Sensorless thermal protection for power tools

Abstract

A power tool is provided, including a housing; a brushless DC (BLDC) motor arranged within the housing, the motor including a stator and a rotor rotatably disposed within the stator; a power module electrically disposed between the motor and a power supply, the power module including power switches; an actuator engageable by a user; and a control module configured to control a switching operation of the power switches to begin supply power to the motor when the actuator is engaged. The control module monitors engagement and disengagement events of the actuator, and ignores a subsequent engagement of the actuator if at least one of number of actuator engagement events and/or number of actuator disengagement events exceeds a predetermined threshold value within a predetermined time.

Dependencies are inferred from the claim text.