Cold-Cathode Gas-Filled Tubes as Circuit Elements

Three types of gas-filled control tubes are now in common use. The properties of cold-cathode tubes, the most recent of these to receive extensive application, have been considered and comparisons drawn with those of the more familiar thyratron and ignitron. It is concluded that in its own field of low-current control devices the cold-cathode tube has several inherent advantages which will ensure a wide use for it in the future. These advantages are, the ability to operate without cathode heating power, the ability to start immediately when a signal is applied, and the absence of deterioration in standby service. A number of typical circuits illustrating the capabilities of the tubes as circuit elements have been described. Several of these are in commercial applications. One, involving some hundreds of thousands of tubes, has been operating for several years and proves beyond doubt that the cold-cathode tube is a valuable addition to the array of control devices available to the circuit engineer.