Patent ID: 6859002

Claim:
A device for controlling an electric motor of the electronic switching type comprising N pairs of poles and P phases, the said device comprising: a coder ( 2 ) designed to be rotated conjointly with the rotor ( 1 ) of the motor, said coder comprising a main multipole track ( 2 a ) and a multipole track ( 2 b ) which are concentric, said revolution pip track comprising N singularities ( 2 b 1 ) equally distributed angularly; a fixed sensor ( 3 ) disposed opposite to and at an air-gap distance from the coder ( 2 ), comprising at least three first sensitive elements, at least two of which are positioned opposite the main track ( 2 a ) so as to deliver two periodic electrical signals S 1 , S 2 in quadrature and at least one of which is positioned opposite the revolution pip track ( 2 b ) so as to deliver an electrical signal S 3 , the sensor ( 3 ) further comprising an electronic circuit able, from the signals S 1 , S 2 and S 3 , to deliver two square digital position signals (A, B) in quadrature which represent the angular position of the rotor ( 1 ) and a revolution pip signal (C) in the form of N pulses per revolution of the coder ( 2 ); a circuit for switching the currents in the phase windings of the motor which comprises 2*P*N switches; a circuit for controlling the switching circuit which is able: when a pulse of the revolution pip signal (C) is detected, to determine the state of the switching logic of the currents in the phase windings which corresponds to the angular position of the pulse; according to the position signals (A, B) detected, to determine continuously the state of the switching logic which is adapted to the angular position of the rotor ( 1 ); to supply the switching signals for the switches which correspond to the state of the logic determined by the revolution pip signal (C) or by the position signals (A, B).