Control circuit for a half-wave brushless motor with a surge limiter
AssigneeIndustrie Magneti Marelli S.r.l.
InventorsFranco Salerno, Pietro De Filippis
Life of this patent
Estimating the term…
Abstract
A control circuit for a half-wave brushless motor. The control circuit includes n circuit branches, each with an electronic power switch connected in series with the respective winding or phase of the motor across the terminals of a voltage source in parallel to the other n-1 circuit branches, a pilot circuit for providing enabling signals to render the power switches selectively conductive, current recirculation elements for dissipating transient current that flows in each phase of the motor whenever the associated power switch is turned off, and a voltage limiter for limiting, to a predetermined threshold voltage, the voltage surge due to the transient current.
Claims4
A control circuit for half wave brushless motor, comprising:
- an assembly of n circuit branches, each of which includes an electronic power switch connected in series with a respective winding or phase of the motor, between the terminals of a DC voltage source, and in parallel with the other n-1 circuit branches;
- pilot circuit means for providing an enabling signal that renders said electronic switches selectively and cyclicly conductive in a predetermined manner;
- current recirculation means connected to the phases of the motor to drain transient current that circulates in each phase of the motor whenever the associated electronic power switch is turned off;
- and
- voltage limiter means for limiting to a predetermined threshold voltage the voltage surge developed in each phase of the motor by said transient current;
- said threshold voltage varies proportionally with the average of the superimposition envelope of the back electromotive forces developed in each phase of the motor.
Dependencies are inferred from the claim text.