JPS54119645A - Power failure detection circuit - Google Patents

Power failure detection circuit

Info

Publication number
JPS54119645A
JPS54119645A JP2542778A JP2542778A JPS54119645A JP S54119645 A JPS54119645 A JP S54119645A JP 2542778 A JP2542778 A JP 2542778A JP 2542778 A JP2542778 A JP 2542778A JP S54119645 A JPS54119645 A JP S54119645A
Authority
JP
Japan
Prior art keywords
voltage
power failure
failure detection
power
commercial power
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
JP2542778A
Other languages
Japanese (ja)
Inventor
Naoki Furuhashi
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 JP2542778A priority Critical patent/JPS54119645A/en
Publication of JPS54119645A publication Critical patent/JPS54119645A/en
Pending legal-status Critical Current

Links

Landscapes

  • Measurement Of Current Or Voltage (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

PURPOSE: To prevent the variation in a power failure level due to that in frequency and quickly supply a power failure detection signal, by providing a means for detecting the drastic voltage fall of commercial power and a means for detecting the slow voltage fall thereof.
CONSTITUTION: The voltage of the commercial power 1 is dropped by a transformer 2 and then applied to a DC stabilization circuit 4 to supply a DC voltage to a data processor 2 etc. The dropped voltage of the power is also applied to a rectifier circuit 3 to supply a DC voltage to a power failure detection circuit consisting of two comparator circuits 10, 10', two reference voltages 8, 9 and two capacitors 5, 6. The capacitance of the capacitor 5 is set low so that its terminal voltage quickly varies in response to the voltage change of the commercial power 1. The capacitance of the capacitor 6 is set high so that its terminal voltage slowly varies in response to the voltage change of the commercial power 1. The terminal voltages of the capacitors 5, 6 are compared with the reference voltages 8, 9, respectively. Thus, the power failure detection level is kept constant independently of the frequency. This results in always stable detection of power failure.
COPYRIGHT: (C)1979,JPO&Japio
JP2542778A 1978-03-08 1978-03-08 Power failure detection circuit Pending JPS54119645A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2542778A JPS54119645A (en) 1978-03-08 1978-03-08 Power failure detection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2542778A JPS54119645A (en) 1978-03-08 1978-03-08 Power failure detection circuit

Publications (1)

Publication Number Publication Date
JPS54119645A true JPS54119645A (en) 1979-09-17

Family

ID=12165657

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2542778A Pending JPS54119645A (en) 1978-03-08 1978-03-08 Power failure detection circuit

Country Status (1)

Country Link
JP (1) JPS54119645A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56140264A (en) * 1980-04-03 1981-11-02 Chino Works Ltd Detecting circuit of power interruption and recovery thereof
JPS59206773A (en) * 1983-05-11 1984-11-22 Tohoku Oki Denki Kk Circuit for detecting abnormality of ac power supply
JPS6335122A (en) * 1986-07-28 1988-02-15 日本ケミコン株式会社 Interruption detector of electric source

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56140264A (en) * 1980-04-03 1981-11-02 Chino Works Ltd Detecting circuit of power interruption and recovery thereof
JPS59206773A (en) * 1983-05-11 1984-11-22 Tohoku Oki Denki Kk Circuit for detecting abnormality of ac power supply
JPS6335122A (en) * 1986-07-28 1988-02-15 日本ケミコン株式会社 Interruption detector of electric source

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