JPS5780812A - Amplifier with protection function for output short- circuit - Google Patents

Amplifier with protection function for output short- circuit

Info

Publication number
JPS5780812A
JPS5780812A JP55156508A JP15650880A JPS5780812A JP S5780812 A JPS5780812 A JP S5780812A JP 55156508 A JP55156508 A JP 55156508A JP 15650880 A JP15650880 A JP 15650880A JP S5780812 A JPS5780812 A JP S5780812A
Authority
JP
Japan
Prior art keywords
dotted line
output
current
npn
short
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
JP55156508A
Other languages
Japanese (ja)
Inventor
Akira Yamagishi
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 Corp
Original Assignee
NEC Corp
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 Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP55156508A priority Critical patent/JPS5780812A/en
Publication of JPS5780812A publication Critical patent/JPS5780812A/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
    • H03F1/52—Circuit arrangements for protecting such amplifiers

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)

Abstract

PURPOSE:To protect an output transistor at an output short-circuited time without external elements and with a minimum increment of elements. CONSTITUTION:In the normal operation time when an output terminl is not short-circuited, a normal amplifying operation is performed. When connection point (a) is short-circuited to the earth point, electric charge stored in a capacitor 17 is discharged along a dotted line (c) as well as a dotted line (b) simultaneously. By this discharging along the dotted line (b), an NPN transistor TR24 is turned on, and a PNP TR21 is turned on also. Turning-on of the PNP TR21 and the NPN TR24 continues by the thyristor effect unless the power source is turned off. A current limited by resistances 22 and 23 is flowed as the base current of the NPN output TR25 to limit the current of the dotted line (c) to a current obtained by multiplying the base current by the gain. As a result, the current of the dotted line (c) does not become infinite to protect the NPN output TR25 from breakdown.
JP55156508A 1980-11-07 1980-11-07 Amplifier with protection function for output short- circuit Pending JPS5780812A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55156508A JPS5780812A (en) 1980-11-07 1980-11-07 Amplifier with protection function for output short- circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55156508A JPS5780812A (en) 1980-11-07 1980-11-07 Amplifier with protection function for output short- circuit

Publications (1)

Publication Number Publication Date
JPS5780812A true JPS5780812A (en) 1982-05-20

Family

ID=15629290

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55156508A Pending JPS5780812A (en) 1980-11-07 1980-11-07 Amplifier with protection function for output short- circuit

Country Status (1)

Country Link
JP (1) JPS5780812A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002343647A (en) * 2001-05-16 2002-11-29 Mitsubishi Electric Corp Three-phase wound core

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002343647A (en) * 2001-05-16 2002-11-29 Mitsubishi Electric Corp Three-phase wound core

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