Abstract: A surgical tool system including a handpiece with a motor for driving a cutting accessory. The system includes a control unit for applying energization signals to the windings internal to the handpiece motor. At start-up and low speeds, the rotational position of the rotor relative to the static windings is determined based on inductances of the windings. At high speeds, the rotational position of the winding is determined based on the back electromotive forces developed across the windings.

Abstract: A surgical tool system including plural powered surgical handpieces. The handpieces are removably connected to a single control console. The control console has a power supply. A controller internal to the control console simultaneously supplies power to the plural handpieces. In the event the handpieces collectively draw more power than the power supply can provide, the control console temporarily stops the application of power to one of the handpieces.