Method for aligning and starting a BLDC three phase motor

An integrated circuit (IC), comprising logic configured to operate a three phase motor, wherein the three phase motor comprises a rotor and a plurality of pairs of electromagnets, each pair of electromagnets of the plurality of pairs of electromagnets comprising a respective coil, wherein the logic is configured to:

• during an alignment period, when the roto is not rotating and a rotor position is not known:
• connecting a first coil of the respective coils to a high side drive and remaining coils of the respective coils to ground;
• apply pulse width modulation (PWM) to the first coil to control current in the respective coils;
• and
• once a designated PWM duty cycle is reached:
• releasing a coil of the respective coils that has been identified as not being required to move the rotor in a correct direction;
• apply PWM to unreleased coils of the respective coils, subsequent to releasing the identified coil, wherein as a result permanent magnet alignment is forced to be congruent the first coil and wherein said forcing of the permanent magnet alignment is in the correct direction of the rotor;
• and
• after said alignment phase:
• to perform forced commutation to further induce rotation of the rotor until feedback signal through a respective undriven coil is available.

A non-transitory computer readable memory medium comprising program instructions executable to operate a three phase motor, wherein the three phase motor comprises a rotor and a plurality of pairs of electromagnets, each pair of electromagnets of the plurality of pairs of electromagnets comprising a respective coil, wherein the program instructions are executable to:

• during an all alignment period, when the roto is not rotating and a rotor position is not known:
• to connect a first coil of the respective coils to a high side drive and remaining coils of the respective coils to ground;
• to apply pulse width modulation (PWM) to the first coil to control current in the respective coils;
• and
• once a designated PWM duty cycle is reached:
• to release a coil of the respective coils that has been identified as not being required to move the rotor in a correct direction;
• to apply PWM to unreleased coils of the respective coils, subsequent to releasing the identified coil, wherein as a result permanent magnet alignment is forced to he congruent to the first coil and wherein said forcing, of the permanent magnet alignment is in the correct direction or the rotor;
• and
• after said alignment phase:
• to perform forced commutation to further induce rotation of the rotor until feedback signal through a respective undriven coil is available, wherein the PWM duty cycle to the unreleased coils is increased while linearly decreasing time taken between commutations.

An electronic motor, comprising:

• a rotor comprising a permanent magnet;
• a stator comprising a plurality of pairs of electromagnets, each pair of electromagnets of the plurality of pairs of electromagnets comprising a respective coil;
• and
• logic configured to:
• during an alignment period, when the roto is not rotating and a rotor position is not known:
• connect a first coil of the respective coils to a high side drive and remaining coils of the respective coils to ground;
• apply pulse width modulation (PWM) to the first coil to control current in the respective coils;
• and
• when a designated PWM duty cycle is reached:
• to release a coil of the respective coils that has been identified as not being required to move the rotor in a correct direction;
• apply PWM to unreleased coils of the respective coils, subsequent to releasing the identified coil, wherein as a result permanent magnet alignment is forced to be congruent to the first coil and wherein said forcing of the permanent magnet alignment is in the correct direction of the rotor;
• and
• after said alignment phase:
• perform forced communication to further induce rotation of the rotor until feedback signal through a respective undriven coil is available, wherein PWM duty cycle to the unreleased coils is increased, and concurrently linearly decrease time taken between commutations.

A method for operating a motor, wherein the motor comprises a plurality of pairs of electromagnets, each pair of electromagnets of the plurality of pairs of electromagnets comprising a respective coil, the method comprising:

• when the rotor is not rotating, during an alignment phase prior to commutation, connecting a first coil of the respective coils to a high side drive and remaining coils of the respective coils to ground;
• applying pulse width modulation (PWM) to the first coil to control current in the respective coils, wherein the PWM is increased from an initial first predetermined duty cycle to a predetermined maximum PWM duty cycle;
• and
• once the predetermined maximum PWM duty cycle is reached:
• releasing a coil of the respective coils, wherein the released coil is not required to move the rotor in a correct direction;
• and
• applying PWM to unreleased coils of the respective coils, subsequent to said releasing, wherein said PWM to unreleased coils is decreased from the predetermined maximum duty cycle to a second predetermined duty cycle, wherein as a result permanent magnet alignment is forced to be congruent to the first coil;
• and
• performing forced commutation to further induce rotation of the rotor, wherein the PWM duty cycle to the unreleased coils is increased while linearly decreasing time taken between commutations.