 5730083A JP S59182607 A JPS59182607 A JP S59182607A
Authority
JP
Japan
Prior art keywords
voltage
negative
power supply
pop noise
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
JP58057300A
Other languages
Japanese (ja)
Inventor
Ataru Shomura
Yoshihisa Hagiwara
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.)
NEC Home Electronics Ltd
NEC Corp
Original Assignee
NEC Home Electronics Ltd
Nippon Electric 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 NEC Home Electronics Ltd, Nippon Electric Co Ltd filed Critical NEC Home Electronics Ltd
Priority to JP58057300A priority Critical patent/JPS59182607A/en
Publication of JPS59182607A publication Critical patent/JPS59182607A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/30—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters
    • H03F1/305—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters in case of switching on or off of a power supply

Abstract

PURPOSE:To prevent pop noise by using a voltage dividing circuit connected between the positive and negative terminals of a power supply, a capacitor connected between the midpoint and ground, and a transistor(TR) whose base is connected to the midpoint and which discharges the negative power supply to ground through a resistor. CONSTITUTION:Since resistors R1 and R2 are selected so as to hold a base voltage of a TR4 zero while a main amplifier is actuated with a power supply turned on, the TR4 keeps inoperative. Although the operation of the main amplifier is stopped with a power switch turned off, since the voltage drop at positive side 101 of the power supply is faster than the negative side 102, a voltage is generated between the emitter and base of the TR4 thereby starting the operation of the TR4. The voltage at the negative side 102 is discharged through the resistor R3 and the TR4, the voltage rise is quickened by the share and the voltage curve is nearly coincident with the voltage drop curve of the positive side. As a result, since the final output stage of the amplifier is not held to the negative voltage, even if the power switch is turned on again, no pop noise is outputted from a speaker.
JP58057300A 1983-03-31 1983-03-31 Pop noise preventing circuit of audio equipment Pending JPS59182607A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP58057300A JPS59182607A (en) 1983-03-31 1983-03-31 Pop noise preventing circuit of audio equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP58057300A JPS59182607A (en) 1983-03-31 1983-03-31 Pop noise preventing circuit of audio equipment

Publications (1)

Publication Number Publication Date
JPS59182607A true JPS59182607A (en) 1984-10-17

Family

ID=13051699

Family Applications (1)

Application Number Title Priority Date Filing Date
JP58057300A Pending JPS59182607A (en) 1983-03-31 1983-03-31 Pop noise preventing circuit of audio equipment

Country Status (1)

Country Link
JP (1) JPS59182607A (en)

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