Back to results
US 2001/0040438 A1Published application
Control of a brushless motor
AssigneeSTMicroelectronics S.r.l.
InventorsBRUNO MAURICE, JEAN-MARIE CHARRETON
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeSTMicroelectronics S.r.l.
InventorsBRUNO MAURICE, JEAN-MARIE CHARRETON
Estimating the term…
A method and apparatus for controlling a brushless motor having a plurality of windings switched through a sequence of steps includes determining a transition time from one step to the next. The transition time is determined by detecting a zero crossing of a back emf in one of the plurality of windings. A delayed time to be added to the transition time is determined wherein the delayed time is selected according to the step in the sequence of steps being executed and is dependent on the duration of one of a preceding interval between zero crossings. A delay time proportional to a duration of a last shortest interval is supplied to follow a longest interval. A delay time proportional to a duration of a last longest interval is supplied to follow a shortest interval and a delay time proportional to a duration of a medium interval is supplied to follow a medium interval. The method may be used, for example, with a star or delta connected motor having any number of windings.
A self-commutated type method of control of a brushless motor having a plurality of windings switched according to a determined cycle of steps, in which each transition between steps is determined at a time following a zero crossing of a back emf by a determined delay, wherein the delay is chosen selectively according to the step involved, depending on the duration of a determined one of preceding intervals between zero crossings.
A method for controlling a brushless motor having a plurality of windings switched through a sequence of steps, the method comprising:
A circuit for controlling a brushless motor comprising:
Dependencies are inferred from the claim text.