Standard Microsystems Corporation

James P McFarland

Lynn Russell Kern

Timothy J Knowlton

Christopher Fischbach

Joe A Marrero

System and method for initiating rotation of a rotor in a motor. The motor may include the rotor and a plurality of pairs of electromagnets. A rotation period may be determined. One or more pairs of electromagnets of the plurality of pairs of electromagnets may be excited at a first excitation level. The excited one or more pairs of electromagnets may be determined based on the rotation period. The excitation level may be decreased, over a first period of time, to a second excitation level. The second excitation level may be a lower excitation level than the first excitation level. The excitation level may be increased, over a second period of time, to a third excitation level. The third excitation level may be a higher excitation level than the second excitation level. The rotation period may be decreased over the first and second periods of time.

System and method for inducing rotation of a rotor in a sensorless motor

An emulation system for charging any arbitrary portable device through a communication port on the portable device. The system includes a receptacle port for communicating with the portable device and a profile database for storing multiple charging profiles. Each charging profile including a set of parameters and at least one exit condition. Further, an emulation module applies a first charging profile to the portable device and monitors the set of parameters associated with the charging profile to identify an associated exit condition. Upon a determination that the exit condition for the first charging profile is met, the emulation module applies a next charging profile to the portable device.

Method and system for sampling multiple profiles in a charging port without host intervention

A motor includes a rotor and a plurality of pairs of electromagnets. The energy needed for alignment of the rotor is used to generate the first movement in forced commutation and may be combined with the initial energy to start the motor. The logic is configured to align the rotor by energizing the three coils of the motor. PWM is applied to the first coil to control current on the coils; when a maximum PWM duty cycle is reached, the coil not required to rotate the correct direction are released, thereby initiating motion in a rotor. A rotation period is determined. One or more pairs of electromagnets are excited at a first excitation level which may be increased, over a second period, to a second level. The second level may be a higher level than the first level. The rotation period may be decreased over the first and second periods.

Method for aligning and starting a BLDC three phase motor

A control method for a sensor-less, brushless, three-phase DC motor. The effects of commutation on the motor may be minimized using a sinusoidal current drive on each electromagnet. The 'off' times and/or the 'on' times of the drive transistors controlling the electromagnets in a full &#x201c;H-bridge&#x201d; configuration drive scheme may be delayed. By overlapping the drive signals to the electromagnets with respect to a commutation command, the effects of switching between electromagnets may be minimized. In addition, the &#x201c;on&#x201d; and &#x201c;off&#x201d; times may also be adjusted during the overlapping to further ensure that the coils continuously conduct current, and that the current does not change direction during the switching. The delays, and hence the overlap times of the coil drive signals may be dynamically controlled, for example by using digital timers, making the response predictable and easily controlled. The present position of the rotor in the motor may be determined using Hall sensors configured in the motor, or it may be determined using the un-energized electromagnets in a motor without Hall sensors.

Drive method to minimize vibration and acoustics in three phase brushless DC (TPDC) motors

A control method for a brushless, three-phase DC motor. The motor may include a plurality of electromagnets and a rotor. A voltage induced by rotation of a rotor may be sampled at an expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values, may be calculated. A delta zero crossing error may be calculated. The delta zero crossing error may be calculated based on a difference between the first sampled voltage value and the calculated average. The plurality of electromagnets may be commutated. Commutation timing for the plurality of electromagnets may be determined based at least in part on the delta zero crossing error.

Brushless three phase motor drive control based on a delta zero crossing error

A control method for a sensor-less, brushless, three-phase DC motor. A pulse-width modulation (PWM) duty cycle may be calculated. A voltage induced by rotation of a rotor may be sampled at a first expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values and the first sampled voltage value, may be calculated. The first sampled voltage value may be subtracted from the calculated average to produce a delta zero crossing error. The delta zero crossing error may be multiplied by a first constant representing electromechanical properties of the motor to produce a representation of an angular velocity. One or more time values may be generated based on the representation of the angular velocity. Operation of the motor may be controlled based on the one or more time values and the PWM duty cycle.

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Tucson, AZ, United States of America

James P McFarland