Current Ratings of Electronic Devices for Intermittent Service

Electronic devices are used extensively for switching, relaying, welding, and similar service resulting in intermittent loads. In the paper methods for assigning standard ratings suitable for such intermittent loads are investigated, both for singleanode tubes and tube circuit combinations. Vapor-filled tubes with oxide-coated filaments are treated somewhat in detail in order to develop the basic considerations. Other types of tubes, such as the pool-type and cold-cathode, are only briefly discussed. A method of rating which seems generally applicable is proposed, with the suggestion that its suitability for the great variety of conditions encountered be further investigated.