Construction of cold-cathode counting or stepping tubes

ELECTRONIC digital counters have satisfactorily solved the problem of counting at speeds which are too great for mechanical or electromagnetic counters. These high-speed counters usually employ chains of trigger devices such as hot-cathode multivibrators¹ or cold-cathode glow discharge tubes.² Coupling between elements in the chain is arranged so that the triggering of one element prepares or primes the next succeeding element. This article describes a new principle of construction which permits coupling from one cold cathode to the next within a single common tube envelope, thereby considerably simplifying the counting tube and circuit. Only one load resistor and three tube-connection terminals are required, regardless of the number of counting stages, although additional elements are usually required in order to obtain information by other than visual means.³