Abstract: Embodiments of the present disclosure provide a method that comprises, based upon receipt of a mode command, changing an operating mode of a fan motor controller of a fan to a serial port communication protocol, programming a memory of the fan motor controller with an operating parameter of the fan, and based upon receipt of a serial port command, changing the operating mode of the fan motor controller from the serial port communication protocol to another protocol.

Abstract: A control system for a fan includes a control housing that is external to a fan housing for the fan. At least one fan control module is within the control housing and communicates remotely with terminals within the fan housing via at least one wire. The at least one fan control module includes a detection module. The detection module detects induced voltages in at least one of a plurality of stator coils within the fan housing via the at least one wire without receiving signals from a sensor in the fan housing.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: A motor control system includes a power control module and a detection module. The power control module controls power applied to first and second stator coils of a motor to rotate a rotor. The rotor induces voltages in the first and second stator coils when the rotor is rotating. The detection module determines a first time when a first voltage is induced in the first stator coil and determines a second time when a second voltage is induced in the second stator coil after the first voltage is induced. The detection module determines a speed of the rotor based on a difference between the first and second time. The power control module applies current through the second stator coil a predetermined period after the second time. The power control module determines the predetermined period based on the speed of the rotor.

Abstract: A system for controlling a rotational speed of a platter in a storage device. The system includes a mode selection module configured to select a mode operation for the storage device, in which the mode of operation includes at least i) a read/write mode in which data is to be read from or written to the platter, ii) a standby mode during in which data is not to be read from or written to the platter, or iii) a shutdown mode. The system further includes a speed control module configured to control the rotational speed of the platter based on the selected mode of operation for the storage device.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: A control system includes a position control module, a power control module, and a diagnostic module. The position control module applies a driving current for positioning a rotor of a motor at one of first and second positions. The power control module applies a first voltage to one of first and second phases of the motor to generate a first current after the position control module applies the driving current to position the rotor at the first position. The power control module applies a second voltage to one of the first and second phases to generate a second current after the position control module applies the driving current to position the rotor at the second position. The diagnostic module determines when the rotor is restricted from rotating based on the first and second currents.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: A control system includes a position control module, a power control module, and a diagnostic module. The position control module applies a driving current for positioning a rotor of a motor at one of first and second positions. The power control module applies a first voltage to one of first and second phases of the motor to generate a first current after the position control module applies the driving current to position the rotor at the first position. The power control module applies a second voltage to one of the first and second phases to generate a second current after the position control module applies the driving current to position the rotor at the second position. The diagnostic module determines when the rotor is restricted from rotating based on the first and second currents.

Abstract: Systems, methods, and other embodiments associated with back-EMF detection for motor control are described. In an embodiment, an apparatus includes a drive circuit configured to apply excitation signals to respective inputs of a motor, a signal inhibit circuit configured to convey a signal to inhibit application of the excitation signals during an interval, and a measuring circuit configured to measure a back-electromotive force (EMF) signal crossing a reference signal during the interval.

Abstract: A fan system includes a motor control module external to a motor housing of a fan assembly. The motor control module includes a speed control module. The fan assembly includes a fan and the motor housing. One or more first conductors are configured to connect the motor control module to a motor in the motor housing. One or more second conductors are configured to connect the motor control module to a host device control module. The host device control module is separate from the motor control module and is configured to generate a control signal. The speed control module is configured to control speed of the fan based on the control signal.

Abstract: A system includes a target speed module and a pulse-width modulation (PWM) control module. The target speed module is configured to provide a first waveform based on a first speed setting for a motor. A start of a first cycle of the first waveform corresponds to at least one of a first current or a first voltage. The PWM control module is configured to shift a phase of the first waveform by a torque angle adjustment value to generate a second waveform. A start of a first cycle of the second waveform corresponds to at least one of a second voltage or a second current. The second voltage is greater than the first voltage, and the second current is greater than the first current. The PWM control module is configured to control the motor based on the second waveform.

Abstract: A speed control system for a rotating storage device including a mode selection module configured to select an operating mode or a standby mode to operate the rotating storage device based on use of the rotating storage device and to select the standby mode after a first predetermined period during which reading and writing to the rotating storage device is not performed. The first predetermined period is selected based on a type of device in which the rotating storage device is implemented. The speed control system includes a speed control module configured to select a predetermined operating speed to rotate a storage medium of the rotating storage device when the operating mode is selected and to select a predetermined standby speed to rotate the storage medium when the standby mode is selected. The predetermined standby speed is (i) less than the predetermined operating speed and (ii) greater than zero.

Abstract: A method and apparatus for controlling the parking of a transducer head in a disk drive. A drive current is provided to a motor which controls movement of the head in a direction to move the head to a parking position. The arrival of the head at the parking position is detected. Upon this detection, a drive stop sequence is initiated to stop providing the drive current a short time after the head reaches the parking position. In one embodiment, it is determined whether the head has reached the parking position by monitoring the back emf (bemf) of the motor controlling the head, typically a voice coil motor (VCM). The detection of a sharp decline in the bemf indicates the head has stopped.

Abstract: Embodiments of the present disclosure provide a method that comprises, based upon receipt of a mode command, changing an operating mode of a fan motor controller of a fan to a serial port communication protocol, programming a memory of the fan motor controller with an operating parameter of the fan, and based upon receipt of a serial port command, changing the operating mode of the fan motor controller from the serial port communication protocol to another protocol.

Abstract: A motor control system includes a power control module and a detection module. The power control module controls power applied to first and second stator coils of a motor to rotate a rotor. The rotor induces voltages in the first and second stator coils when the rotor is rotating. The detection module determines a first time when a first voltage is induced in the first stator coil and determines a second time when a second voltage is induced in the second stator coil after the first voltage is induced. The detection module determines a speed of the rotor based on a difference between the first and second time. The power control module applies current through the second stator coil a predetermined period after the second time. The power control module determines the predetermined period based on the speed of the rotor.

Abstract: A control system for a fan includes a control housing that is external to a fan housing for the fan. At least one fan control module is within the control housing and communicates remotely with terminals within the fan housing via at least one wire. The at least one fan control module includes a detection module. The detection module detects induced voltages in at least one of a plurality of stator coils within the fan housing via the at least one wire without receiving signals from a sensor in the fan housing.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: A control system includes a position control module, a power control module, and a diagnostic module. The position control module applies a driving current for positioning a rotor of a motor at one of first and second positions. The power control module applies a first voltage to one of first and second phases of the motor to generate a first current after the position control module applies the driving current to position the rotor at the first position. The power control module applies a second voltage to one of the first and second phases to generate a second current after the position control module applies the driving current to position the rotor at the second position. The diagnostic module determines when the rotor is restricted from rotating based on the first and second currents.

Abstract: A method and apparatus for controlling the parking of a transducer head in a disk drive. A drive current is provided to a motor which controls movement of the head in a direction to move the head to a parking position. The arrival of the head at the parking position is detected. Upon this detection, a drive stop sequence is initiated to stop providing the drive current a short time after the head reaches the parking position. In one embodiment, it is determined whether the head has reached the parking position by monitoring the back emf (bemf) of the motor controlling the head, typically a voice coil motor (VCM). The detection of a sharp decline in the bemf indicates the head has stopped.