GB811413A - Telephone sub-station including transistors - Google Patents

Telephone sub-station including transistors

Info

Publication number
GB811413A
GB811413A GB18863/57A GB1886357A GB811413A GB 811413 A GB811413 A GB 811413A GB 18863/57 A GB18863/57 A GB 18863/57A GB 1886357 A GB1886357 A GB 1886357A GB 811413 A GB811413 A GB 811413A
Authority
GB
United Kingdom
Prior art keywords
bell
transistors
condenser
including transistors
june
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
GB18863/57A
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.)
Autophon AG
Original Assignee
Autophon AG
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 Autophon AG filed Critical Autophon AG
Publication of GB811413A publication Critical patent/GB811413A/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
    • H04M1/74—Interface circuits for coupling substations to external telephone lines with means for reducing interference; with means for reducing effects due to line faults

Abstract

811,413. Substation circuits. AUTOPHON A.G. June 14, 1957 [June 19, 1956], No. 18863/57. Class 40 (4). In a substation including transistors T1, T2 supplied over the line L, an A.C. bell G 1 in series with a condenser C1, and voltage dividers R2, R3 and R6, R7 for providing the bias for the control electrodes of the transistors, the supply for the voltage dividers and for those of the transistors which do not send their output signal over the line (T1, as shown) is derived from a point between the bell G1 and the condenser C1. The bell and condenser act as a low-pass filter to prevent feedback of the voice current, and the bell also forms, with a resistor R1, a voltage divider feeding the transistor amplifier T1, T2 which is used to amplify the output of the transmitter M. A second bell may be connected to terminals WK which are shortcircuited when cradle contacts GK are closed.
GB18863/57A 1956-06-19 1957-06-14 Telephone sub-station including transistors Expired GB811413A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH811413X 1956-06-19

Publications (1)

Publication Number Publication Date
GB811413A true GB811413A (en) 1959-04-02

Family

ID=4538522

Family Applications (1)

Application Number Title Priority Date Filing Date
GB18863/57A Expired GB811413A (en) 1956-06-19 1957-06-14 Telephone sub-station including transistors

Country Status (1)

Country Link
GB (1) GB811413A (en)

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