A diagnostic system for measuring acceleration of a piston of a reciprocating hammer is disclosed. The diagnostic system may include a magnet configured to induce, via electromagnetic induction and based on a movement of the piston, an electric current in a conductor. The diagnostic system may include a capacitor electrically coupled to the conductor and configured to store electric power based on the electric current induced by the magnet. The diagnostic system may include an accelerometer configured to measure an acceleration of the piston. The diagnostic system may include a communication device powered by the capacitor and configured to output a signal that identifies the acceleration measured by the accelerometer.

A rotary hammer includes a housing and a mode selection dial supported in the housing. The mode selection dial includes a cam. The housing supports a motor providing a rotational output. The housing supports a linkage moveable between a first position and a second position in response to engagement by the cam. A loss-of-control detection system measures acceleration of the housing and disables the motor upon the acceleration exceeding an acceleration threshold. The housing supports an operating mode detection system including a magnet and a Hall-effect sensor. The magnet is coupled to the linkage and moveable therewith between a third position corresponding to the first position of the linkage and a fourth position corresponding to the second position of the linkage. The Hall-effect sensor provides an output signal indictive of the position of the magnet. The loss-of-control detection system is selectively disabled based upon the output signal.

A power tool includes a housing, a motor supported by the housing, and a mode selector movable between a plurality of positions, each of the plurality of positions corresponding to one of plurality of operating modes of the power tool. The power tool further includes an operating mode detection system that detects a current operating mode of the power tool and generates an output signal corresponding to the current operating mode, and a loss-of-control detection system that performs protective operation based on an acceleration of the housing. The loss-of-control detection system is enabled or disabled based upon the output signal from the operating mode detection system.

A method of detecting positions of a striker for a rotary impact tool is provided. A first position of the striker can be determined before impacting an anvil of the rotary impact tool along an axial direction of the rotary impact tool. A second position of the striker can be determined after impacting the anvil along the axial direction. Operation of the rotary impact tool can be controlled based on the first position and the second position.