Some Factors Affecting Design, Construction, And Testing of High Reliability Relays

This paper describes some improvements in design, manufacturing, and testing of 2-pole and 4-pole 5-ampere high reliability relays of low profile and small volume. Design features contributing to long life and high reliability at full load or dry-circuit load include elimination of contact buttons, push-pull actuation rather than spring bias of common contacts, gold plating as a lubricant for armature pivots, peeling rather than sliding contact action to prevent sticking, improved methods of outgassing and sealing, and other features. Reasons are given to justify several unusual design features, including the orientation of contact blades with respect to the header and the use of coil cores working magnetically in parallel. Improved miss-testing equipment includes testing at both polarities, detection of make-before-break errors, and emphasizes suppression of inductive transients.