JPS55113383A - Light receiving circuit - Google Patents

Light receiving circuit

Info

Publication number
JPS55113383A
JPS55113383A JP2009579A JP2009579A JPS55113383A JP S55113383 A JPS55113383 A JP S55113383A JP 2009579 A JP2009579 A JP 2009579A JP 2009579 A JP2009579 A JP 2009579A JP S55113383 A JPS55113383 A JP S55113383A
Authority
JP
Japan
Prior art keywords
amplifier amp
component
circuit
discriminant
photodetector
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
JP2009579A
Other languages
Japanese (ja)
Inventor
Yoshitsugu Yamanashi
Yasuhiro Tanaka
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.)
Fujitsu Ltd
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP2009579A priority Critical patent/JPS55113383A/en
Publication of JPS55113383A publication Critical patent/JPS55113383A/en
Pending legal-status Critical Current

Links

Landscapes

  • Light Receiving Elements (AREA)
  • Optical Communication System (AREA)

Abstract

PURPOSE: To produce a discriminant regenerative signal having constant amplitude from a light receiving circuit in a simple configuration by automatically controlling the gain of the circuit for the AC component of its photodetector and automatically controlling the level of the circuit for the DC component thereof.
CONSTITUTION: When a light input level to a photodetector D1 becomes high, a DC amplifier AMP produces higher output, which is partially applied through a low pass filter to a resistor R2. Thus, the resistance of the resistor R2 becomes low, and the amplifier AMP thus produces a lower output. When the light input level to the photodetector D1, on the other hand, becomes low, the DC amplifier AMP produces lower output. Thus, the amplifier AMP automatically controls its gain with respect to the AC component of the input signal. However, the amplifier AMP does not control its gain with respect to the DC component of the input signal. However, a circuit network of a capacitor C3 and resistors R3∼R6 rectifies the mean value of the DC component of the input signal. A comparator COMP compares the mean rectified value with the output of the amplifier AMP to produce a discriminant regenerative signal. Therefore, the comparator COMP can produce the discriminant regenerative signal having cnstant amplitude.
COPYRIGHT: (C)1980,JPO&Japio
JP2009579A 1979-02-22 1979-02-22 Light receiving circuit Pending JPS55113383A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2009579A JPS55113383A (en) 1979-02-22 1979-02-22 Light receiving circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2009579A JPS55113383A (en) 1979-02-22 1979-02-22 Light receiving circuit

Publications (1)

Publication Number Publication Date
JPS55113383A true JPS55113383A (en) 1980-09-01

Family

ID=12017545

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2009579A Pending JPS55113383A (en) 1979-02-22 1979-02-22 Light receiving circuit

Country Status (1)

Country Link
JP (1) JPS55113383A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59226527A (en) * 1983-06-08 1984-12-19 Oki Electric Ind Co Ltd Circuit for suppressing dc variation
JPS61212933A (en) * 1985-03-14 1986-09-20 ブル・ソシエテ・アノニム Electrooptic transducer

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59226527A (en) * 1983-06-08 1984-12-19 Oki Electric Ind Co Ltd Circuit for suppressing dc variation
JPH0532934B2 (en) * 1983-06-08 1993-05-18 Oki Electric Ind Co Ltd
JPS61212933A (en) * 1985-03-14 1986-09-20 ブル・ソシエテ・アノニム Electrooptic transducer

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