Trw Limited

Jeffrey A Oicles

Morris Sorkin

Thomas F Martin

Disclosed is an apparatus for generating a pulse train whose instantaneous repetition rate represents the instantaneous angular velocity of a rotating device. An oscillator feeds a high frequency signal to a coil through which a center pole of magnetic material projects. The rotating device causes an object such as a gear to rotate, at least a portion of the extremity of which (e.g., the tips of its teeth, in the case of a gear) repeatedly comes into close contact with the tip of the center pole, separated only by a small air gap. This results in a change in inductance of the coil, which amplitude modulates the oscillator output. The modulated output is passed through a peak voltage detector which generates the desired pulse train.

Angular velocity indicating apparatus

A digital speedometer, frequency or event counter with digital display. The speedometer conventionally receives speed pulses representative of the speed of the vehicle. Due to the lack of synchronization between speed pulses and clock pulses the last display digit exhibits undesirable jitter. This may also be caused by backlash in the drive train or the like. This jitter is minimized by the provision of a precounter between the counter and the gate transfer to a storage register. This will permit transfer of the number generated in the counter only if the precounter is in the zero state, thus minimizing the jitter due to random occurrences of the last pulse.

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Glendale, AZ, United States of America

Jeffrey A Oicles