Control system for an electronically commutated motor (ECM). The ECM includes a stationary assembly having a plurality of winding stages adapted to be selectively commutated, and rotatable means associated with the stationary assembly in selective magnetic coupling relation with the winding stages. A circuit commutates the winding stages by selectively supplying power thereto in response to a pattern of control signals leaving at least one of the winding stages unpowered at any one time while the other winding stages are powered. The control system includes a circuit coupled to the winding stages for simultaneously converting the voltages across the winding stages to digital form thereby to digitize the voltages, and a circuit for producing successive patterns of digital signals in at least one preselected sequence, for selecting the digitized voltage across the at least one unpowered winding stage depending on the digital signal pattern produced, and for producing a following pattern in sequence after at least one predetermined logic level of the selected digitized voltage has occurred. Another circuit responds to the successive patterns of the digital signals for generating the successive patterns of the control signals for the commutating circuit.