Abstract: A contactless electronic control system particularly adapted to drive a motorized wheel hub includes a tubular bracket and a tubular grip member encircling the bracket and connected thereto by a rotary connection so that the grip member can rotate about the bracket. A ring magnet having diametrically opposite poles is mounted in the grip member for rotation therewith and a Hall Effect device is mounted to the bracket. When the grip member is rotated in one direction so as to move one of the poles toward the device, the device produces a proportional positive electrical signal and when the grip members rotated relatively in the opposite direction so as to move the other of the poles toward the device, the device produces a proportional negative signal. Preferably, the magnet is positioned between concentric inner and outer pole pieces and the grip member is biased to a home position which locates the magnets poles on opposite sides of the sensor.