Abstract: A spindle of a machine tool driven by an induction motor is controlled by a torque control system including a pulse generator coupled to the spindle, a reversible counter which counts the number of pulses, a first register connected to receive an output signal of the counter via sampling gate. The data in the first register is transferred to a second register and difference between data in the first and second registers is calculated by a calculator in the form of a register. An input device delivers a speed instruction signal and an angular position instruction signal which is added to an output signal of the first register to form a position instruction signal. A computation unit is provided to calculate respective phase currents of the induction motor in response to the speed instruction signal or the position error signal for continuously controlling motor torque or position the spindle at an instructed angular position.