GB152490A - Improvements in or relating to electric-motor control-systems - Google Patents

Abstract

152,490. Zweigbergk, T. Sept. 11, 1919, Master control systems. -In a control system of the type described in Specification 141,816, the master controller and extensions on each motor controller have series of contacts connected by relays which are arranged to short-circuit the auxiliary motor of the motor controller when it successively reaches the various positions corresponding with the positions of the master controller. The windings M<1> - - M<4> of the relays are connected between the contacts a' - - a<4> of the master controller A and the contacts l<1> - - l<4> of the motor controller extension L. The solenoid B<5> operates the main contactor B<2> and also a reversing-switch J for the auxiliary motor. When the master controller is moved to the first notch, the contactor B<2> closes the circuit of the working motor E through the starting-resistance D. The switch J makes connexions at the same time for the forward rotation of the auxiliary motor F but the rotation does not occur, since the armature is short-circuited by the contacts m<1> of the relay with a winding connected between the contacts a<1>, l<1>. When the master controller is moved to the second notch, the contacts m<1> fall open and the motor F rotates the motor controller to cut out the first section of resistance. The auxiliary motor F is then stopped by a shortcircuit through the contacts m<2> closed by the second relay with a winding M<2> between the contacts a<2>, l<2>. Further movement of the master controller produces a similar action. In a modification, an interlock prevents the contactor B<2> from being closed again after being opened until the master controller has been returned to zero. An additional relay is arranged with its contacts in series with the auxiliary motor and operative in the latter positions of the master controller. This enables each of the short-circuiting relays M<1>, M<2>, M<3> to be used twice.