Patent ID: 11909345
Assignee: MILWAUKEE ELECTRIC TOOL CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  B | IPC B  H

Claim 10:
11. A power tool comprising:
a motor;
a power switching network coupled between a battery pack and the motor, wherein the power switching network includes a first power switching element and a second power switching element;
a braking circuit including one or more resistive loads and configured to be selectively coupled to motor terminals of the motor, wherein the braking circuit is configured to selectively couple the motor terminals to one selected from the group consisting of ground and a terminal of the battery pack; and
a controller connected to the power switching network and the braking circuit, the controller configured to:
determine a motor current of the motor,
select a regenerative braking threshold based on a current value that safely charges the battery pack during braking of the motor;
determine whether the motor current is below the regenerative braking threshold,
when the motor current is below the regenerative braking threshold:
control the power switching network to brake the motor,
enable the first power switching element to induce a freewheeling current to flow through the first power switching element, wherein the freewheeling current flows through a diode of the second power switching element, and

disable the first power switching element to provide the freewheeling current to the battery pack; and
control the braking circuit to brake the motor when the motor current is greater than or equal to the regenerative braking threshold.