Improvements in or relating to electrical circuits employing static electrical switches

663,574. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd. March 4. 1949, No. 5933/49. Class 40 (iv). [Also in Groups XL (b) and XL (c)] Impulse storage and regenerator equipment employs a chain of discharge tubes (see Group XL (c)) upon which the digits comprising a number are stored as a pattern formed of conducting tubes spaced apart by non-conducting tubes in accordance with the value of each digit. Stepping pulses applied in common to the cathodes of all the tubes cause the complete pattern to travel stage-bystage along the chain influencing the final tube to control the regeneration of impulses in accordance with the stored number. In Fig. 5 a five-digit number impulse train received on relay A is stored on a chain of 50 tubes G1-G50, the chain subsequently serving to control the regeneration of the impulses by magnet-springs L1 operating at controlled speed and make-and-break ratio. Tubes GA-GE function as a digit-counting chain. Relay A operates via the line loop and operates relay B over a1 up which prepares C over b up. Contact b2 up triggers tubes G1 and GA, and then relay A follows the separate impulses and over a2 applies voltage pulses across R7 to the cathodes of tubes G1-G50 which step the fired tube along the chain, one stage for each impulse. Relay C is slowreleasing and operates to the first and releases after the last impulse of each digit train. On releasing, contact c1 back triggers G1 again, and contact c2 back moves the digit-counting chain along one, triggering GB and extinguishing GA. This process is repeated for the other digits of the number, thus building up a pattern of conducting tubes spaced apart by non-conducting tubes in accordance with the value of each digit. On c2 falling back after the fifth tube is received, tube GF is triggered, operating relay D. Over dl up the control of the storage chain is transferred from a2 to magnet springs M2, and d2 up prepares relay IG for operation at the next " break " of magnet springs M1. Contact d3 up transfers control of the digit-counting chain from relay C. to relay E. Contact d4 triggers tube GA, resetting the counter. On the first break of springs Ml following operation of relay D, relay IG operates. Contact ig2 connects resistance R7 to springs M2 and the pattern on the storage chain then moves along stage-by-stage until the final tube G50 triggers, operating relay E. Contact c1 up triggers tubes GK and GJ, operating relays G and F. Relay G has a delay such that con