The present disclosure relates generally to electrical contactors, and particularly to controlling the closing action thereof.
Contactors for motor, lighting, and general purpose applications are generally designed with one or more power contacts that change state by energizing and de-energizing an excitation coil. Contactors may be configured with a single pole or with a plurality of poles, and may include both normally open and normally closed contacts. In a contactor employing normally open contacts, energization of the coil results in closure of the contacts. The nature of a contactor application tends to result in tens of thousands or even millions of close and open operations over the life of the contactor. As such, attention is paid to the mechanical attributes of the contactor that enables such duty of operation. In the event that the contactor closes and opens onto an energized electrical circuit, not only do the contacts experience a mechanical duty, but they also experience an electrical duty, which manifests itself in the formation of an electrical arc. During the closing of a normally open contactor, the dynamics of the closing action tends to result in contact bounce at the point of closure, which under a load condition may result in multiple electrical arcs being drawn and extinguished, which in turn tends to increase the degree of wear at the contacts and reduce the life expectancy of the contacts. While present contactors may be suitable for their intended purpose, there remains a need in the art for an electrical contactor that provides for reduced contact wear and increased contactor life.
USPTO Backgrounds
USPTO Backgrounds