A safety device for an actuator that can modulate power to an electric motor in response to a fault condition (e.g., stall). In one embodiment, the actuator can include a motor with a shaft, a sensor disposed in proximity to the shaft, and a control processor coupled with the sensor and the motor. The control processor can be configured to receive a signal from the sensor that conveys operating data that relates to rotation of the shaft, use the operating data to identify a fault condition on the motor, and change the motor from an energized condition to a de-energized condition in response to the fault condition.

A motor drive circuit comprising two or more inverters to provide current to a permanent magnet motor. Each inverter includes a respective switch arm comprising one or more switches for each phase of the motor to be driven. The motor drive circuit includes means for detecting a switch short circuit for any switch within one of the inverters and means for determining the speed of the motor. The motor drive circuit further includes a controller configured to short circuit each switch arm of the inverter containing the switch short circuit if the motor speed exceeds a predetermined threshold, but not if the motor speed does not exceed the predetermined threshold.

A motor drive circuit comprising two or more inverters to provide current to a permanent magnet motor. Each inverter includes a respective switch arm comprising one or more switches for each phase of the motor to be driven. The motor drive circuit includes means for detecting a switch short circuit for any switch within one of the inverters and means for determining the speed of the motor. The motor drive circuit further includes a controller configured to short circuit each switch arm of the inverter containing the switch short circuit if the motor speed exceeds a predetermined threshold, but not if the motor speed does not exceed the predetermined threshold.

An electronically commutated motor driving module for driving a motor includes a voltage detector, an electronically commutated motor driver, a current detector, a voltage converter, and a controller. The voltage detector detects supply voltage to generate a voltage detection signal. The electronically commutated motor driver is supplied by the supply voltage to generate, according to an electronically commutated signal, an operating current for driving the motor. The current detector detects the operating current to generate a current detection signal. The voltage converter converts the supply voltage into an internal voltage. The controller is supplied by the internal voltage and generates the electronically commutated signal according to a plurality of control parameters. When the controller determines that a specific event has happened according to the control parameters, the controller stops generating the electronically commutated signal and then stores the control parameters.

An electric motor control system includes a master control module, a drive module, and a monitoring module. The master control module is configured to output a low-voltage drive signal to the drive module, the drive module converts the low-voltage drive signal into a high-voltage drive signal and outputs the high-voltage drive signal to a power unit, and the power unit outputs, according to the high-voltage drive signal, a power supply drive signal provided by a high-voltage battery. The monitoring module is electrically connected with the master control module and the drive module, and is configured to acquire the low-voltage drive signal, and output a fault signal to the master control module when the low-voltage drive signal is abnormal, to control the master control module to stop outputting the low-voltage drive signal.

An opening/closing member driving device includes a motor that opens and closes an opening/closing member and a controller configured to perform an abnormality determination process and a masking process. The abnormality determination process determines occurrence of a foreign object being entrapped or caught by comparing driving information corresponding to a driving status of the motor to a predetermined threshold value. The masking process invalidates the abnormality determination process over a predetermined masking period when the motor is activated. The controller includes a correction unit. The correction unit corrects at least one of the masking period or the threshold value when the motor is activated in a direction opposite to that of a preceding operation in a state in which the opening/closing member is in a high-load range.

According to an aspect of the present invention, an electric working machine is provided. The electric working machine comprises a motor, an operation portion, a working portion, and a controller. The working portion is configured to be driven by the motor and act on a work target. The operation portion is configured to be operated by an operator. The controller is configured to control a maximum power that can be input to the motor to a first power when receiving an operation signal indicating an amount of operation to the operation portion. Further, the controller is configured to perform first switching control to switch the maximum power to a second power that is less than the first power when rotation speed of the motor becomes less than a first threshold due to a load on the working portion.

Provided is a brake apparatus, a brake control method, and a method for determining a lock abnormality in a motor capable of reducing motor drive noise at the time of a self-diagnosis of the motor regardless of a condition. A brake control method includes issuing a drive instruction to repeat ON/OFF driving a plurality of times and drive a motor in such a manner that a rotational frequency of the motor during an OFF time period does not fall to zero and a peak of the rotational frequency of the motor during an ON time period increases as the ON/OFF driving is repeated, carrying out terminal voltage detection to detect a terminal voltage of the motor at the time of the ON/OFF driving carried out by the issuing of the drive instruction, and determining a lock abnormality in the motor to determine whether there is the lock abnormality in the motor based on a characteristic of the terminal voltage during the OFF time period of the ON/OFF driving that is detected by the carrying out of the terminal voltage detection.

A power tool is provided including a power supply interface having a first node and a second node, a power switch circuit, an input unit actuatable by a user, a controller configured to control the power switch circuit to regulate the supply of electric power, and a driver circuit disposed between the controller and the power switch circuit configured to receive control signals from the controller and drive the power switch circuit according. A no-volt prevention circuit is configured to enable a supply of power to at least one of the driver circuit or the controller when the input unit is actuated after the power supply interface is coupled to the power supply, but not when the input unit is actuated before to the power supply interface is coupled to the power supply.

A power tool including a power supply interface, a motor control circuit configured to regulate supply of power from the power supply interface to a motor, and an input unit actuatable by a user. A no-volt prevention circuit receives a first voltage signal from the power supply interface and a second voltage signal from the input unit. The no-volt protection circuit includes a main semiconductor switch arranged on a current path from the power supply interface to at least one component of the motor control circuit, and a resistor-capacitor circuit to turn the main semiconductor switch ON when the input unit is actuated after the power supply interface is coupled to the power supply, but not when the input unit is actuated before to the power supply interface is coupled to the power supply.