摘要 |
A speed sensor for an electric motor having a permanent magnet stator and a wound rotor detects the variation in the electric field of the rotor due to commutation by means of induction in a coil placed in the electromagnetic field of the rotor, to produce an output signal indicative of the speed of rotation of the motor. Communication peaks in the ripple signal are amplified and converted into square pulses having a pre-determined duration. <IMAGE> |