A power tool is provided including a brushless direct-current (BLDC) electric motor having a stator and a rotor. The power tool includes power switches including high-side switches and low-side switches disposed on a direct-current (DC) bus line between a power supply and the electric motor, and a controller configured to electronically brake the motor by simultaneously closing the high-side switches or the low-side switches to electrically short the stator windings. In an embodiment, the controller is configured to monitor a voltage of the DC bus line, and if the voltage of the DC bus line is lower than a voltage threshold, execute electronic braking by toggling between closing the high-side switches and closing the low-side switches over braking cycles, and if the voltage of the DC bus line is greater than the voltage threshold, execute braking by closing only the high-side switches or the low-side switches over the braking cycles.

A motor control device including a PWM control part is provided. The PWM control part has a two-phase complementary PWM control part, and when driving opening and closing of an opening/closing body, PWM-controls upper switching elements and lower switching elements of three phases in a three-phase inverter circuit based on an energization mode that sequentially switches among energized phases, which are two of the three phases, and a non-energized phase, which is a remaining one phase. The two-phase complementary PWM control part, in one of the energized phases, controls one of the upper switching element and the lower switching element by a PWM signal, and controls the other by a complementary PWM signal having a polarity opposite to the PWM signal, and, in the non-energized phase, controls one of the upper switching element and the lower switching element to be off, and controls the other by the complementary PWM signal.

A motor control device including a PWM control part is provided. The PWM control part has a two-phase complementary PWM control part, and when driving opening and closing of an opening/closing body, PWM-controls upper switching elements and lower switching elements of three phases in a three-phase inverter circuit based on an energization mode that sequentially switches among energized phases, which are two of the three phases, and a non-energized phase, which is a remaining one phase. The two-phase complementary PWM control part, in one of the energized phases, controls one of the upper switching element and the lower switching element by a PWM signal, and controls the other by a complementary PWM signal having a polarity opposite to the PWM signal, and, in the non-energized phase, controls one of the upper switching element and the lower switching element to be off, and controls the other by the complementary PWM signal.

The invention relates to a control unit (1) for a motorized device (10) comprising: a brushless motor (20), a power supply (30), an operating unit (40), which can be activated by a user, wherein the control unit (1) is designed at least for controlling the commutation of the motor (20) by a plurality of circuit breakers (12, 13, 14, 15, 16, 17) connected to the power supply, and for initiating an electronic (i.e. in particular non-mechanical) braking of the motor, wherein the control unit (1) is deactivated, i.e. switched off, for a rotational speed-dependent duration to by means of a position sensor (50) and is held until then in an active switched-on operating state and, dependent thereon, a control means (60) is provided then to initiate, under automatic control, the shutdown of the device (10).

A method is provided for electrically driving a motor having a plurality of phase windings such that EMC (electromagnetic compatibility) is improved and the running performance of the motor is simultaneously kept constant. At least one of the phase windings is not supplied with a current pulse during a complete revolution of the rotor, or at least one switchable electrical resistor is switched on, for at least one subsequent commutation phase by means of an electrical switching element, if the detected rotor speed is greater than the specified target speed.

The present invention provides a motor driver and a motor driving system capable of suppressing power consumption when a motor is in a brake state. The motor driver of the present invention includes: a half-bridge power output section, including a high-side transistor and a low-side transistor; a high-side driving circuit, driving the high-side transistor; and a control portion. When switching to a brake mode, the low-side transistor is turned on and the control portion turns off the high-side driving circuit.

The brake driving control circuit, which controls an electromagnetic brake that releases the brake by applying a current, is provided with: a first rectifying element provided between a first power supply of a first circuit voltage and one terminal of the electromagnetic brake; a cut-off switch inserted into a line through which the first power supply supplies power; a first switching element provided between the other terminal of the electromagnetic brake and a ground point; and a second switching element and a second rectifying element provided in series between a second power supply of a second circuit voltage, which is different from the first circuit voltage, and the one terminal of the electromagnetic brake.

The brake driving control circuit, which controls an electromagnetic brake that releases the brake by applying a current, is provided with: a first rectifying element provided between a first power supply of a first circuit voltage and one terminal of the electromagnetic brake; a cut-off switch inserted into a line through which the first power supply supplies power; a first switching element provided between the other terminal of the electromagnetic brake and a ground point; and a second switching element and a second rectifying element provided in series between a second power supply of a second circuit voltage, which is different from the first circuit voltage, and the one terminal of the electromagnetic brake.

A wiper motor control circuit controls a drive circuit such that an actual speed of a wiper speed computed based on change in a rotation angle of an output shaft of the wiper motor detected by a rotation angle sensor that detects the rotation angle becomes a target speed corresponding to a position of a wiper blade indicated by the rotation angle detected by the rotation angle sensor. The wiper motor control circuit also controls the drive circuit so as to apply a braking current in the wiper motor when the actual speed has exceeded a threshold value when the rotation angle detected by the rotation angle sensor indicates a return position of the wiper blade.

The present invention relates to an emergency control device for a spring return valve actuator, the device including: a power source unit for receiving an alternating current (AC) power source, converting and stepping down an AC voltage of the received AC power source to a given direct current (DC) voltage, and supplying the DC voltage, and transmitting a signal as to whether the power source is supplied; a charge unit for receiving the DC voltage from the power source unit to store electrical energy with a given voltage; and a control unit for receiving the DC voltage from the power source unit to supply the received DC voltage to the electromagnetic brake, and if a power source cutoff signal is received from the power source unit, for supplying the electrical energy stored in the charge unit to the electromagnetic brake for a given set time.