Abstract: A star wheel, typically the starter gear of an internal combustion engine is magnetically coupled to a stationary pickup, for example a coil-core or yoke combination, a Hall generator, or the like. Upon rotation of the gear, or star wheel, sequential signals will be induced in the pickup which, related to time, provide an output signal representative of speed. To determine an angular reference position, an additional magnetically responsive reference element is included in the magnetic circuit formed by the stationary pickup and the teeth of the star wheel, to additionally modify the reluctance of the pickup-star wheel magnetic circuit, and change the characteristic of the output signal, for example by a phase jump, a discrete output level jump, or the like. The reference element may be a pin of soft iron, or of the material having soft iron characteristics, a pre-magnetized pin, or the like, exposed to the yoke arms of a pickup surrounding the star wheel, or otherwise magnetically coupled to the pickup.

Abstract: A wheel velocity sensor of the type having a toothed rotor and a stator with a detecting head mounted adjacent the rotor in proximity with the rotor teeth. The rotor is assembled with the bearing seal in the wheel hub as an integrated unit, being encased within a cavity formed in the seal to receive the rotor. The detecting head of the stator contacts the face of the seal, which is coated with a low friction material, so that a constant gap is maintained between the detecting head and rotor during rotation of the wheel to obtain more accurate wheel velocity signals.

Abstract: Disclosed in a differential operational amplifier for use with a proximity type pick up. It has a common mode rejection input circuit comprising a diode and transistor connected to each input as well as diodes connected across the amplifier differential inputs. Common mode signals are clamped at the input to both protect the amplifier and prevent false transitions at the output.

Abstract: A D.C. motor comprises a permanent-magnet stator including a flux-return structure and at least one permanent-magnet stator magnet mounted on the flux-return structure and also an armature mounted for rotation within the stator and having a circumferential succession of armature teeth. The rotary speed of the armature during operation of the D.C. motor is ascertained indirectly by sensing the variations in the stray flux of the motor at the exterior of the flux-return structure.

Abstract: A pulse generator for the generation of pulses which are synchronously associated with the movement of a mechanical part comprises a toothed element, the teeth of which run past a pick-up head, the pick-up head comprising a first winding fed by a carrier frequency, which produces a field which is modulated by the teeth of the element and a second winding in which a voltage is induced by the modulated field, the induced voltage is supplied to a phase discriminator which produces a pulse sequence having a keying ratio proportional to the relative phase position of the induced voltage and the carrier frequency and the pulse sequence is fed to an integration element which produces a voltage signal proportional to the keying ratio.

Abstract: The position or presence of a metallic object is detected by an electronic circuit which senses a shift in phase between a first cyclic signal and a second cyclic signal which shifts in phase in response to movement of the object. An oscillator produces the first cyclic signal which is used as the reference signal and as the excitation for a parallel resonant circuit which produces the second signal. The phase of the second signal is shifted in response to movement of a metal plate or a shorted coil in an electromagnetic field produced by an inductor in the resonant circuit. The degree of the phase shifts may be used to detect the position of an object in the electromagnetic field or rate of the phase shifts may be used to detect the velocity of an object. An exclusive-or gate senses the changes or differences in phase between the two cyclic signals and produces an output signal representative of the changes or differences in phase.

Abstract: An exciter for use with a shaft speed magnetic pickup includes a strip of flexible, stretchable, sheet material having a plurality of magnetic elements attached to it that are uniformly spaced along the strip, enabling the magnetic elements to be attached to the exterior of various diameter rotatable shafts by stretching and fastening the strip about the circumference of the shaft close to the magnetic pickup which generates an electrical pulse signal whenever a magnetic element passes by it. The pulse signal is processed to produce a readout of shaft speed. Two magnetic pickups circumferentially spaced about the shaft closer than the circumferential spacing of the magnetic elements are used to provide signals that can be processed to indicate shaft direction of rotation as well as shaft speed.

Abstract: In a position control device for driving a speed controlled motor, the motor having coupled thereto a tachometer generator for providing velocity feedback, a brushless tachometer generator having at least one position transmitter for the rotor thereof is used as the tachometer generator and the position signals of the position transmitter also used to provide an actual value feedback for the position control.

Abstract: A velocity sensor for sensing the speed of a moving conductive body employing an E-shaped magnetic core having a pair of spaced Hall effect devices positioned on the end of the central core, the ends of all cores being arranged adjacent to the path of the moving conductive body. The difference in output voltage registered by the two Hall effect devices is indicative of the speed of the conductive body.

Abstract: A speed sensor mounting assembly for a gas turbine speed sensor insures a magnetic speed sensing device is positioned a predetermined distance from a toothed wheel mounted on the output shaft of the gas turbine. The magnetic speed sensing device, which may be of conventional manufacture, is affixed in a fitting located at one end of a flexible conduit which extends outwardly from the vicinity of the shaft to an access port in the engine casing. The use of the flexible conduit allows remote rotation of the fitting and sensing device to threadably engage the fitting with a socket affixed to the engine adjacent the output shaft. Electrical conductor leads are contained in the flexible conduit for interconnection of the sensing device and appropriate electronic circuitry.

Abstract: Indications of speed of an internal combustion engine are derived from an engine member connected to and rotating directly with the crankshaft, such as the teeth on the fly-wheel, so as to provide indications for speed measurements on a sub-cycle basis (that is, many times during each revolution). Sensing of an integral number of subsequent indicia, such as teeth, starts and stops an interval counter, such as a clock, having a frequency much greater than the frequency of indicia sensed, feeding a counter; for each integral number of indicia, the counter provides a manifestation of the time lapse between the indicia, and therefore the time to rotate through the small angular increment of the indicia spacing. The ratio of the integral number, which may be one or many, to the total number, times the ratio of the counter accumulation to the clock frequency, provides a measure of speed in speed dimensions of revolution per unit of time.

Abstract: A detector for a dynamic phenomenon with a cyclically varying condition, as motion of a rotating part. At least three digital sensors are separated in phase with respect to the cyclic condition. The instantaneous outputs of the sensors have a plurality of repeating sequential states so long as the dynamic phenomenon exists. The instantaneous outputs of the sensors have at least one state which does not occur during existence of the dynamic phenomenon but which does occur in the absence thereof. Logic circuits respond to the digital sensor outputs and detect information about the dynamic phenomenon. Detection of the repetition rate of an instantaneous output state of the sensors provides a measure of speed. An absence of rotation is indicated by the occurrence of another output state. In another disclosed embodiment, the detector monitors a three phase power system and detects a phase outage by the occurrence of an abnormal sensor output state.

Abstract: A speed measurement system for converting signal pulses directly into a 13 bit binary number for input to a digital processor is disclosed. The signal pulses are generated as a function of incremental shaft rotation. A plurality of additional pulses are injected in the pulse train between successive displacement or signal pulses, such that a stream of equally spaced pulses is produced at a predetermined speed. The number of generated displacement and injected pulses are counted during predetermined time intervals for providing a direct speed measurement.

Abstract: A speed sensor for an adaptive braking system is disclosed. The sensor is enclosed in a housing, so that all critical adjustments may be made at the time the sensor is manufactured and not when the sensor is installed on the vehicle. The entire sensor package is small enough to be mounted within the tubular axle used on many relatively large vehicles, such as semi-trailers, which are in use today. A driving connection is provided between the speed sensor and the hub cap of the vehicle, which of course, rotates with the corresponding vehicle wheel.

Abstract: A rotation sensor and output signal processing apparatus is presented. The rotation sensor is a ring core flux gate magnetometer whose output varies as a function of the earth's magnetic field. The phase angle of the second harmonic of the magnetometer output is sensed to provide an indication of the state of rotation of the magnetometer. When a state of no rotation is sensed, actuating signals are delivered to a control system to sense borehole parameters and telemeter the parameters to the top of the borehole.

Abstract: 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.

Abstract: A speed detector for use with a miniature DC motor is disclosed wherein a device such as coils or Hall generators for detecting the magnitude and direction of leakage flux are placed in opposed relationship with at least one pair of field poles of the DC motor, so that an output signal having a frequency proportional to an integral multiple of the number of slots of the armature may be derived.

Abstract: A rotation indication system having an improved sensing device for determining the velocity of a rotating body is disclosed. The improved sensing device is tubular in configuration and includes a source of magnetic flux and two pole pieces that define a split magnetic field. The sensing device is mounted in close proximity to a rotor which is connected to the rotating body. The rotor has apertures which interrupt the split magnetic field producing an output signal with a frequency proportional to the velocity of the rotating body. The sensing device is oriented relative to the rotor apertures so that each pole piece is alternatively in register with an aperture to produce the desired output signal. Since the sensing device is tubular in shape, it can be rotated about its axis to obtain the desired orientation with the rotor apertures, thus permitting the use of the sensing device with a wide range of rotor diameters having various aperture spacings.

Abstract: An E-shaped magnetic core with a sensing coil wound around each outer leg, these coils being connected in series and the center leg made of a magnet to establish a symmetrical magnetic field. When a conductive but non-magnetic material is passed through the flux field established in the air gap between the center and outer legs, eddy currents are induced in the material which oppose and momentarily change the magnetic field inducing a detectable voltage in the coils.