Impact tools and control modes

An impact power tool comprising:

• a housing;
• a brushless motor received in the housing;
• a power switch coupled to the housing and actuatable by a user;
• an output spindle;
• an impact mechanism configured to be driven by the motor and to rotationally drive the output spindle, the impact mechanism configured to selectively apply rotational impacts to the output spindle when a torque on the output spindle exceeds a torque threshold;
• and
• a controller configured to control power delivery to the motor in response to actuation of the power switch,
• wherein the controller is configured to selectively cause the motor to operate in a first mode for installing a fastener or in a second mode for removing a fastener, and
• wherein, when the motor operates in the first mode, the controller is configured to control the motor with a first conduction band value and a first advance angle value during a first time period until a first parameter is reached, and to control the motor with a second conduction band value and a second advance angle value, at least one of which is greater than the first conduction band value and the first advance angle value, after the first time period.

An impact power tool comprising:

• a housing;
• a brushless motor received in the housing;
• a power switch coupled to the housing and actuatable by a user;
• an output spindle;
• an impact mechanism configured to be driven by the motor and to rotationally drive the output spindle, the impact mechanism configured to selectively apply rotational impacts to the output spindle when a torque on the output spindle exceeds a torque threshold;
• and
• a controller configured to control power delivery to the motor in response to actuation of the power switch,
• wherein the controller is configured to selectively cause the motor to operate in a first mode for installing a fastener or in a second mode for removing a fastener, and
• wherein, when the motor operates in the second mode, the controller is configured to control the motor with a first conduction band value and a first advance angle value during a first time period until a first parameter is reached, and to control the motor with a second conduction band value and a second advance angle value, at least one of which is less than the first conduction band value and the first advance angle value, after the first time period.