JPS5530209A - Surge protection circuit - Google Patents

Surge protection circuit

Info

Publication number
JPS5530209A
JPS5530209A JP10271278A JP10271278A JPS5530209A JP S5530209 A JPS5530209 A JP S5530209A JP 10271278 A JP10271278 A JP 10271278A JP 10271278 A JP10271278 A JP 10271278A JP S5530209 A JPS5530209 A JP S5530209A
Authority
JP
Japan
Prior art keywords
voltage
emitter
transistor
circuit
base
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
JP10271278A
Other languages
Japanese (ja)
Inventor
Ritsuji Takeshita
Kunio Seki
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP10271278A priority Critical patent/JPS5530209A/en
Publication of JPS5530209A publication Critical patent/JPS5530209A/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 obtain a surge protiction circuit which protects collector-emitter dielectric strength under a constant dielectric-strength voltage by applying a reverse bias between the base and emitter of an output-stage transistor in protective operation. CONSTITUTION:For the surge protection of output-stage transistors Q1 and Q2, surge-voltage detection circuit 1 is provided which consists of transistor Q14 applied at its base with the Zener voltage of constant-voltage circuit Z. R5 as a reference voltage, voltage-dividing resistances R9 and R10 applying the divided voltage of power voltage Vcc to the emitter, and collector load resistance R11. When the divided voltage output of a fixed voltage higher than power voltage Vcc and less than the deilectric strength of the transistor exceeds the Zener voltage in this circuit, transistor Q14 turns ON to develop a voltage signal at the collector. This signal drives and controls transistors at stages following this so as to apply a reverse bias between the base and emitter of transistors Q1 and Q2, thereby obtaining a large dielectric strength voltage.
JP10271278A 1978-08-25 1978-08-25 Surge protection circuit Pending JPS5530209A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10271278A JPS5530209A (en) 1978-08-25 1978-08-25 Surge protection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10271278A JPS5530209A (en) 1978-08-25 1978-08-25 Surge protection circuit

Publications (1)

Publication Number Publication Date
JPS5530209A true JPS5530209A (en) 1980-03-04

Family

ID=14334873

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10271278A Pending JPS5530209A (en) 1978-08-25 1978-08-25 Surge protection circuit

Country Status (1)

Country Link
JP (1) JPS5530209A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63133829A (en) * 1986-11-21 1988-06-06 日本電気アイシーマイコンシステム株式会社 Power amplifying circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5081248A (en) * 1973-11-16 1975-07-01

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5081248A (en) * 1973-11-16 1975-07-01

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63133829A (en) * 1986-11-21 1988-06-06 日本電気アイシーマイコンシステム株式会社 Power amplifying circuit

Similar Documents

Publication Publication Date Title
JPS5753112A (en) Sepp power amplifier
ES405172A1 (en) Drive circuit for conducting devices
JPS5530209A (en) Surge protection circuit
WO1979000714A1 (en) Motor speed controlling circuit
JPS5688513A (en) Constant-current driving circuit
ES444642A1 (en) Logic driver circuit with output protection
GB845092A (en) Improvements in or relating to signal amplifier circuits employing transistors
KR910003888A (en) Protection circuit against negative excess voltage applied to the power supply of the integrated circuit including the power device associated with the control circuit
GB1467649A (en) Electronic amplifier
JPS5619210A (en) Wave detecting circuit
SU432476A1 (en) DEVICE FOR PROTECTION FROM OVERLOAD POWER SUPPLY OF DC POWER
JPS5710815A (en) Biasing circuit
JPS55161975A (en) Effective value circuit of glow plug
JPS56168243A (en) Constant-voltage circuit
JPS5568734A (en) Switching device
JPS5688515A (en) Constant-voltage power source circuit
JPS5614724A (en) Switch circuit
JPS57133707A (en) Bias circuit for power amplifier
JPS56114436A (en) Power transistor driving circuit
JPS5616311A (en) Transistor circuit
JPS5515511A (en) Constant current circuit
JPS559241A (en) Constant voltage circuit
JPS5550712A (en) Protection circuit for single ended push pull amplifier
JPS55131822A (en) Constant-voltage circuit
JPS5621071A (en) Signal level indicator