Abstract: The commutator of the motor is made up of three parts assembled coaxially and insulated from one another. Each part is connected to one of the windings of the rotor. The parts are blanked from a sheet of metal, preferably silver, with a flat annular zone, an inner lug, and radial fingers which are subsequently all bent at a 90.degree. angle at the same side of the annular zone. The parts are fitted into each other in such a way that the fingers of the different parts are seated around the circumference of the commutator.

Abstract: The motor (9) comprises a motor winding with two phases (2, 3). Sensor c detects the orientation of the permanently magnetized rotor. Selector (S) controlled by line (s) which can be connected to a memory (M) selects the sending to circuit (C) of clock pulses (H) or signals (G) coming from circuits (F) which receives the pulses emitted by sensor (c). In circuit (C) the signals received from the selector are processed and shaped into control signals which act in the power stage of circuit (P) upon each of the two phases (2, 3) by triggering and releasing them alternately in such a way as to ensure that the operation of the rotor occurs either in step mode, under the influence of the clock signals (H), or in direct current mode, i.e., as a function of the momentary position of the rotor as it is detected by sensor (c).

Abstract: An electromechanical transducer comprises a fixed part and a part rotatable about an axis. One of these parts includes an assembly of aircore coils which are distributed about the axis. Each coil is divided into two parts, each of which comprises two active coil segments intersected by the magnetic field upon rotation of the transducer. The two parts of each coil are furthermore arranged so that the effects of mutual inductance of the active coil segments of one coil part upon the other are reversed relative to the effects of self-inductance in each part.