GB501716A - A ward-leonard control system especially applicable to electric motors for driving, elevating and/or traversing gear of gun turrets - Google Patents

Abstract

501,716. Control of D.C. motors. RHEINMETALL - BORSIG AKT. - GES., and GIETMANN, A. July 25, 1938, No. 22020. [Class 38 (iii)] Varying E.M.F.-A system of the Ward- Leonard type, applicable especially to motors effecting adjusting movements of guns, in which the generator is excited by a control exciter operated manually at varying speeds, comprises means varying the field of the control exciter so that the relationship between the exciter voltage and speed is non-linear, and increments of voltage produced by equal increases of speed become greater as the speed increases. The exciter A, Fig. 1, has a field winding a1 of constant energization, and a field a2 energized in accordance with exciter speed from an auxiliary exciter B driven with the exciter A, and having a constant field b. The field b of the exciter B may be energized from a second auxiliary exciter driven with the exciter A and having a constant field. Shunt or series fields may be provided on the exciters to compensate for the resistance voltage drop. In a modification the field al of the exciter A is constantly energized and the field a2 energized by the exciter voltage. In a further modification, Fig. 4, the exciter field a2 is supplied from the exciter B which is driven with the exciter A and has two field windings. One winding bl is constantly energized, and the other b2 is energized from the exciter A. The fields produced by the windings b1, b2 are in opposition and at low speeds the field a2 weakens the field al, while at higher speeds the field a2, reverses and assists the field a1. The relationship between exciter voltage and speed for each of the arrangements described, is explained in the Specification with reference to Figs. 1a, 2a, 3a and 4a (not shown).