Improvements in or relating to television and like apparatus

Abstract

Abstract 412,126. Valve amplifying circuits. FERNSEH AKT.-GES., Goerzallee, Zehlendorf, Berlin. Dec. 21, 1933, No. 36044. Convention date, Dec. 23, 1932. [Class 40 (v).] The modulation range of a television transmitter is constant whatever the contrast or mean brightness in the object. Two valves 10, 11, auxiliary to the amplifying-valves 2 .. 5, are biassed to the peak valves of the photoelectric currents above and below the mean value respectively, by charging condensers 14, 15, shunted by resistances 16, 17, from the signal currents through rectifiers 12, 13, for example thermionic valves. The anode currents of the valves 10, 11 pass respectively through resistances 7, 8 in series in the grid circuit of the amplifying-valve 4 of variable-mu type. Alternatively the anode potential of the amplifying-valve is varied.

Inventors

No inventors recorded.

Bibliographic Details