JPS54147449A - Protective circuit - Google Patents

Protective circuit

Info

Publication number
JPS54147449A
JPS54147449A JP5595078A JP5595078A JPS54147449A JP S54147449 A JPS54147449 A JP S54147449A JP 5595078 A JP5595078 A JP 5595078A JP 5595078 A JP5595078 A JP 5595078A JP S54147449 A JPS54147449 A JP S54147449A
Authority
JP
Japan
Prior art keywords
transistor
load
base
approached
potential
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
JP5595078A
Other languages
Japanese (ja)
Inventor
Yasuo Taguchi
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.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura 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 Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP5595078A priority Critical patent/JPS54147449A/en
Publication of JPS54147449A publication Critical patent/JPS54147449A/en
Pending legal-status Critical Current

Links

Landscapes

  • Protection Of Static Devices (AREA)
  • Electronic Switches (AREA)

Abstract

PURPOSE: To prevent a damage to the load and ruin of the transistor which drives and controls the load by decreasing the potential at base and collector of the transistor which control the load transistor when the voltage applied to the load exceeds a specified value.
CONSTITUTION: When the DC output voltage applied to the integrated circuit 10 is made so high that it exceeds the voltage of Zener diode 16, a current flows in the resistances 17 and 18 connected with each other in series through the Zener diode 16. By this, base currents flow in the respective transistors 20, 22 the transistor 20 is approached to "on", the potential at base of the transistor 14 reduces and the transistor 14 is approached to "off". Also a base current flows in the transistor 22, which is approached to "on". Thus the potential at collector of the transistor 14 decreases. When the transistor 14 is not operated, the base current is not fed to the transistor 5 which is added to the integrated circuit 10 and drives the load 4, the transistor 5 is turned off. Therefore a damage to the load and the ruin of element can be prevented.
COPYRIGHT: (C)1979,JPO&Japio
JP5595078A 1978-05-11 1978-05-11 Protective circuit Pending JPS54147449A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5595078A JPS54147449A (en) 1978-05-11 1978-05-11 Protective circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5595078A JPS54147449A (en) 1978-05-11 1978-05-11 Protective circuit

Publications (1)

Publication Number Publication Date
JPS54147449A true JPS54147449A (en) 1979-11-17

Family

ID=13013346

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5595078A Pending JPS54147449A (en) 1978-05-11 1978-05-11 Protective circuit

Country Status (1)

Country Link
JP (1) JPS54147449A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5834599U (en) * 1981-08-31 1983-03-07 日本電気株式会社 protection circuit
JPH0253230U (en) * 1988-10-03 1990-04-17

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54141555A (en) * 1978-04-26 1979-11-02 Nec Corp Electric circuit

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54141555A (en) * 1978-04-26 1979-11-02 Nec Corp Electric circuit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5834599U (en) * 1981-08-31 1983-03-07 日本電気株式会社 protection circuit
JPH0323709Y2 (en) * 1981-08-31 1991-05-23
JPH0253230U (en) * 1988-10-03 1990-04-17

Similar Documents

Publication Publication Date Title
JPS57204629A (en) Control circuit of pulse width
JPS57172422A (en) Current supply source circuit
JPS54147449A (en) Protective circuit
JPS6439830A (en) A/d converter
GB2020504A (en) Transistor protection circuits
JPS5687119A (en) Switching regulator
JPS5448030A (en) Vercurrent protection circuit for swtching regulator
JPS57119514A (en) Flip-flop circuit
JPS5574614A (en) Short circuit protection circuit for constant voltage power supply
JPS5537879A (en) Transistor protection circuit
JPS564816A (en) Control circuit for transistor electric current
JPS558249A (en) Free wheeling circuit
JPS55110315A (en) Constant current circuit
JPS5472447A (en) Overcurrent protection of constant voltage circuit
JPS5697115A (en) Power supply device
JPS6489916A (en) Output protection device
JPS5445770A (en) Stabilized power supply
JPS559241A (en) Constant voltage circuit
JPS5668809A (en) Direct current power supply unit
JPS55131822A (en) Constant-voltage circuit
JPS55135916A (en) Constant-voltage circuit
JPS54108216A (en) Thyristor chopper circuit
JPS5523764A (en) Separately-excited dc-dc converter
JPS5697117A (en) Switching power supply device
JPS57182120A (en) Photocoupler device