ELECTROMAGNETIC CONTACTOR WITH CONTROL CIRCUIT FOR PROVIDING ACCELERATION, COAST AND GRAB FUNCTIONS

摘要

ABSTRACT OF THE DISCLOSUREAn electromagnetic contactor or controller istaught in which the voltage which is impressed across theelectromagnetic armature accelerating coil is compared by amicroprocess against a menu of memory stored voltages withrelated delay angles. The delay angles are utilized toalter the conduction interval of a triac or similar gateddevice which is connected in series circuit relationshipwith the coil in question. During an ACCELERATION intervala number of consecutive full-wave rectified half-cycles ofvoltage pulses are phase angle or delay angle controlled sothat the amount of energy provided to the moving armatureof the contactor is approximately sufficient to cause thearmature to abut a fixed magnetic member. Furthermore,there is provided a separate memory menu for mid-flightadjustment of the armature to compensate for unknownvariations to fine tune the closing operation. This lattercorrection is known as COAST. There is also provided aGRAB function which supplies limited, relatively low levelcurrent to the armature at or near the time of abutment forpreventing "bounce". Mechanically interconnected with thearmature is a set of contacts which are caused to closeupon an external circuit for providing a useful function inresponse to the movement of the armature.