The present application relates to a motor control technology, and in particular to a start-up device for a DC motor, a motor system comprising the start-up device, a method for reducing DC motor start-up current and a computer-readable storage medium with a computer program stored thereon for implementing the above method. The start-up device for a DC motor according to one aspect of the present application includes: a switching element connected in series within a circuit comprising the DC motor and a DC power supply; and a control unit configured to cause the switching element to periodically switch between an ON state and an OFF state in a predetermined time interval to reduce the peak value of a start-up current flowing through the DC motor, and to cause the switching element to maintain the ON state after the predetermined time interval ends.

The present application relates to a motor control technology, and in particular to a start-up device for a DC motor, a motor system comprising the start-up device, a method for reducing DC motor start-up current and a computer-readable storage medium with a computer program stored thereon for implementing the above method. The start-up device for a DC motor according to one aspect of the present application includes: a switching element connected in series within a circuit comprising the DC motor and a DC power supply; and a control unit configured to cause the switching element to periodically switch between an ON state and an OFF state in a predetermined time interval to reduce the peak value of a start-up current flowing through the DC motor, and to cause the switching element to maintain the ON state after the predetermined time interval ends.

A motor driving apparatus includes a driving circuit that drives a motor based on a driving instruction signal at a first state of the first state and a second state which are binarized, a current feedback circuit including a latch circuit, and a controller that outputs the driving instruction signal and a current command signal. The latch circuit latches a third state of the third state and a fourth state which are binarized if a motor current value exceeds a current command value. When the driving instruction signal becomes the second state, the latch circuit releases the latching of the third state and outputs a signal of the fourth state. The controller outputs the driving instruction signal of the second state along with the current command signal so as to release the latching of the latch circuit when outputting the current command signal with the current command value changed.

A movable partition system includes a movable partition including coupled panels and a lead post engaged with and movable along a track. A motor control system includes a motor coupled to the movable partition and a switching circuit coupled to the motor and for selectively coupling the motor to a positive power source and a negative power source responsive to one or more PWM signals. An encoder is configured for generating one or more rotation signals indicative of operational direction and operational speed of the motor. A motor controller is coupled to the switching circuit and is configured for improving airflow around the panels of the movable partition when the lead post of the movable partition is between a predefined position and a fully retracted position indicative of a billowing effect for the panels by adjusting pulse widths of the PWM signals to control rotational speed of the motor.

A movable partition system includes a movable partition including coupled panels and a lead post engaged with and movable along a track. A motor control system includes a motor coupled to the movable partition and a switching circuit coupled to the motor and for selectively coupling the motor to a positive power source and a negative power source responsive to one or more PWM signals. An encoder is configured for generating one or more rotation signals indicative of operational direction and operational speed of the motor. A motor controller is coupled to the switching circuit and is configured for improving airflow around the panels of the movable partition when the lead post of the movable partition is between a predefined position and a fully retracted position indicative of a billowing effect for the panels by adjusting pulse widths of the PWM signals to control rotational speed of the motor.

A method for operating an electric motor connectable via a switching device to a current source and connected in parallel with a freewheeling device, the switching device having control applied to it at a specific activation ratio within each working cycle to establish a desired effective operating voltage of the electric motor, so that in at least one operating mode each working cycle is includes an activation and a freewheeling time period. The freewheeling device has a freewheeling transistor and a freewheeling diode, connected in parallel with the transistor and reverse-biased as to the current source; and control is applied to the freewheeling transistor in the freewheeling time period as follows: identifying the freewheeling voltage dropping across the electric motor; and switching the freewheeling transistor for a specific switching time period if the freewheeling voltage is different from zero, particularly less than zero. Also described is an electric motor device.

A multiphase motor driving circuit includes: a power stage circuit; and a control circuit. In a motor braking mode, when a holding voltage is less than the first voltage threshold, a first sub-mode is entered, in which the control circuit controls at least a portion of switches in the power stage circuit with a pulse width modulation (PWM) signal to switch periodically, thereby converting a back electromotive force (EMF) of a multiphase motor into the holding voltage to supply power to the control circuit. In the motor braking mode, when the holding voltage is greater than the second voltage threshold, a second sub-mode is entered, in which the control circuit controls at least a portion of switches in the power stage circuit with the PWM signal to keep them continuously conductive, thereby consuming the back EMF of the multiphase motor to reduce a speed of the multiphase motor.

A multiphase motor driving circuit includes: a power stage circuit; and a control circuit. In a motor braking mode, when a holding voltage is less than the first voltage threshold, a first sub-mode is entered, in which the control circuit controls at least a portion of switches in the power stage circuit with a pulse width modulation (PWM) signal to switch periodically, thereby converting a back electromotive force (EMF) of a multiphase motor into the holding voltage to supply power to the control circuit. In the motor braking mode, when the holding voltage is greater than the second voltage threshold, a second sub-mode is entered, in which the control circuit controls at least a portion of switches in the power stage circuit with the PWM signal to keep them continuously conductive, thereby consuming the back EMF of the multiphase motor to reduce a speed of the multiphase motor.

A motor driving apparatus for a cleaning appliance includes a battery source and a power controller. The battery source supplies the power controller with an output having a first voltage which decreases as the battery source is discharged. The power controller modulates the output to produce a drive signal for driving a motor that has a second voltage and a variable duty cycle. The power controller increases the duty cycle of the drive signal as the first voltage decreases in order to maintain the second voltage at a substantially constant average value per unit time. By providing the above arrangement, the motor can be supplied with a constant voltage throughout the available run time of the battery. When forming part of a cleaning appliance having a motor, the above arrangement allows the motor to operate at a substantially constant speed throughout the run time of the battery.

A power tool includes a working component configured with the maximum output rotational speed; an electric motor configured with the maximum rotational speed; a transmission assembly configured with a transmission ratio; a driver circuit including one or more drive switches; and a controller for outputting a control signal to control the one or more drive switches of the driver circuit. At least one drive switch in the driver circuit includes a wide bandgap semiconductor switch, and the ratio of the required maximum rotational speed of the electric motor to the maximum rotational speed of the electric motor is less than or equal to 0.9. The electric motor system of the power tool has good electrical performance.