GB141816A - Improvements in or relating to electric-motor control-systems - Google Patents

Abstract

141,816. Zweigbergk, T. Jan. 22, 1919. Master control systems.- In a master control system with resistance contactors operated by an auxiliary electric motor, a separate contactor controls the main circuit, and the auxiliary motor is reversed by a switch operatively connected with the controller. The motor A rotates a cam shaft for the operation of levers to close the contactors controlling the resistance sections Q in series with the main motor R, and is connected to the brushes W which wipe over reversing-contacts M - - M<4> on the arm N of the contactor which operates the contact J<2> in the main circuit. When the controller U is moved to its closed position, the solenoid L is energized to raise the contact J<2> and so start the motor R. The reversing-contacts M - - M<4> are operated at the same time, and the auxiliary motor runs in the direction to cut out resistance. If the current in the motor R is excessive, the relay G closes the contacts X, Y and short-circuits the armature of the motor A, thereby stopping the cutting-out of the resistance Q. When the controller U is moved to the stop position, the contact J<2> drops and opens the main circuit. The contacts M - - M<4> also drop and reverse the field S of the motor A; this motor then runs to insert the resistance Q. The auxiliary motor is always in circuit when the line is energized, and its movement is limited by stops.