A survey of cold cathode discharge tubes

From the first neon discharge tubes of 1910, a range of devices has evolved covering a remarkable diversity of applications. Voltage regulators and reference tubes are available for voltages from 55 V-27 kV and currents from 1 ¿A-100 mA. Relay tubes offer current gains between 106 and 1012 and provide continuous control of loads of up to 2 kW or switch peak loads of 10 MW. The stepping tube has been developed to provide highly reliable counting at frequencies up to 1 Mc/s. Electronic flash tubes provide high-intensity light flashes of 1 ¿s-1 ms duration with colour closely approximating daylight. A diversity of gasfilled indicators and register devices provides on-off and in-line digital display of high reliability and long life. An outline of the historical development of cold cathode tubes is followed by a discussion of the leading characteristics of each class of tube currently available.