GB1522903A

GB1522903A – Optically coupled apparatus
– Google Patents

GB1522903A – Optically coupled apparatus
– Google Patents
Optically coupled apparatus

Info

Publication number
GB1522903A

GB1522903A
GB447576A
GB447576A
GB1522903A
GB 1522903 A
GB1522903 A
GB 1522903A
GB 447576 A
GB447576 A
GB 447576A
GB 447576 A
GB447576 A
GB 447576A
GB 1522903 A
GB1522903 A
GB 1522903A
Authority
GB
United Kingdom
Prior art keywords
input
amplifier
impedance
output
signal
Prior art date
1975-02-10
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.)

Expired

Application number
GB447576A
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.)

AT&T Corp

Original Assignee
Western Electric Co Inc
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.)
1975-02-10
Filing date
1976-02-04
Publication date
1978-08-31

1976-02-04
Application filed by Western Electric Co Inc
filed
Critical
Western Electric Co Inc

1978-08-31
Publication of GB1522903A
publication
Critical
patent/GB1522903A/en

Status
Expired
legal-status
Critical
Current

Links

Espacenet

Global Dossier

Discuss

Classifications

H—ELECTRICITY

H04—ELECTRIC COMMUNICATION TECHNIQUE

H04B—TRANSMISSION

H04B3/00—Line transmission systems

H04B3/02—Details

H04B3/44—Arrangements for feeding power to a repeater along the transmission line

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

H—ELECTRICITY

H04—ELECTRIC COMMUNICATION TECHNIQUE

H04B—TRANSMISSION

H04B3/00—Line transmission systems

H04B3/02—Details

H04B3/36—Repeater circuits

Abstract

1522903 Transistor amplifiers WESTERN ELECTRIC CO Inc 4 Feb 1976 [10 Feb 1975] 04475/76 Heading H3T Two optically coupled circuits, e.g. for a bilateral communication system, each comprises an amplifier, e.g. 62, having a light-emissive device 78 coupled to its output, and light detectors 64, 80 disposed to receive said light, one 80 being coupled in an output circuit and the other 64 providing negative feedback to the amplifier 62, whereby non-linearity between an input signal to the amplifier and the corresponding signal from the output circuit is reduced, the apparatus further including an input/output terminal 56 coupled to an input of amplifier 62 via summing impedance R50, the output 66 of the other circuit being coupled to an input of 62 via a cancelling impedance Z2′, for cancelling signals from 66 at amplifier 62. The output amplifiers are 84, 68, the input amplifier corresponding to 62 for the opposite direction being 92. An input signal from a first telephone set (not illustrated) connected at T, R is fed via input terminal 56 to the output of 68 and to an input 60 of 62, in parallel, the impedance Z11 being a terminating impedance for the input line. The output terminal 66 of amplifier 68 is a virtual earth, and hence the input signal cannot reach the other input 70 of amplifier 62. After passing through the optical coupling 78, 80 and amplifier 84 the signal emerges at a second telephone set connected to Tl, Rl. An impedance Z3′ (corresponding to Z21) acts as a hybrid cancellation impedance to ensure that the signal components reaching the differential inputs of amplifier 92 are equal, so that no reflected signal is produced. Networks Zol’, Zo2′ are gain control feedback impedances switchable by S1, S2 respectively to provide alternative values of gain in amplifiers 68, 84. R64, C16 and R65, C17 serve for determining the gain and shaping the frequency response of amplifiers 62, 92. Capacitors C28 and C29 compensate for the stray capacitances CS1, CS2 in parallel with the optical couplings, so as to prevent common mode signals from propagating through the system. Resistors R53, R79 in Zol’, Zo2′ respectively may be varied in value to compensate for mispositioning of the light sources with respect to the light detectors. The light sources may be gallium phosphide LED’s and the detectors silicon diodes operating in the reverse biased mode. The system may be used as an optical transmission system by optical fibre couplings. The input and power circuitry 57 comprises a polarity guard (102), Fig. 5 (not shown), consisting of a diode bridge, and a high impedance constant current sink which provides the supply voltages � Vx and Vx ref. A Zener diode (Dzl) protects two transistors (Q3, Q4) against excessive supply voltage. The input and power circuitry 59 comprises a chopper (S3) driven by an oscillator to produce A.C. from a D.C. supply, Fig. 6 (not shown), to provide the supply voltages �Vy and Vy ref, the circuit including three thermistors (Th1-3).

GB447576A
1975-02-10
1976-02-04
Optically coupled apparatus

Expired

GB1522903A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

US54840475A

1975-02-10
1975-02-10

Publications (1)

Publication Number
Publication Date

GB1522903A
true

GB1522903A
(en)

1978-08-31

Family
ID=24188718
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB447576A
Expired

GB1522903A
(en)

1975-02-10
1976-02-04
Optically coupled apparatus

Country Status (5)

Country
Link

JP
(1)

JPS51105701A
(en)

CA
(1)

CA1062824A
(en)

DE
(1)

DE2604805A1
(en)

GB
(1)

GB1522903A
(en)

NL
(1)

NL7601288A
(en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

DE3308987C2
(en)

*

1983-03-14
1990-10-04
Siemens Ag, 1000 Berlin Und 8000 Muenchen, De

DE3325420C2
(en)

*

1983-07-14
1989-08-10
Telefunken Electronic Gmbh, 7100 Heilbronn, De

1976

1976-01-29
CA
CA244,517A
patent/CA1062824A/en
not_active
Expired

1976-02-04
GB
GB447576A
patent/GB1522903A/en
not_active
Expired

1976-02-07
DE
DE19762604805
patent/DE2604805A1/en
not_active
Withdrawn

1976-02-09
NL
NL7601288A
patent/NL7601288A/en
not_active
Application Discontinuation

1976-02-10
JP
JP51012922A
patent/JPS51105701A/ja
active
Pending

Also Published As

Publication number
Publication date

JPS51105701A
(en)

1976-09-18

DE2604805A1
(en)

1976-08-19

NL7601288A
(en)

1976-08-12

CA1062824A
(en)

1979-09-18

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Legal Events

Date
Code
Title
Description

1978-12-20
PS
Patent sealed

1984-10-17
PCNP
Patent ceased through non-payment of renewal fee

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