Switching and control

The paper outlines the reasons behind the decision to design a new compressed-air-operated mechanical switch for the Zeta circuit. The principal functions of the switch are given, and those factors which most affected the design are considered in more detail. Several hundred thousand discharges were initiated by the switch before its place, in the original Zeta circuit, was taken by ignitrons. Although Zeta is only an experimental apparatus, the scale and complexity of the equipment made a very comprehensive system of controls necessary. Interlocks and automatic sequence controls were provided, partly to prevent damage to personnel and equipment and partly to permit the speedy location of faulty apparatus. The necessity for carrying out test sequences of up to 3500 discharges at 12sec intervals has more than justified the decision to give special attention, from the earliest days, to the switching and control of the Zeta circuit.