A motor control unit controls a driving current that flows through a coil of a motor to be driven, by controlling a PWM signal supplied to an H bridge circuit constituted by FETs. A current value generation unit detects a driving current based on a voltage that occurs across a current detection resistor, and corrects a detection value by using a first or second correction value. The current value generation unit, if the driving current is detected in the H period of the PWM signal, corrects the detection value by using the first correction value, and if the driving current is detected in the L period of the PWM signal, corrects the detection value by using the second correction value that has a polarity different from a polarity of the first correction value.

A power tool is configured to receive power from a power supply. The power tool may include a rectifier that may output a rectified signal to a DC power bus. A switching arrangement may operate to deliver electric power from the DC power bus to an electric motor. A switch path may be electrically coupled in parallel with the rectifier on the DC power bus. The switch path includes an auxiliary capacitor in series with a switch and a state of the switch controls a discharging path for the auxiliary capacitor. A switch control circuit may be configured to detect voltage associated with at least one of the AC power supply or the DC power bus and to control state of the switch in accordance with magnitude of the detected voltage.

An integrated gate driver for motor control includes a first diode coupled to an upper rail and providing a voltage on a first connector and a power amplifier coupled between the first connector and a second connector that can be coupled to a source of a high-side power transistor. The power amplifier receives a control signal and provides an output signal to a second pin for driving a gate of the high-side power transistor. A first integrated capacitor is coupled between the first and second connector and an integrated charge pump is coupled to supply a current to the first connector. The charge pump includes a second integrated capacitor having a terminal coupled to a high frequency oscillator and a terminal coupled through a second diode to the first connector and a third diode coupled between the second connector and a point between the second capacitor and the second diode.

A rotational speed command output unit receives and outputs a command value of a motor rotational speed inputted from outside. A PWM duty calculator calculates a PWM duty based on the command value and an actual rotational speed of a motor. A maximum speed estimator estimates, based on the actual rotational speed measured, a parameter representing a controlled state of the motor, a current PWM duty and a predetermined upper limit of the PWM duty, a maximum rotational speed of the motor to be reached under PWM control with the upper limit of the PWM duty. The command value inputted from outside is restricted not to exceed the maximum rotational speed. In this way, when a motor is PWM-controlled, abrupt changes in the rotational speed of the motor due to supply voltage fluctuations can be suppressed.

A current controller for an electric machine that includes an input, an output, a threshold generator and a comparator. The threshold generator stores a scaling factor and includes a PWM module that operates on a reference voltage to generate a threshold voltage. The duty cycle of the PWM module is then defined by the scaling factor. The comparator compares a voltage at the input against the threshold voltage and causes an overcurrent signal to be generated at the output when the voltage at the input exceeds the threshold voltage.

A method of controlling an electric machine, the method comprising storing a plurality of power maps, each power map comprising control values for driving the electric machine at different power, and selecting a power map in response to an input signal. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

The invention relates to a control circuit (1) of an electric motor (4), the control circuit (1) comprising a filtering device (13) in order to filter the high frequencies likely to produce perturbing electromagnetic radiation when the electric motor (4) is driven. To this end, the filtering device (13) comprises one or more filtering capacitors (132A-132D) branched off from a power bridge (12) driving the electric motor (4), at least a proportion of the filtering capacitors (132A-132D) being of the polymer-hybrid type in order to improve the dynamic performance of the filtering device (13) and to reduce its size.

The invention also relates to a motorized-fan unit (8) for motor vehicles comprising such a control circuit (1).

A driver circuit is provided for driving a load, such as a multi-phase motor. The driver circuit includes a gate driver for providing a control signal to switching elements coupled to the driver circuit. A first switching element is coupled between a high supply voltage and a switching node of the load, and a second switching element is coupled between the switching node and a low supply voltage. To detect zero crossings of a current through the load, a zero crossing detector includes a first counter coupled to the switching node and a second counter coupled to the control signal. The first counter and second counter count in a predetermined direction based on a detected voltage of the switching node and based on a detected voltage of the control signal, respectively. The zero crossing detector generates an output signal based upon the difference between the first and the second counter.

A cleaner includes a BLDC motor and a power unit. The BLDC motor includes a rotor and a stator provided with a DC coil and an AC coil in a separate manner. The power unit is configured to supply DC power and AC power to the DC coil and the AC coil, respectively.

Disclosed are a control apparatus for dynamically adjusting a phase switching of a DC motor and a method thereof. A rotor in the DC motor is divided into 2 M pole areas, wherein M is a positive integer not less than 1. The control apparatus comprises a phase detector, a current detector, a control circuit and a driving circuit. The phase detector detects the phase switching state of the pole areas to generate a standard phase signal. The current detector detects a current flowing through the DC motor in one of switching points of the standard phase signal to generate a current detection value. The control circuit periodically outputs 2 M drive signals, and determines to perform dynamically adjusting operation on the timing sequence of the drive signals according to the current detection value. The driving circuit receives the drive signals to perform the phase switching for driving the DC motor.