GB471499A - Improvements in or relating to electric transformers - Google Patents

Abstract

471,499. Converting; changing wave form. BRITISH THOMSON - HOUSTON CO., Ltd. Dec. 2, 1935, No. 33371. Void. Convention date, Dec. 1, 1934. [Class 38 (ii)] Relates to an arrangement for producing peaky potentials, particularly for the grid control of discharge devices, and consists in mounting the primary winding on an unsaturated part of the core, and the secondary winding on a yoke operating at saturation. A three limb core, Fig. 5, may be used, with the primary windings U1 on the outer limbs and the secondary windings U2, to give voltages 180‹ phase displaced, distributed over the two parts of the yoke. In a modification of this, two three limb cores, with a common yoke is used. By varying the magnitude of the primary voltage the breadth of the peak and thus the moment of ignition is varied. The Specification states that in a rectifier this may be used to give a constant output voltage with a varying input voltage. The small sinusoid component of the peaky voltage may be eliminated by injecting a sinusoidal component 180‹ phase displaced. This may be obtained from a tertiary winding mounted on the unsaturated part of the core. Phase shift to vary the moment of ignition may be obtained by connecting a variable resistance in the primary supply. Fig. 13 shows the construction of a transformer having windings arranged as in Fig. 5. A three-limbed core 1, operating unsaturated, carries the primary windings 3, 4, the secondary windings 5, 6 being mounted on a highly saturated yoke 2.