An electric impact tool in which a rotating mass rotates in a forward
direction to impact upon and transfer torque to an anvil, and rotates in
a reverse direction opposite the forward direction in response to such
impact. A direction sensor monitors the direction of rotation of the
rotating mass, and a controller turns an electric motor on and off during
respective forward and reverse rotation of the rotating mass. An energy
storing mechanism may be used to absorb energy from reverse rotation of
the rotating mass and release the absorbed energy to rotate the rotating
mass in the forward direction. A controller may be used to store the
angular position of the rotating mass upon each impact and turn off the
motor prior to the following impact to avoid energizing the motor during
stall.