US Patent 10265758 Power tool

A power tool including a moveable piston, a motor capable of driving the moveable piston to perform work on a work piece, and a distance sensor configured to sense a movement of the moveable piston. The distance sensor operable to provide sensor information indicative of the movement of the piston. A controller receives the sensor information from the distance sensor. The controller operates the motor to perform work on the work piece based in part on the sensor information that the controller receives from the distance sensor.