JPS6488372A - Current detecting device - Google Patents

Current detecting device

Info

Publication number
JPS6488372A
JPS6488372A JP62248734A JP24873487A JPS6488372A JP S6488372 A JPS6488372 A JP S6488372A JP 62248734 A JP62248734 A JP 62248734A JP 24873487 A JP24873487 A JP 24873487A JP S6488372 A JPS6488372 A JP S6488372A
Authority
JP
Japan
Prior art keywords
circuit
output
current
amplified
sent
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
JP62248734A
Other languages
Japanese (ja)
Inventor
Yoshihiro Nagano
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.)
Shimadzu Corp
Original Assignee
Shimadzu 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 Shimadzu Corp filed Critical Shimadzu Corp
Priority to JP62248734A priority Critical patent/JPS6488372A/en
Publication of JPS6488372A publication Critical patent/JPS6488372A/en
Pending legal-status Critical Current

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  • Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)

Abstract

PURPOSE:To obtain an exact current detection output by bringing the gain of an amplifier to negative feedback control by the mean value of an electrical signal obtained by converting a light modulated by a current. CONSTITUTION:The light from a light source 1 is sent to a magneto-optical modulating element 3 through an optical fiber 2, and an output light of the element 3 passes through an optical fiber 4 and sent to a photodiode 5, and converted to an electric signal. This electric signal is converted to a voltage signal by a current-voltage converting circuit 6, and thereafter, amplified by a variable gain amplifying circuit 7. The output of this circuit 7 is amplified by an AC amplifying circuit 8 and outputted as a current detection output. Also, the output of the circuit 7 is sent to a DC amplifying circuit 9 and its DC component is amplified, and this DC component is compared with a reference level in a differential amplifying circuit 10, and an output corresponding to their difference is obtained. Subsequently, the output of the circuit 10 is inputted to a gain control terminal of the circuit 7. That is, a negative feedback circuit is formed by the circuits 9, 10 and the output of the circuit 7 is brought to negative feedback control so that a prescribed DC component is always outputted. Accordingly, an AC signal reflecting exactly an AC current is obtained.
JP62248734A 1987-09-30 1987-09-30 Current detecting device Pending JPS6488372A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62248734A JPS6488372A (en) 1987-09-30 1987-09-30 Current detecting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62248734A JPS6488372A (en) 1987-09-30 1987-09-30 Current detecting device

Publications (1)

Publication Number Publication Date
JPS6488372A true JPS6488372A (en) 1989-04-03

Family

ID=17182564

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62248734A Pending JPS6488372A (en) 1987-09-30 1987-09-30 Current detecting device

Country Status (1)

Country Link
JP (1) JPS6488372A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01276074A (en) * 1988-04-28 1989-11-06 Mitsubishi Cable Ind Ltd Optical demodulator
JP2011033501A (en) * 2009-08-03 2011-02-17 Seikoh Giken Co Ltd Electric field, magnetic field and voltage detector with feedback circuit
JP2011191107A (en) * 2010-03-12 2011-09-29 Seikoh Giken Co Ltd Optical transmission device including multichannel rotary joint

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01276074A (en) * 1988-04-28 1989-11-06 Mitsubishi Cable Ind Ltd Optical demodulator
JP2011033501A (en) * 2009-08-03 2011-02-17 Seikoh Giken Co Ltd Electric field, magnetic field and voltage detector with feedback circuit
JP2011191107A (en) * 2010-03-12 2011-09-29 Seikoh Giken Co Ltd Optical transmission device including multichannel rotary joint

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