JPS55131781A - Frequency detector - Google Patents

Frequency detector

Info

Publication number
JPS55131781A
JPS55131781A JP3962079A JP3962079A JPS55131781A JP S55131781 A JPS55131781 A JP S55131781A JP 3962079 A JP3962079 A JP 3962079A JP 3962079 A JP3962079 A JP 3962079A JP S55131781 A JPS55131781 A JP S55131781A
Authority
JP
Japan
Prior art keywords
cos
data
voltage
frequency
memorized
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
JP3962079A
Other languages
Japanese (ja)
Inventor
Yoshihiro Kawasaki
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.)
Meidensha Electric Manufacturing Co Ltd
Original Assignee
Meidensha Electric Manufacturing 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 Meidensha Electric Manufacturing Co Ltd filed Critical Meidensha Electric Manufacturing Co Ltd
Priority to JP3962079A priority Critical patent/JPS55131781A/en
Publication of JPS55131781A publication Critical patent/JPS55131781A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To accomplish higher accuracy and higher speed by conducting a comparison, calculation and checking employing several sampling data and settling values in the determination of frequency computed with an aid of data digitalized obtained from the sampling of voltage in the power system.
CONSTITUTION: AC voltage 1 is inputted into a sample hold circuit 2 whose output is converted into a digital data with an AD converter whereby sampling data ViW Vi+4 is memorized in the input data memory 4A. The arithmetic section 11A performs a processing to compute cos 2ϕ, namely, (Vi 2-Vi+4 2)/2(Vi+1 2-Vi+3 2) and Vi+1 2-Vi+3 2=0 is determined by the comparator 14A. When Yes is given, outputted is the frequency which has been memorized in the output data memory circuit 14A immediately before the inputting of the voltage 1. On the other hand, when No is given, after the computation of cos 2ϕ in the arithmetic section 11A, the memorized value of cos 2ϕ is readout from the memory circuit 12A to check whether it coincides the result of the computation by means of the coincidence circuit 9A. When the coincidence signal is detected, the frequency f corresponding to cos 2ϕ thus computed is outputted from the gates 13A and 15A.
COPYRIGHT: (C)1980,JPO&Japio
JP3962079A 1979-04-02 1979-04-02 Frequency detector Pending JPS55131781A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3962079A JPS55131781A (en) 1979-04-02 1979-04-02 Frequency detector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3962079A JPS55131781A (en) 1979-04-02 1979-04-02 Frequency detector

Publications (1)

Publication Number Publication Date
JPS55131781A true JPS55131781A (en) 1980-10-13

Family

ID=12558146

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3962079A Pending JPS55131781A (en) 1979-04-02 1979-04-02 Frequency detector

Country Status (1)

Country Link
JP (1) JPS55131781A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4633516A (en) * 1985-05-30 1986-12-30 United States Of America As Represented By The Secretary Of The Air Force Instantaneous frequency measurement receiver with digital processing

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4633516A (en) * 1985-05-30 1986-12-30 United States Of America As Represented By The Secretary Of The Air Force Instantaneous frequency measurement receiver with digital processing

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