Abstract: A driving circuit includes a relay driver for selectively connecting a relay coil with (a) a first current path between the relay driver and a relay voltage input or (b) a second current path between the relay driver and a ground connection. Another relay driver selectively connects the coil with (a) a third current path between the other relay driver and the relay voltage input or (b) a fourth current path between the other relay driver and the ground connection. The relay drivers may connect the coil between the second and third current paths for latching the relay, and between the first and fourth current paths for unlatching the relay. The driving circuit applies signals of opposite polarity and different magnitudes through the coil to latch and unlatch the relay. The signal for unlatching can be of lower voltage than the signal for latching the relay.
Type:
Grant
Filed:
April 22, 2015
Date of Patent:
September 5, 2017
Assignee:
Emerson Electric Co.
Inventors:
John F. Broker, Xiaobing Zhu, Cuikun Chu
Abstract: This invention relates to the field of very high current integrated power systems and defines a system where an alternating current inductive generator (13), controlled by a generator voltage regulator (14), is coupled to alternating current inductive load (11), controlled by an alternating current inductive load controller (12), all controlled by a supervisory control and data acquisition system (17) with externally adjustable power rate constraints (21) that define a new anticipatory mode integrated power system (10).
Type:
Grant
Filed:
March 10, 2011
Date of Patent:
May 5, 2015
Assignee:
Northrop Grumman Systems Corporation
Inventors:
Thomas D. Roettger, Mohamed Belkhayat, Craig J. Nordby, Joseph M. Maurio, William Patalon
Abstract: A method and system that provides for simultaneous or independent start-up of two or more three-phase AC motors with reduced starting current. Two AC motors have their stator windings connected in series across the power network. If more than two AC motors are to be started, the stator windings of the additional motors are connected in parallel with the stator windings of one or both of the first two motors and the phase leads of the additional motors are connected to the power network. The voltage result vector is less than the sum of the rated voltage of each motor. After a preset time delay or when the motors reach a certain speed, the rated voltage is applied to each motor by disconnecting the stator windings from the series connection and connecting the stator windings of each motor in a delta configuration.