Motor servo system with multiplier means to drive and servo the motor

Claim 1

A servo/drive system for introducing sinusoidal drive signals to the windings of a motor having at least two windings, comprising the combination of; tachometer means coupled to the motor for generating a tachometer signal indicative of the speed/phase characteristics and thus of the rotational error of the motor; speed/phase control servo means coupled to the tachometer means; means for providing a reference clock to the speed/phase control servo means, wherein the speed/phase control servo means generates the error signal by a comparison of the signal from the tachometer means and the reference clock; error signal/shaft angle multiplier means including at least two Hall element means integral with the motor and coupled to the speed/phase control servo means and to respective windings of the motor with no switching therebetween, the multiplier means being responsive to the angular position of the rotor to inherently generate within the multiplier means sinusoidal drive signals for each respective winding which are the product of the instantaneous rotational error of the motor times the instantaneous angular position of the motor shaft; means for continuously introducing the sinusoidal drive signals to each of respective motor windings simultaneously, and including amplifier means continuously coupled between the error signal/shaft angle multiplier means and each of the motor windings; and said sinusoidal drive signals having amplitudes proportional to the signals indicative of the rotational error, and phase proportional to the motor angular position, which drive signals provide both motor drive and servo control for the motor.