GB346319A - Improvements in and relating to supply circuits for radio receivers and the like - Google Patents

Abstract

346,319. Valve circuits. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Cornell, J. I. ; 401, Michigan Avenue, Schenectady, New York, U.S.A.) Oct. 4, 1929, No. 30162. Convention date, Oct. 4, 1928. Void [Published under Sect. 91 of the Acts]. [Class 40 (v).] Anode and grid bias voltages for the valves of a receiver are supplied from tappings on a resistance, across the supply terminals, the anode and grid bias connections for one of the valves being spaced across a part of the resistance while the corresponding connections for another valve are spaced across a separate part of the resistance. Valve 14 is a single high-frequency amplifier which may have a varying load, the anode, cathode return and grid bias connections being made at 29, 30, 31 on resistor 12 ; the amplification may be varied by moving the grid bias tap. The detector valve 15 has its anode, cathode return and grid bias connections at 7, 38, 29 on the resistor, thus utilizing the voltage drop across a separate portion from that of valve 14, the tapping 29 being common to the grid of valve 15 and anode of valve 14. Valve 13 represents one of a number of output stages, its anode and cathode leads being connected directly across the supply terminals 7, 8 ; grid bias is obtained from the resistor 20, the filament being heated by alternating current. The anode and cathode tapping points of all the valves are respectively shunted by condensers 40, 41. The arrangement ensures constant relation between grid bias and anode potential for the detector 15 irrespective of varying load taken by valve 14.