An electronic teleprinter distributor

Although most present-day teleprinters have mechanically operated cam-type distributors, which are quite satisfactory and reliable, a recent trend in the industry has been to develop electronic ones.1,2 This paper describes an electronic distributor developed at the electrical engineering laboratory of the University of Roorkee, India. The distributor uses a ring counter consisting of cold cathode trigger tubes. The timing pulses are derived from the 50-cycle main supply. The 1.5-unit stop pulse is insured by a novel method of reversing the phase of the sinusoidal supply driving the pulse generator during the stop period of each signal train. Since no hot cathode tube is used at any stage of the distributor, it does not require any warm-up time. The distributor can be fed either directly from the keyboard or from a perforated tape. It can also be made to work from a 5-or 6-unit code by means of a code-selector switch.