JPS57165765A - Frequency detection system - Google Patents

Frequency detection system

Info

Publication number
JPS57165765A
JPS57165765A JP5343281A JP5343281A JPS57165765A JP S57165765 A JPS57165765 A JP S57165765A JP 5343281 A JP5343281 A JP 5343281A JP 5343281 A JP5343281 A JP 5343281A JP S57165765 A JPS57165765 A JP S57165765A
Authority
JP
Japan
Prior art keywords
input
alternating current
sampling
frequency
calculation
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
JP5343281A
Other languages
Japanese (ja)
Inventor
Makoto Suzuki
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.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP5343281A priority Critical patent/JPS57165765A/en
Publication of JPS57165765A publication Critical patent/JPS57165765A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
    • G01R23/02—Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Frequencies, Analyzing Spectra (AREA)

Abstract

PURPOSE:To make it possible to detect frequency of an input alternating current by conducting a specified calculation using three sampling voltages that are sampled from an alternating input. CONSTITUTION:Alternating current input v(t) is sampled with a specified period h by means of a sample holding circuit 8. After the voltage value of this sampling is A/D converted, it is supplied to the input circuit 10 of CPU. The calculation handling circuit 11 of CPU upon receiving the input performs calculation of the FormulaIby using three sampling voltage values to calculate frequency f of the alternating current input. The voltage values of the three samplings are the values of the samplings at the times, to-h, to, and to+h. In this way the frequency of input signal can be detected.
JP5343281A 1981-04-06 1981-04-06 Frequency detection system Pending JPS57165765A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5343281A JPS57165765A (en) 1981-04-06 1981-04-06 Frequency detection system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5343281A JPS57165765A (en) 1981-04-06 1981-04-06 Frequency detection system

Publications (1)

Publication Number Publication Date
JPS57165765A true JPS57165765A (en) 1982-10-12

Family

ID=12942677

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5343281A Pending JPS57165765A (en) 1981-04-06 1981-04-06 Frequency detection system

Country Status (1)

Country Link
JP (1) JPS57165765A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01298916A (en) * 1988-05-26 1989-12-01 Meidensha Corp Digital frequency relay
JPH02246725A (en) * 1989-03-15 1990-10-02 Hitachi Ltd Digital protective control device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5112166A (en) * 1974-07-22 1976-01-30 Tokyo Electric Power Co SHUHASUKEN SHUTSUHOSHIKI

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5112166A (en) * 1974-07-22 1976-01-30 Tokyo Electric Power Co SHUHASUKEN SHUTSUHOSHIKI

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01298916A (en) * 1988-05-26 1989-12-01 Meidensha Corp Digital frequency relay
JPH02246725A (en) * 1989-03-15 1990-10-02 Hitachi Ltd Digital protective control device

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