GB844089A - Magnetic current-control devices - Google Patents

Abstract

844,089. Magnetic amplifiers. FOXBORO CO. March 7, 1958 [April 4, 1957], No. 7442/58. Class 40 (9). In an auto-self-excited full-wave rectifying transductor having its power windings on separate cores, a short-circuit path is inductively coupled to both cores and is constituted either by a single-short-circuited winding 52, 88, Fig. 1, or by paralleled control windings such as 126, 128, Fig. 3, each on a separate core. In the Fig. 1 embodiment, auto-self-excited full-wave rectifying transductors 10, 12 are connected in cascade and provide an output across a resistor 70 in response to control signals in a winding 46, both transductors being energized from centre-tapped secondary windings 28, 66 of a power transformer 30. Feedback windings 78, 80 on the first transductor stage 10 are energized by the output from transductor 12, while the latter stage has a transient feedback circuit comprising winding 86 and condenser and resistor 82, 84. A smoothing condenser 76 is included in the output circuit, and the first transductor stage 10 includes a bias winding which is energized from a rectifying circuit 50. A pull-pull circuit controllable by alternating signals applied to terminals 134, 136 is shown in Fig. 3. Auto-self-excited full-wave rectifying transductors 90, 92 energized from a centretapped transformer 110 are also used in this embodiment, but the short-circuit path is provided on each transductor by connecting the control windings such as 126, 128 in parallel. The push-pull output is developed across resistors 120, 122 and appears at terminals 146, 148, and a feedback circuit is provided comprising windings 150, 152 and a current-limiting resistor 154. Both transductors include bias windings 138, 140 which are adjustably energized from a rectifying circuit 142.