Patent ID: 11919135
Assignee: MILWAUKEE ELECTRIC TOOL CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC B  H | IPC B  H

Claim 0:
1. A power tool comprising:
a tool output;
a motor configured to drive the tool output;
a power switching network coupled between a battery pack interface and the motor;
and
a controller connected to the power switching network to control operation of the motor, the controller configured to:
operate the motor at a no-load speed at startup,
detect a load state of the power tool, the load state indicating whether the power tool is in a loaded state or an unloaded state,
determine a first indication of current on a current path between the battery pack interface and the motor and a second indication of current on the current path,
determine a difference between the first indication of current and the second indication of current,
determine whether the difference between the first indication of current and the second indication of current exceeds a predetermined divergence threshold,
determine that the power tool is in the loaded state when the difference between the first indication of current and the second indication of current exceeds the predetermined divergence threshold,
incrementally ramp up a speed of the motor from the no-load speed to a selected speed when the power tool is in the loaded state, and
incrementally ramp down the speed of the motor from the selected speed to the no-load speed when the power tool is in the unloaded state.