Abstract:
The present invention refers to a method for detecting the position of a rotor of a DC motor and to the relative circuit. According to an embodiment the method for detecting the position of a rotor of a DC motor (SM) with N phases having a plurality of windings (AV1, AV2, AV3), comprising the steps of: connecting at least two of said windings (AV1, AV2, AV3) between a first (Vcc) and a second (Gnd) prefixed voltage according to a first current path for a prefixed time (Tact); allowing the current stored in said two windings (AV1, AV2, AV3) to discharge through a second current path; comparing the voltage at the ends of one of said two windings (AV1, AV2, AV3) with a third prefixed voltage and providing a control signal when said voltage is smaller in absolute value than said third prefixed voltage; performing the above steps for each of the winding (AV1, AV2, AV3) couples of said motor (SM); detecting the position of said rotor on the base of the control signals obtained.
Abstract:
The present invention concerns a circuit for the speed recovery of a direct current motor comprising an output stage (1), consisting of a first couple of transistors (MOS1, MOS2) and of a second couple of transistors (MOS3, MOS4), and first means (5) for detecting a current circulating (Ivcm) in said motor. The inventive circuit has the characteristic of. comprising second means (7) suitable for activating said second couple of transistors (MOS3, MOS4) of said output stage (1) for a determined first time period (Tbrk) so as to short-circuit said motor (2), and at the end of said first time period (Tbrk) said second means (7) being suitable for unbalancing said output stage (1) so as to force the maximum current circulating (Ivcm) for a determined second time period (Tact) in function of the value detected by said first means (5) during said first time period (Tbrk) so as to stop said motor (2) in the shortest time possible.