Abstract: The commutator of a DC motor is uniquely constructed to include at least one dead segment at least as wide as the associated brush (brushes). A silicon controlled rectifier (SCR) is arrranged in the circuit between the voltage source and said brush (brushes) to provide a switching means to automatically cut off current flow therethrough each time a brush passes over the dead segment. The current is reestablished by way of a gating means, which in the preferred embodiment is a variable frequency pulse generator.

Abstract: The commutator or commutators of a DC motor are uniquely arranged with a plurality of peripherally spaced, current carrying segments separated by relatively large, electrically dead, non-conducting spaces, each of the dead spaces being at least as wide in a peripheral direction as the corresponding width dimension of the brushes positioned adjacent thereto. A silicon controlled rectifier (SCR) is arranged in the circuit between the negative pole of the voltage source and the commutator input terminal and acts as a switch to automatically cut off current flow therethrough each time a brush leaves a commutator segment. The current is not re-established until the SCR is again gated, which time may be varied by a variable resistor/capacitor gating circuit.To prevent stoppage of the motor with the brushes of the commutator in a dead space a plurality of commutators are provided with the segments thereof staggered with relation to the first.