GB906596A - Improvements in index carriers and apparatus for electrically reading index carriers - Google Patents

Abstract

906,596. Sensing record cards. APPEL, L. April 16, 1959 [April 17, 1958], No. 13052/59. Class 106 (1). Data sensing apparatus comprises at least one pair of electrodes between which is guided a flat, flexible index carrier comprising a layer of high-tension-resisting insulating material, the electrodes being connectible to a voltage supply source, whereby the presence of a perforation in the index carrier allows a corresponding current impulse to flow by the formation of an electric arc through the perforation, the impulse being amplified by an electronic amplifier before being utilized. As described, a card 1 formed from two sheets of paper with an insulation layer 2 bonded between them, contains a minute perforation 4 which, when located between electrodes 3 which are subject to a high-tension alterna ting voltage from a transformer U 2 , allows current to flow through an arc between the electrodes and, by developing a P.D. across a resistor R 2 , fires a thyratron Th and so energizes a relay I 2 controlling a utilization circuit. Where combination coding is used the relay contacts are interconnected (Fig. 2, not shown) for de-coding purposes. Further electronic means may be used instead of the relay I 2 , and another way of controlling the firing of the thyratron is mentioned. The card may include a layer of conductive or semi-conductive material to act as a counter-electrode. Apart from cards, plates, strips, films or bands may be used.