GB734013A - Electrical pulse counting circuits - Google Patents

Abstract

734,013. Counting-apparatus. NATIONAL RESEARCH DEVELOPMENT CORPORATION. April 23, 1953 [April 23, 1952], No. 10263/52. Class 106 (1). In an electromagnetic-relay counting circuit, one particular relay only changes state at each of one set of alternate half-cycles of the drive contacts, and one of the other relays changes state at each one of the other set of alternate half-cycles. The sequence repeats only after at least four cycles. An arrangement, Figs. 1 and 1a, for counting, in a radix of sixteen, complete cycles of changeover contacts D, uses five sidestable polarized relays, each having two opposed coils. Tn a modification, Fig. 2, single-coil sidestable polarized relays are connected to voltages of opposite polarity, a change of state of a relay being effected by energizing its coil in the reverse sense to the last energization. A further arrangement, Fig. 6, employs simple two-winding relays. Make-before-break driving contacts D whilst operated maintain a holding circuit B<SP>1</SP> for relays 2-5 and whilst unoperated maintain a'holding circuit A<SP>1</SP> for relay 1. To avoid misoperation, the contacts D may be replaced by two pairs of changeover contacts D1, D2, Fig. 6a, operated in sequence. The circuit may be modified, Figs. 7 and 8'(not shown), for counting in a radix of ten. A radix-of-four counter, Fig. 5, employs simple single-coil relays each of which, on operation, completes a holding circuit for itself. Release is effected by short-circuiting the coil.