JPS54118547A - Transistor circuit with protection circuit - Google Patents

Transistor circuit with protection circuit

Info

Publication number
JPS54118547A
JPS54118547A JP2514978A JP2514978A JPS54118547A JP S54118547 A JPS54118547 A JP S54118547A JP 2514978 A JP2514978 A JP 2514978A JP 2514978 A JP2514978 A JP 2514978A JP S54118547 A JPS54118547 A JP S54118547A
Authority
JP
Japan
Prior art keywords
transistor
voltage
protection
output transistor
circuit
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
JP2514978A
Other languages
Japanese (ja)
Inventor
Haruhiko Nozaki
Hiroaki Shimizu
Masahiko Nakajima
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 JP2514978A priority Critical patent/JPS54118547A/en
Publication of JPS54118547A publication Critical patent/JPS54118547A/en
Pending legal-status Critical Current

Links

Landscapes

  • Emergency Protection Circuit Devices (AREA)

Abstract

PURPOSE: To prevent the destruction of output transistor due to the anomaly of power voltage by interrupting the output transistor by the constant monitoring of power voltage when the voltage exceeds predetermined voltage.
CONSTITUTION: The collector of the transistor 4 for protection is connected to the base of the output transistor 2, and the emitter of the transistor for protection is connected to the emitter of the output transistor. And, the constant voltage diode 5 is connected in the reverse direction to between the power source Vcc and the base of the transistor 4 for protection and voltage is set up so that the sum of the voltae between the base and emitter of the transistor 4 for protection and the Zener voltage of the constant voltage diode 5 is higher than the volgage of power source. Thus, when the power voltage exceeds the specified value, trans-loaded output transistor is interrupted, thus protecting the output transistor from destruction.
COPYRIGHT: (C)1979,JPO&Japio
JP2514978A 1978-03-06 1978-03-06 Transistor circuit with protection circuit Pending JPS54118547A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2514978A JPS54118547A (en) 1978-03-06 1978-03-06 Transistor circuit with protection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2514978A JPS54118547A (en) 1978-03-06 1978-03-06 Transistor circuit with protection circuit

Publications (1)

Publication Number Publication Date
JPS54118547A true JPS54118547A (en) 1979-09-14

Family

ID=12157936

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2514978A Pending JPS54118547A (en) 1978-03-06 1978-03-06 Transistor circuit with protection circuit

Country Status (1)

Country Link
JP (1) JPS54118547A (en)

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