GB425950A - Improvements in or relating to electron discharge device amplifiers - Google Patents

Abstract

425,950. Valve amplifying circuits. TELEFUNKEN GES. FUR DRAHTLOSE TELEGRAPHIE, 12, Hallesches Ufer, Berlin. Aug. 29, 1934, No. 24916. Convention date, Aug. 31, 1933. [Class 40 (v)] In a circuit comprising two cascaded stages of push-pull Class B amplification, closed circuits without interposed coupling reactances are provided for the grid currents in the second stage said currents having the same direction in the closed circuits as the anode currents of the valves of the preceding stage. As shown the anode circuits of the valves 1, 2 of the first stage comprise coupled chokes 13, 14 respectively and a common H.T. source 9. The anodes of valves 1, 2 are connected directly to the cathodes of the following pair of valves 3, 4 respectively, the grids thereof being connected through a common source 12 of grid bias to the junction of chokes 13, 14. The anodes of valves 3, 4 feed, through a common H.T. source 10, the two phase-opposed halves of the primary of an output transformer. A third stage may be added, in which case the cathodes of valves 3, 4 are connected to the grids of the following valves and the common anodes of the valves 3, 4 to the common cathodes of the following valves.