A power tool is provided including a brushless DC (BLDC) motor, a rectifier that receives an alternative current from a power supply and outputs a rectified signal supplied to a DC power bus, and an inverter circuit having motor switches connected electrically between the DC power bus and the motor. A control module controls a switching operation of the power switches to regulate supply power from the power supply to the motor. The control module controls the switching operation so as to, within a half cycle of the AC power supply voltage waveform, increase current draw from the power supply from a first threshold at or after a first zero-crossing of the half cycle up to a second threshold, and reduce current draw from the power supply from the second threshold up to a third threshold at or prior to a second zero-crossing of the half cycle.

A power tool is provided including a brushless DC (BLDC) motor, a rectifier that receives an alternative current from a power supply and outputs a rectified signal supplied to a DC power bus, and an inverter circuit having motor switches connected electrically between the DC power bus and the motor. A control module controls a switching operation of the power switches to regulate supply power from the power supply to the motor. The control module controls the switching operation so as to, within a half cycle of the AC power supply voltage waveform, increase current draw from the power supply from a first threshold at or after a first zero-crossing of the half cycle up to a second threshold, and reduce current draw from the power supply from the second threshold up to a third threshold at or prior to a second zero-crossing of the half cycle.

A power factor correction circuit configured to increase the amount of useful power in an AC electrical system. The power factor correction circuit optionally includes one or more capacitors and one or more resistors configured to realign a phase angle between a voltage and current of an AC power source. Examples are offered illustrating the disclosed circuit in use with a single phase or multi-phase AC power source ranging in voltage from 100 volts or less to 500 volts or more.

A control apparatus includes a drive circuit unit to which regenerative electric power is input, a discharge resistance unit parallel-coupled to the drive circuit unit, to which the regenerative electric power is input from the drive circuit unit, and, when a voltage value of the regenerative electric power exceeds a threshold value, consuming electric power, a second converter circuit unit parallel-coupled to a first converter circuit unit and converting and outputting an alternating current into a direct current, a step-down circuit unit stepping down and outputting a voltage of the current output from the second converter circuit unit, an energization control circuit unit actuated by the direct current and controlling the drive circuit unit, and a regenerative electric power supply unit having a regenerative diode coupled to the discharge resistance unit and outputting a direct current of the regenerative electric power to the step-down circuit unit.

A control apparatus includes a drive circuit unit to which regenerative electric power is input, a discharge resistance unit parallel-coupled to the drive circuit unit, to which the regenerative electric power is input from the drive circuit unit, and, when a voltage value of the regenerative electric power exceeds a threshold value, consuming electric power, a second converter circuit unit parallel-coupled to a first converter circuit unit and converting and outputting an alternating current into a direct current, a step-down circuit unit stepping down and outputting a voltage of the current output from the second converter circuit unit, an energization control circuit unit actuated by the direct current and controlling the drive circuit unit, and a regenerative electric power supply unit having a regenerative diode coupled to the discharge resistance unit and outputting a direct current of the regenerative electric power to the step-down circuit unit.

A method for controlling a permanent magnet (PM) synchronous motor in an ESP application is provided. A load angle of the PM motor is estimated. A voltage adjustment value is determined for the PM motor based at least on the estimated load angle of the PM motor. A voltage to be applied to the PM motor is determined based on the voltage adjustment value.

A method for controlling a permanent magnet (PM) synchronous motor in an ESP application is provided. A load angle of the PM motor is estimated. A voltage adjustment value is determined for the PM motor based at least on the estimated load angle of the PM motor. A voltage to be applied to the PM motor is determined based on the voltage adjustment value.

A direct-current power supply apparatus includes: a reactor having one end connected to an alternating-current power supply; a bridge circuit, connected to an opposite end of the reactor, converting an alternating-current first voltage output from the alternating-current power supply into a direct-current voltage; and a current detector detecting an alternating current flowing between the alternating-current power supply and the bridge circuit. The reactor reduces an inductance in accordance with an increase of the alternating current and, when the alternating current exceeds a first current, has an inductance lower than one third of an inductance at which a current does not flow in the reactor. The bridge circuit performs an active operation when the detection value of the alternating current is larger than or equal to the first current and performs a passive operation when the detection value of the alternating current is lower than the first current.

Disclosed is a clothes treating apparatus and a control method thereof. Specifically, the clothes treating apparatus may include an inverter configured to convert a direct current (DC) input into an alternating current (AC) output and provide the AC output to the motor, and a controller configured to control the inverter in relation to driving of the motor.

Disclosed is a clothes treating apparatus and a control method thereof. Specifically, the clothes treating apparatus may include an inverter configured to convert a direct current (DC) input into an alternating current (AC) output and provide the AC output to the motor, and a controller configured to control the inverter in relation to driving of the motor.