US 4,378,519 AGranted

Transducer system with increased tracking capability

AssigneeXerox Corporation

InventorWilbur E. DuVall

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Abstract

The number of data tracks or positions that a transducer can access or track is increased, beyond that conventionally permitted by the transducer conductor spacing, by first providing a plurality of signals corresponding in number to the factor by which the tracking capacity of the transducer is to be increased, with all signals having a common frequency equal to that of the drive signals applied to the transducer stator windings and with each signal being phase delayed relative to the other signals by one or more clock increments, then accessing the signal having a phase corresponding to the data track to be tracked, providing from that accessed signal a plurality of additional relatively phase delayed signals, and applying each of the later phase delayed signals to one of a plurality of phase detectors each of which also receives an input corresponding to the squared transducer rotor signal whereby the phase detectors provide at their output width modulated signals having a low frequency component corresponding to the rotary position signal.

Claims4

Dependent claims

A system for increasing the number of positions trackable by a transducer having relatively moveable windings beyond that permitted by the conductor spacing of the transducer windings, comprising:

first means for generating a clock signal;
second means connected to receive said clock signal for generating both a first signal having a phase determined by the relative motion of said relatively moveable windings and a phase reference signal;
third means connected to receive said clock signal and said phase reference signal for providing a plurality of signals each phase delayed relative to the other of said plurality of signals by one or more clock signal increments;
fourth means connected to receive said plurality of signals and control signals for outputting one of said plurality of signals, said one of said plurality of signals having a phase corresponding to the positioned to be tracked by the transducer;
phase detector means connected to receive said first signal and said one of said plurality of signals for providing a width modulated signal having a low frequency component corresponding to track position;
and
filter means for filtering out high frequency components of said width modulated signal to provide a signal indicative of track position.

4 more elements

Dependencies are inferred from the claim text.