Electro Corporation

Wilbur F Metcalf

A magnetic sensor for detecting the leading edge of a ferrous target as it passes the centerline of the sensor. The magnetic sensor includes a coil output representing the rate of change of magnetic flux as the target passes the sensor. The coil output is differentiated to provide a signal having a zero crossover point corresponding to the time at which the leading edge of the target passes the centerline of the sensor. The differentiated signal is applied to a zero crossover threshold detector to provide a first pulse, the trailing edge of which corresponds to the time at which the target's leading edge is coincident with the sensor centerline. Additional means provide a second pulse whose leading edge corresponds to the time at which the leading edge of the target is coincident with the centerline of the sensor.

Magnetic sensor and circuit for detecting the edge of a target as it

An event rate counter for measuring the number of events occurring per unit of time with an input pulse train having a fixed number of pulses per each occurrence of the event, wherein the input pulse train is scaled by a multiplier and divider to provide a direct readout in events-per-unit of time. The input pulse train is amplified and applied to a level detector, the output of which is a logic level pulse train having frequency equal to the frequency of the input signal. The pulse train frequency is monitored by a frequency detector for controlling a commutative switch. For low frequency pulse trains, the switch gates the pulse train from the level detector first to the multiplier, the output of which is gated by the switch to the divider. The multiply-divide sequence order is reversed by the switch for high frequency pulse trains thereby extending the dynamic frequency range of the counter.

Growing community of inventors

Sarasota, FL, United States of America

Wilbur F Metcalf