Abstract: A power tool includes a motor, a speed sensor configured to sense a speed of the motor, and a controller connected to the motor and the speed sensor. The controller is configured to provide power to the motor, determine a first command based on the speed of the motor, determine, while in a first operating mode, whether the first command is greater than or equal to a first limit, determine, while in the first operating mode, a PWM duty cycle ratio based on the first limit, determine, while in a second operating mode, whether a parameter command is greater than or equal to a parameter limit, while in the second operating mode and when the parameter command is greater than or equal to the parameter limit, the PWM duty cycle ratio based on the parameter limit, and drive the motor based on the PWM duty cycle ratio.

Abstract: A representative fault-tolerant rotating electromechanical actuator comprises a permanent magnet synchronous motor with first and second windings that each comprise three phases. First and second voltage source inverters (VSI) provide output signals independently with respect to each other. The first VSI provides output signals to drive the three phases of the first winding, and the second VSI provides output signals to drive the three phases of the second winding. The three phases of the first winding are driven simultaneously with the three phases of the second winding. Control electronics monitor signals associated with the three phases of the windings and detect a fault condition within a first phase of the first winding. The control electronics command the first VSI to drive only second and third phases of the first winding while simultaneously commanding the second VSI to drive the three phases of the second winding.

Abstract: A power tool that includes a brushless motor, a power switching circuit, a current sensor, and an electronic controller. The power switching circuit provides a supply of power to the brushless motor. The current sensor is configured to sense a current of the brushless motor. The electronic controller is configured to receive a first signal indicative of current of the brushless motor, generate a current command, set a conduction angle of the brushless motor based on the current command, supply a PWM signal having a duty cycle to the brushless motor to increase current of the brushless motor, determine whether duty cycle equals a first threshold, maintain the duty cycle at the first threshold, modify the conduction angle to increase the current of the brushless DC motor, determine whether current equals a second threshold, and control the second conduction angle to maintain current at the second threshold.

Abstract: Systems and methods for implementing an electronic clutch in a powered fastener driver. One fastener driver includes a motor, a trigger, a position sensor, a speed sensor, and a controller. The position sensor is configured to sense a position of the lifting assembly. The speed sensor is configured to sense a speed of the motor. The controller is configured to provide power to the motor. The controller is configured to receive speed signals from the speed sensor indicative of the speed of the motor, and determine whether the speed of the motor has dropped by a speed drop threshold within a first period of time. The controller is configured to activate an electronic clutch to electronically brake the motor for a second period of time. In response to the second period of time having passed, the controller is configured to provide power to the motor.

Abstract: Systems and methods for electronically limiting torque in a power tool. One power tool includes a motor, a trigger, and a controller connected to the trigger and the motor. The controller is configured to provide, in response to actuation of the trigger, power to the motor, determine a speed of the motor, activate the electronic clutch, in response to determining that the speed of the motor has dropped by the speed drop threshold within the first period of time, to electronically brake the motor for a second period of time, and provide, in response to the second period of time having passed, power to the motor.

Abstract: A representative fault-tolerant rotating electromechanical actuator comprises a permanent magnet synchronous motor with first and second windings that each comprise three phases. First and second voltage source inverters (VSI) provide output signals independently with respect to each other. The first VSI provides output signals to drive the three phases of the first winding, and the second VSI provides output signals to drive the three phases of the second winding. The three phases of the first winding are driven simultaneously with the three phases of the second winding. Control electronics monitor signals associated with the three phases of the windings and detect a fault condition within a first phase of the first winding. The control electronics command the first VSI to drive only second and third phases of the first winding while simultaneously commanding the second VSI to drive the three phases of the second winding.