GB862025A - Improvements in or relating to subscribers' telephone sets - Google Patents

Improvements in or relating to subscribers' telephone sets

Info

Publication number
GB862025A
GB862025A GB3995857A GB3995857A GB862025A GB 862025 A GB862025 A GB 862025A GB 3995857 A GB3995857 A GB 3995857A GB 3995857 A GB3995857 A GB 3995857A GB 862025 A GB862025 A GB 862025A
Authority
GB
United Kingdom
Prior art keywords
line
circuit
dec
arms
loss paths
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.)
Expired
Application number
GB3995857A
Inventor
Frederick Arthur Wilson
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.)
Post Office
Original Assignee
Post Office
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 Post Office filed Critical Post Office
Priority to GB3995857A priority Critical patent/GB862025A/en
Publication of GB862025A publication Critical patent/GB862025A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/738—Interface circuits for coupling substations to external telephone lines
    • H04M1/76—Compensating for differences in line impedance

Abstract

862,025. Sub-station circuits. POSTMASTER GENERAL. Dec. 17, 1958 [Dec. 23, 1957], No. 39958/57. Class 40 (4). In a subscriber's sub-station two shunt-loss paths are provided, the first (that including R3) being connected across the transmitter and the second (that including R2) being connected across a winding 2A of the induction coil. The impedance of the loss paths varies inversely as the line current flowing in resistor R1 so that the sensitivity of the transmitter circuit is automatically varied in accordance with the resistance of the line. As shown the two loss paths form a balanced bridge circuit including pairs of similar rectifier elements arranged for push-pull working, the respective rectifiers of each pair forming two arms of the bridge circuit while the other two arms are formed by a centretapped non-linear resistor R1 connected in the line circuit for developing a voltage dependant upon the line current, which voltage biases the rectifiers in the conducting direction.
GB3995857A 1957-12-23 1957-12-23 Improvements in or relating to subscribers' telephone sets Expired GB862025A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3995857A GB862025A (en) 1957-12-23 1957-12-23 Improvements in or relating to subscribers' telephone sets

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3995857A GB862025A (en) 1957-12-23 1957-12-23 Improvements in or relating to subscribers' telephone sets

Publications (1)

Publication Number Publication Date
GB862025A true GB862025A (en) 1961-03-01

Family

ID=10412421

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3995857A Expired GB862025A (en) 1957-12-23 1957-12-23 Improvements in or relating to subscribers' telephone sets

Country Status (1)

Country Link
GB (1) GB862025A (en)

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