Patent ID: 10987784

Abstract:
An impact tool of the present disclosure provides an impact mechanism having a hammer and an anvil, the hammer being rotatable about a first axis and to periodically impact the anvil to drive rotation of the anvil about the first axis. The electric motor includes a plurality of pole pairs of windings and a rotor that is rotatable with respect to consecutively energized pole pairs of windings. No encoder or sensor is electronically coupled to the electric motor to detect a position of at least one magnet attached to the rotor with respect to at least one pole pair when the rotor is in a stopped condition. When the rotor is in the stopped condition, the motor controller energizes the at least one pole pair to initiate rotation and detect a back EMF generated by movement of the rotor without a sensor or encoder to indicate the predetermined location of the at least one magnet attached to the rotor with respect to the at least one pole pair.