JPS56116327A - Protection circuit for power transistor - Google Patents

Protection circuit for power transistor

Info

Publication number
JPS56116327A
JPS56116327A JP1996480A JP1996480A JPS56116327A JP S56116327 A JPS56116327 A JP S56116327A JP 1996480 A JP1996480 A JP 1996480A JP 1996480 A JP1996480 A JP 1996480A JP S56116327 A JPS56116327 A JP S56116327A
Authority
JP
Japan
Prior art keywords
current
transistor
contact
flows
relay coil
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
JP1996480A
Other languages
Japanese (ja)
Other versions
JPS6053486B2 (en
Inventor
Yusaku Matsubara
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 Electric Works Co Ltd
Original Assignee
Matsushita Electric Works 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 Works Ltd filed Critical Matsushita Electric Works Ltd
Priority to JP55019964A priority Critical patent/JPS6053486B2/en
Publication of JPS56116327A publication Critical patent/JPS56116327A/en
Publication of JPS6053486B2 publication Critical patent/JPS6053486B2/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage

Landscapes

  • Electronic Switches (AREA)

Abstract

PURPOSE:To make the device small and to low cost, by closing the contact to shorten a transistor, when an excessive current flows. CONSTITUTION:When a contact C1 is closed at the application of a switch, a transistor Q is on and the power supply voltage is fed to a load L, then the voltage of the current relay coil RY is increased and the base current IB flowing to the transistor Q flows to the point O via diodes D2 and D3. Thus, the current flowing to the transistor Q is saturated. After that, since the contact C2 of the current relay coil RY is closd, the current flowing to the circuit flows through the contact C2, and only small current flows between the collector and emitter of the transistor Q. When the circuit current becomes a normal value, the current relay coil RY is not activated, the contact C2 is opened, the circuit current flows to the collector and emitter of the transistor Q, and it is fed to the load L.
JP55019964A 1980-02-19 1980-02-19 power transistor protection circuit Expired JPS6053486B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55019964A JPS6053486B2 (en) 1980-02-19 1980-02-19 power transistor protection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55019964A JPS6053486B2 (en) 1980-02-19 1980-02-19 power transistor protection circuit

Publications (2)

Publication Number Publication Date
JPS56116327A true JPS56116327A (en) 1981-09-12
JPS6053486B2 JPS6053486B2 (en) 1985-11-26

Family

ID=12013871

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55019964A Expired JPS6053486B2 (en) 1980-02-19 1980-02-19 power transistor protection circuit

Country Status (1)

Country Link
JP (1) JPS6053486B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE449971B (en) * 1985-08-15 1987-06-01 Liftbyggarna Ab LINING TENSION DEVICE FOR LIFTING OR LINING SYSTEMS

Also Published As

Publication number Publication date
JPS6053486B2 (en) 1985-11-26

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