GB775142A - Improvements in or relating to electric circuits incorporating magnetic amplifiers - Google Patents

Abstract

775,142. Magnetic amplifiers. GENERAL ELECTRIC CO., Ltd., and WRIGHT, R. E. Jan. 18, 1956 [Jan. 25, 1955], No. 2229/55. Class 40 (4). A pair of "high speed" or " resetting" magnetic amplifiers 1, 2 of the type in which alternating sources 10, 13, 17, 19 cyclically apply demagnetizing and magnetizing currents over rectifiers 9, 16, 18 to control and output windings 4, 7 and 3, 6 respectively during different time periods, are connected in cascade in association with P-N-P junction transistors 11, 14 which directly control the demagnetizing currents over the base and collector electrodes in accordance with the emitter-base current. As shown, positive control signals are applied to terminal 12 and a directly proportional and amplified output is obtained at terminals 20 after a delay time of one and a half cycles of alternating voltage. A resistor 15 is included in the output circuit of amplifier 1 to limit the current through winding 3 and the transistor 14 when the core 5 becomes saturated. It is stated that the four alternating sources, which are the same as to frequency, phase and amplitude, may be taken from separate secondary windings on a single transformer, and that the emitter-base connections of the transistors may be reversed. The arrangement is also stated to be applicable to high-speed magnetic amplifiers of the fullwave type.