GB855468A - Improvements in or relating to electric impulse counters - Google Patents

Abstract

855,468. Counting apparatus. RINGSDORFF-WERKE G.m.b.H. March 31, 1959 [March 27, 1958; Feb. 4, 1959], Nos. 10919/59. Class 106 (1). [Also in Group XXXV] In an electrical impulse counter a multitoothed ferromagnetic rotor 3, connected to a counter mechanism, rotates between the poles of stator cores 1, 2 which have phase-splitting windings 4, 7 connected across input terminals 11 so that on receipt of an impulse, rotor 3 is attracted first to core 1 then to core 2, the complete movement completing one step of the counter. The radial spacing of the pole ends equals that of the extremities of the rotor and the cores are so placed that when the teeth of rotor 3 are opposite the poles of one, the poles of the other face the spaces between the teeth. Winding 4 is in series with capacitor 5, resistance 6 and winding 7 in series with inductor 8 and resistor 9. Core 1, on receipt of a pulse, is energized and the current fluctuates according to graph a (Fig. 2), whilst that in core 2 increases as on e-function (graph b). At a time t 1 when b is small rotor 3 is atrracted by core 1 to make a half-step and at time t 2 when a is zero core 2 attracts the rotor to complete the counting step. As both movements impart acceleration to rotor 3, an eddy current brake 12 (wound of high-conductivity metal) is provided on core 2 to halt the rotor. The brake operates only when core 2 is energized and as it delays the generation of flux in core 2 it can replace inductor 8. At time t 1 the small flux in core 2 which slightly impedes rotor movement may be avoided by passing the current in coil 4 through a compensating coil on the core (Fig. 3, not shown), to produce a field equal and opposite to that produced by coil 7 at time t 1 . At time t 2 the compensating coil has zero current (Fig. 4, not shown).