Texas Instruments Incorporated
Operational mode control of a motor

Abstract:

One example is a system for controlling a motor during startup. The system includes measurement logic, pattern detection logic, and mode logic. The measurement logic monitors a back-electromotive force (BEMF) signal representing a BEMF of an electric motor and the pattern detection logic monitors this signal to detect instances of the monitored BEMF signal exhibiting a predetermined pattern. The mode logic enables control of the electric motor according to a plurality of modes of control. In some examples, the mode logic initially employs a first mode of control and switches from the first mode of control to a second mode of control in response to the pattern detection logic detecting that a BEMF signal exhibits the predetermined pattern over a plurality of commutation states.