Patent ID: 9385641
Filing Date: 2016-07-05
CPC Classification: H02P

Claim Text:
1. A method for initiating rotation of a rotor in a motor, wherein the motor comprises the rotor and a plurality of pairs of electromagnets, the method comprising: determining a rotation period; exciting one or more pairs of electromagnets of the plurality of pairs of electromagnets at a first excitation level, wherein the excited one or more pairs of electromagnets are determined based on the rotation period; decreasing, over a first period of time, the excitation level to a second excitation level, wherein the second excitation level is a lower excitation level than the first excitation level; increasing, over a second period of time, the excitation level to a third excitation level, wherein the third excitation level is a higher excitation level than the second excitation level; decreasing, over the first and second periods of time, the rotation period; wherein the motor is configured to use an undriven electromagnet of the plurality of pairs of electromagnets to indirectly detect a position of the rotor, wherein the indirect detection requires rotation of the rotor; wherein said exciting the one or more pairs of electromagnets, decreasing the excitation level to the second excitation level over a first period of time, increasing the excitation level to the third excitation level over a second period of time, and decreasing the rotation period over the first and second periods of time, initiate rotation of the rotor in the motor without knowledge of an exact position of the rotor.