JPS57191564A - Electric current value discriminating circuit - Google Patents

Electric current value discriminating circuit

Info

Publication number
JPS57191564A
JPS57191564A JP7780281A JP7780281A JPS57191564A JP S57191564 A JPS57191564 A JP S57191564A JP 7780281 A JP7780281 A JP 7780281A JP 7780281 A JP7780281 A JP 7780281A JP S57191564 A JPS57191564 A JP S57191564A
Authority
JP
Japan
Prior art keywords
voltage
capacitor
diode
comparator
resistance
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
JP7780281A
Other languages
Japanese (ja)
Inventor
Seiichi Uyama
Yoshinori Suzuki
Hiroyuki Tateishi
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 JP7780281A priority Critical patent/JPS57191564A/en
Publication of JPS57191564A publication Critical patent/JPS57191564A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/16571—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Current Or Voltage (AREA)

Abstract

PURPOSE:To discriminate a load current value accurately without reference to fluctuation in AC frequency by dividing an AC voltage by a capacitor and a resistance, and then using the output, obtained by rectifying and smoothing said divided voltage, as a reference voltage. CONSTITUTION:The voltage induced across a current transformer 8 according to the current flowing through the load 4 between terminals 1 and 2 is rectified and smoothed by a diode 9, a capacitor 10 and a resistance 11 and then inputted as a comparison input voltage V1 to a comparator 12. The commercial AC voltage between lines 3 and 5, on the other hand, is divided by a capacitor 13 and a resistance 14, and rectified and smoothed by a diode 15 and a capacitor 16, and the divided voltage obtained through voltage dividing resistances 17 and 18 is inputted as a reference input voltage v2 to the comparator 12. The output of the comparator 12 is supplied to a light emitting diode 7 connected to a DC power source circuit 20, and the diode 7 turns on when V1>V2. Consequently, the reference voltage varies with the fluctuation of frequency to compensate the variation in conversion rate of the current transformer.
JP7780281A 1981-05-21 1981-05-21 Electric current value discriminating circuit Pending JPS57191564A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7780281A JPS57191564A (en) 1981-05-21 1981-05-21 Electric current value discriminating circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7780281A JPS57191564A (en) 1981-05-21 1981-05-21 Electric current value discriminating circuit

Publications (1)

Publication Number Publication Date
JPS57191564A true JPS57191564A (en) 1982-11-25

Family

ID=13644131

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7780281A Pending JPS57191564A (en) 1981-05-21 1981-05-21 Electric current value discriminating circuit

Country Status (1)

Country Link
JP (1) JPS57191564A (en)

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