Improvements in or relating to telephone subscribers' instruments

778,756. Substation anti-side-tone circuits. STANDARD TELEPHONES & CABLES, Ltd. Jan. 4, 1956, No. 296/56. Addition to 775,564 Class 40 (4). The circuit of the parent Specification is modified by the replacement of inductor L and capacitor C3 by resistors R10 and R11 respectively. An additional r...

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Bibliographic Details
Main Author LEMAN HUGH SPENCE
Format Patent
LanguageEnglish
Published 10.07.1957
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
TELEPHONIC COMMUNICATION
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Summary:778,756. Substation anti-side-tone circuits. STANDARD TELEPHONES & CABLES, Ltd. Jan. 4, 1956, No. 296/56. Addition to 775,564 Class 40 (4). The circuit of the parent Specification is modified by the replacement of inductor L and capacitor C3 by resistors R10 and R11 respectively. An additional resistor R12 in the emitter circuit gives a negative feedback effect, and a line-holding resistor R13 is connected across the line terminals. A rectifier bridge W1 maintains the correct polarity of the D.C. supply to the transistor TR. Specification 694,021 also is referred to.
Bibliography:Application Number: GB19560000296