Impact tools and control modes

An impact power tool comprising:

• a housing;
• a brushless motor received in the housing;
• a power switch configured to be actuated by a user;
• a controller operatively connected with the motor and configured to control power delivery to the motor in response to actuation of the power switch;
• an impact mechanism configured to be driven by the motor;
• and
• an output spindle configured to receive rotational impacts from the impact mechanism to rotate the output spindle,
• the impact mechanism configured to selectively apply the rotational impacts to the output spindle when a torque on the output spindle exceeds a threshold,
• wherein the controller is configured to control power delivered to the motor, during a first phase of operation, for a predetermined time period or until detection of one or more of the rotational impacts, the first phase of operation having one or more of a first non-zero target rotational speed, a first duty cycle setting, a first conduction band setting, or a first advance angle setting,
• wherein the controller is configured to control power delivered to the motor, during a second phase of operation after the first phase and starting upon expiration of the predetermined time period or detection of one or more of the rotational impacts, the second phase of operation having one or more of a second non-zero target rotational speed, a second duty cycle setting, a second conduction band setting, or a second advance angle setting, in order to achieve a motor power output during the second phase that is greater than a motor power output during the first phase, and
• wherein the controller is configured to control power delivered to the motor, during a third phase of operation after the second phase, upon detection of a reduction of a load on the output spindle, the third phase of operation having at least one of a third non-zero target rotational speed, a third duty cycle setting, a third conduction band setting, or a third advance angle setting, in order to achieve a motor power output during the third phase that is less than the motor power output during the second phase.