Patent ID: 6337554
Filing Date: 2002-01-08
Classification: H02P

Abstract:
A device for controlling an electric motor provided with a rotor fitted with a permanent magnet magnetically coupled to at least first, second and third stator coils connected to first, second and third connection terminals, said device including:means for providing, via first, second and third output terminals, first, second and third respective control signals to said first, second and third connection terminals of said motor, respectively, said signals being periodic at a control frequency; and detecting means for detecting an angular position of the rotor; wherein said detecting means includes: measuring means arranged to be able to be connected to said first, second and third connection terminals, said measuring means forming with said first, second and third stator coils at least first and second oscillating circuits having respectively first and second distinct electric configurations, so that the first and second oscillating circuits can provide respectively first and second periodic measurement signals having first and second frequencies, respectively, that are substantially higher than said control frequency and that vary periodically with the angular position of said rotor, at a period corresponding to a complete rotation of the rotor divided by the number of poles of said permanent magnet; and calculating means arranged to receive the first and second measurement signals, calculate said angular position from the couple formed by the first and second frequencies of said signals and to provide a value of said angular position.