GB845204A - Magnetic amplifier circuit - Google Patents

Abstract

845,204. Circuits employing non-linear magnetic elements. SPERRY RAND CORPORATION. March 4, 1957, No. 7042/57. Class 40 (9). A first winding on a magnetic core having a substantially rectangular hysteresis loop is pulsed successively during spaced intervals between which the core is set to saturation in one direction or the other by means of one or more other windings on the core so that the successively-applied pulses are selectively caused to encounter a high or a low impedance in the first winding. In Fig. 2 the winding 21 is energized by the power pulses shown in Fig. 3, rectifier D1 gating the positive half-cycles. A control-winding 22 has each end clamped to earth by sources of potential - V and rectifiers D5 and D6. Clock pulses occurring during the negative half-cycles of the power pulses are applied to one end of the control winding 22 over an inhibition gate 27 which suppresses a clock-pulse whenever an input pulse is applied to the other end of the control winding. In the absence of an input pulse the clock-pulse holds the core saturated in a direction such that the succeeding power pulse meets a high impedance and what current passes through the coil 21 is suppressed by the equal and opposite current from a source - V through a diode D2 tied to the output lead 24. When an input pulse is received the core is switched to saturation in the opposite direction such that the succeeding power pulse meets a low impedance in winding 21 and a substantial output appears on lead D. The voltage induced in winding 21 when the core is switched by the input pulse is backed off by the negative portion of the power pulse waveform. In the above arrangement an output is produced subsequent to an input. If the sense of winding 22 is reversed an output is produced for each power pulse except those preceded by an input pulse. In Fig. 4 an alternative arrangement comprises a winding 41 energized at A by the power pulses shown in Fig. 5. To a terminal D of an input winding 42 a negative bias is normally applied to hold the core saturated so that winding 41 does not switch the core when energized by a positive power pulse. The negative bias is switched to positive to constitute an input signal which over rectifier D9 energizes a winding 43 to switch the core so that the subsequent positive power pulse switches the core back again and in so doing induces an output voltage in a winding 44 which over rectifier D10 energizes a load RL. When the core is switched by the input pulse the negative excursion of the power pulse waveform decouples the winding 41 while blocking pulses applied to terminal C decouple the output winding 44.