JPS5753109A - Protecting circuit for amplifier - Google Patents

Protecting circuit for amplifier

Info

Publication number
JPS5753109A
JPS5753109A JP55128735A JP12873580A JPS5753109A JP S5753109 A JPS5753109 A JP S5753109A JP 55128735 A JP55128735 A JP 55128735A JP 12873580 A JP12873580 A JP 12873580A JP S5753109 A JPS5753109 A JP S5753109A
Authority
JP
Japan
Prior art keywords
voltage
tr2a
current
tr34a
falls
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.)
Granted
Application number
JP55128735A
Other languages
Japanese (ja)
Other versions
JPS6057247B2 (en
Inventor
Shoji Fujikawa
Yoshihisa Suzuki
Tetsuo Wakamatsu
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.)
Nippon Gakki Co Ltd
Original Assignee
Nippon Gakki 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 Nippon Gakki Co Ltd filed Critical Nippon Gakki Co Ltd
Priority to JP55128735A priority Critical patent/JPS6057247B2/en
Publication of JPS5753109A publication Critical patent/JPS5753109A/en
Publication of JPS6057247B2 publication Critical patent/JPS6057247B2/en
Expired legal-status Critical Current

Links

Landscapes

  • Amplifiers (AREA)
  • Protection Of Static Devices (AREA)

Abstract

PURPOSE: To prevent the temperature from rising, by cutting off an excessive current when the excessive current is flowed to an output-stage transistor to generate an abnormal state.
CONSTITUTION: When conditions occur where an emitter current IE of a transistor TR2a is flowed over the limit value, a TR34a starts conduction, and the TR2a is turned off reversely. In this case, the voltage of a terminal 33 falls by reduction of the current IE, and the voltage between terminals 30a and 33 is increased according as the voltage of the terminal 33 falls; and therfore, the TR34a is saturated immediately, and the TR2a is turned off immediately. A circuit consisting of TRs 2b and 34b and a resistance 32b is operated similarly.
COPYRIGHT: (C)1982,JPO&Japio
JP55128735A 1980-09-17 1980-09-17 Amplifier protection circuit Expired JPS6057247B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55128735A JPS6057247B2 (en) 1980-09-17 1980-09-17 Amplifier protection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55128735A JPS6057247B2 (en) 1980-09-17 1980-09-17 Amplifier protection circuit

Publications (2)

Publication Number Publication Date
JPS5753109A true JPS5753109A (en) 1982-03-30
JPS6057247B2 JPS6057247B2 (en) 1985-12-13

Family

ID=14992150

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55128735A Expired JPS6057247B2 (en) 1980-09-17 1980-09-17 Amplifier protection circuit

Country Status (1)

Country Link
JP (1) JPS6057247B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5957016U (en) * 1982-10-08 1984-04-13 日本コロムビア株式会社 Amplifier output current limit circuit
JPS6062709A (en) * 1983-09-16 1985-04-10 Nf Kairo Sekkei Block:Kk Current limit circuit
WO1987000709A1 (en) * 1985-07-22 1987-01-29 Charters, John, Dumergue Composite audio amplifier

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5957016U (en) * 1982-10-08 1984-04-13 日本コロムビア株式会社 Amplifier output current limit circuit
JPS6062709A (en) * 1983-09-16 1985-04-10 Nf Kairo Sekkei Block:Kk Current limit circuit
WO1987000709A1 (en) * 1985-07-22 1987-01-29 Charters, John, Dumergue Composite audio amplifier

Also Published As

Publication number Publication date
JPS6057247B2 (en) 1985-12-13

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