A relatively new type of motor which has a stationary armature, wound with a number of independent coils, is the subject of the paper. Its coils are connected in parallel to the supply via thyristors, which are used to control the time intervals during which currents are allowed to flow in the coils. The stator is slotless, and its coils are wound to form a ring-type winding. Alternating- or direct-voltage sources can be applied to the armature of the motor. In the machine being discussed, alternating voltage is applied for starting and low speed, and direct voltage for normal running, which, in this case, is from 600 to 3550rev/min. When a direct voltage is applied, induced-e.m.f. commutation is used to cut off the coil thyristors.