Milwaukee Electric Tool Corporation

Deere + Company

Shuvam Gupta

Alexander Huber

Long Wu

Gerry M Nagel

David Michael Loken

Sumit Dutta

Eric R Linn

Austin Gaspar

Gerald M Nagel

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.

Power tool including current-based field weakening

Systems and methods described herein provide for controlling a conduction angle applied to a motor, such as a power tool motor. Operations for controlling the conduction angle includes receiving by a motor controller, a desired speed signal, and monitoring a speed of the power tool motor. The operation further includes a motor controller determining an error value between the desired speed signal and the monitored speed and determining a conduction angle signal based on the error value. The operation also includes the motor controller determining whether the conduction angle signal is greater than the error value and increasing a conduction angle of the power tool motor in response to the conduction angle signal being determined to be greater than the error value.

Power tool including conduction angle control

Each one of the secondary converters has a corresponding transformer having a primary winding associated with a primary alternating current (AC) signal and a secondary winding associated with a secondary alternating current (AC) signal. A secondary controller provides secondary control signals to the secondary semiconductor switches of the secondary converters with one or more time-synchronized, target phase offsets with respect to an observed phase of the alternating current signal (e.g., primary alternating current signal or the secondary alternating current signal) to provide the target phase offset (or targeted phase offsets) commensurate with or sufficient to support a required electrical energy transfer from the primary controller to the corresponding secondary controller (or secondary controllers).

System for controlling a direct-current-to-direct-current converter to provide electrical energy to a vehicle implement

Growing community of inventors

Wauwatosa, WI, United States of America

Shuvam Gupta