JPS5471502A - Alarm circuit for photo reception - Google Patents

Alarm circuit for photo reception

Info

Publication number
JPS5471502A
JPS5471502A JP13784977A JP13784977A JPS5471502A JP S5471502 A JPS5471502 A JP S5471502A JP 13784977 A JP13784977 A JP 13784977A JP 13784977 A JP13784977 A JP 13784977A JP S5471502 A JPS5471502 A JP S5471502A
Authority
JP
Japan
Prior art keywords
circuit
output
signal
average value
photo
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.)
Granted
Application number
JP13784977A
Other languages
Japanese (ja)
Other versions
JPS5737261B2 (en
Inventor
Takashi Kihara
Satoshi Ikeuchi
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 JP13784977A priority Critical patent/JPS5471502A/en
Publication of JPS5471502A publication Critical patent/JPS5471502A/en
Publication of JPS5737261B2 publication Critical patent/JPS5737261B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/66—Non-coherent receivers, e.g. using direct detection
    • H04B10/69—Electrical arrangements in the receiver
    • H04B10/691—Arrangements for optimizing the photodetector in the receiver
    • H04B10/6911—Photodiode bias control, e.g. for compensating temperature variations

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Light Receiving Elements (AREA)
  • Dc Digital Transmission (AREA)
  • Optical Communication System (AREA)

Abstract

PURPOSE:To establish the circuit with small sized constitution which can detect the average value of the output of reception system, discriminate the presence of photo signal with the level difference of the average value level, produce alarm without photo signal, and can be usable for the reception system without using the timing signal. CONSTITUTION:The avalanche photo diode 1 receiving photo signal and converting it into an electric signal, amplifying circuit 2 amplifying the electric output converted and the peak detection circuit 3 detecting the peak value of the output of the amplifier 2 are provided. Further, the bias voltage control circuit 4 controlling the bias voltage of the diode 1 with the output of the circuit 3 and the slice circuit slicing the output of the amplifier 2 are provided and the output side of the circuit 5 is provided with the average value detection circuit 6 and the comparison circuit 7. In addition, the average value of the output of the reception system is detected with the circuit 7 and the interruption of photo signal is detected with lower average level than the comparision voltage Vs in specified level, producing the alarm signal.
JP13784977A 1977-11-18 1977-11-18 Alarm circuit for photo reception Granted JPS5471502A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13784977A JPS5471502A (en) 1977-11-18 1977-11-18 Alarm circuit for photo reception

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13784977A JPS5471502A (en) 1977-11-18 1977-11-18 Alarm circuit for photo reception

Publications (2)

Publication Number Publication Date
JPS5471502A true JPS5471502A (en) 1979-06-08
JPS5737261B2 JPS5737261B2 (en) 1982-08-09

Family

ID=15208230

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13784977A Granted JPS5471502A (en) 1977-11-18 1977-11-18 Alarm circuit for photo reception

Country Status (1)

Country Link
JP (1) JPS5471502A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5632859A (en) * 1979-08-27 1981-04-02 Fujitsu Ltd Pcm repeater
JPS56111358A (en) * 1980-02-06 1981-09-03 Matsushita Electric Ind Co Ltd Signal control circuit
JPS5769228A (en) * 1980-10-18 1982-04-27 Fuji Electric Co Ltd Deterioration detection system for optical transmitting circuit
JPS58159042A (en) * 1982-03-16 1983-09-21 Hitachi Cable Ltd Carrier detecting circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5093005A (en) * 1973-12-17 1975-07-24

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5093005A (en) * 1973-12-17 1975-07-24

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5632859A (en) * 1979-08-27 1981-04-02 Fujitsu Ltd Pcm repeater
JPS56111358A (en) * 1980-02-06 1981-09-03 Matsushita Electric Ind Co Ltd Signal control circuit
JPS5769228A (en) * 1980-10-18 1982-04-27 Fuji Electric Co Ltd Deterioration detection system for optical transmitting circuit
JPS58159042A (en) * 1982-03-16 1983-09-21 Hitachi Cable Ltd Carrier detecting circuit

Also Published As

Publication number Publication date
JPS5737261B2 (en) 1982-08-09

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