Abstract: In a motorcycle, to prevent an increase in the diameter of a hub in association with the mounting of a pulser ring and for increasing the flexibility when arranging a wheel speed sensor. An annular groove is formed on a side surface of an annular rear brake disk in an annular shape. A stepped annular pulser ring is mounted to the side surface of the rear brake disk so that a pulser section is located in the groove. Thus, a space for accommodating the pulser ring on an inner periphery of the rear brake disk is eliminated. In addition, the size of a hub-engagement hole on the rear brake disk may be reduced. Since the pulser section of the pulser ring is located in the groove of the rear brake disk, it does not take much space in the direction of an axle.

Abstract: Methods and systems are described for a system for obtaining information regarding a flow. These methods and systems comprise a signal generator configured to generate an alternating current signal at a carrier frequency and a transformer arranged to receive the generated signal, wherein the transformer and carrier frequency are selected so that the generated signal resonates at the carrier frequency. The alternating signal is then used to cause plasma to form across a gap between two electrodes, wherein the voltage drop across the gap is directly proportional to the flow's velocity. This voltage may then be measured to determine the flow velocity.

Abstract: A method and a device for measuring the speed of a pulse-activated electric motor are described. According to this method, the motor is fully activated at time intervals to be determined for a defined measuring time by the circuit element provided for timing and, in this time, the frequency of the current ripples, which is proportional to the motor speed, is measured. A current-proportional voltage measuring device is located on the circuit element, on whose load side are located an amplifier, filters, and an evaluation circuit in the form of a comparator for determining the frequency of the current ripples flowing in a measured phase during which the motor is fully activated.

Abstract: A method of processing a pulse train output signal provided by a non-contact sensor that senses the rotational speed and angular position of a rotating wheel includes comparing the amplitudes of the pulses with a variable switching threshold value, and adjusting the value of the variable switching threshold value if the difference between the amplitudes of two successive pulses exceeds a maximum value.

Abstract: A sensor-equipped hub unit comprises a hub unit 1 having a wheel-side raceway member 4, a body-side raceway member 5, and two rows of rolling bodies 6, and a sensor device 2 provided on the hub unit 1. The sensor device 2 has a magnetostrictive sensor 31 for detecting a reverse magnetostrictive effect of the raceway member 4 produced by a force exerted thereon by the rolling bodies 6. The sensor device 2 detects rotation from the number of repetitions of a variation in strain and also detects the force acting on the wheel-side raceway member 4 from the amplitude of strain.

Abstract: A magnetic motion sensor has: two magnetic sensors aligned in a direction along which changes in a magnetic field shift for detecting an appearance of the changes; a differential means for taking out a differential signal of output signals from these two magnetic sensors; and a timing detection means for generating a pulse, indicating a timing at which the changes in a magnetic field pass through either of the magnetic sensors, when an output signal of the magnetic sensor in question strides over a threshold value, while generating a pulse, indicating a timing at which the changes in a magnetic field pass through in between the magnetic sensors, when the differential signal strides over the threshold value.

Abstract: A boat indicator enables a user to easily read engine speeds for boats which can switch between a low-speed trolling mode and a normal running mode at speeds higher than the trolling mode speed. The boat indicator includes an engine speed indicating section for indicating engine speed. The engine speed indicating section is adapted to switch between a normal mode display for indicating the engine speed over a relatively large range when the boat is in the normal mode and a trolling mode display for indicating engine speed over a relatively small, low-speed range when the boat is in the trolling mode. The normal mode display indicates engine speed detected with a first resolution over the large range. The trolling mode display indicates engine speed detected with a second resolution finer than the first resolution over the smaller range.

Abstract: An electronic driver and method for producing an output waveform for use by a tachometer comprises an input line that is connected in series with at least one ignition coil. The at least one ignition coil is driven during at least one current dwell period per an ignition cycle. A signal representative of at least one spark is caused to be generated on the input line by the at least one ignition coil during the at least one current dwell period of the ignition cycle. A controller is coupled to the input line. The controller discriminates between single and multiple sparks over consecutive ignition cycles. The signal is representative of at least one spark received on the input line from the at least one ignition coil. The controller responsively forms an output waveform having substantially equally spaced pulses aligned with the first spark and the output waveform corresponds to the ignition cycle received on the input line.

Abstract: A magnetic rotation detector includes a magnetic rotor having magnetic bodies, a detecting body that detects a change in magnetic flux that is caused by the magnetic bodies as the magnetic rotor rotates; and an abnormality determination portion that monitors an apparent fluctuation in rotational speed of the magnetic rotor based on a result detected by the detecting body and that determines that the magnetic rotor is in an abnormal state if the fluctuation occurs at a specific position of the magnetic rotor. The abnormality determination portion detects the occurrence of the fluctuation at the specific position of the magnetic rotor by making a determination on a distance between apparent positions of the magnetic bodies which correspond to the apparent fluctuation in rotational speed and calculates the distance on the basis of a product of an interval of generation of noise in an output signal detected by the detecting body and a rotational speed of the magnetic rotor at the time of generation of noise.

Abstract: A magnetic detection apparatus can be improved in its product yield. The magnetic detection apparatus includes a resin compact having a the magnet arranged in opposition to an object to be detected for generating a magnetic field, an IC chip with a magnetic detection part built therein for detecting a change in the magnetic field in accordance with movement of the object to be detected, and an IC package in which a lead frame having the IC chip installed thereon is sealed with a resin. A method for manufacturing such a magnetic detection apparatus includes a signal adjustment step for adjusting a signal generated from the magnetic detection part in a state in which the magnetic field is applied to the magnetic detection part to correct a deviation of the signal of the magnetic detection part generated in accordance with a relative displacement between the magnetic detection part and the magnet.

Abstract: A method and apparatus for determining the velocity of a rotating device is described herein. The apparatus includes a magnet assembly affixed to a rotating shaft of a rotating device and a circuit assembly. The circuit assembly includes a circuit interconnection having a sense coil and sensors affixed thereto. The circuit assembly is adapted to be in proximity to the magnet assembly, wherein the magnet assembly combines with the circuit assembly to form an air core electric machine such that voltages generated from the sense coil exhibits an amplitude proportional to the velocity.

Abstract: An airbag deployment rate sensor has a printed circuit board with a substrate that has guide slots for the withdrawal of deployable tapes. Each tape is fastened to the interior of the airbag. When the airbag is deployed, the tapes are withdrawn from tape cartridges mounted with respect to the substrate. The surfaces of the guide slot are coated with an electrically conductive coating. Static charges on the tapes are dissipated as they pass through the guide slots.

Abstract: A passive coupling structure constructed using printed circuit board traces is used to separate the low and high frequency components of an incoming digital signal. The low and high frequency components of the signal are sent to separate receivers on an integrated circuit. The low frequency receiver may be a conventional level based receiver. The high frequency receiver is a Schmitt-trigger with hysteresis around a DC level or two comparators with separate reference voltages. The outputs of these receivers are combined to produce a receiver output that has increased reliability and noise immunity.

Abstract: An object of this invention is to obtain a control apparatus capable of easily and speedily setting an output frequency, and it is constructed so as to change a change width of a frequency setting value in response to a rotational speed of a handle operation by an operator using a manual pulse generator for manually rotating a handle to generate a command pulse.

Abstract: A non-contact rotation speed and torque sensing device which uses the natural inhomogeneities in the magnetic properties of a rotating element (4) to measure movement, displacement and deformation of the rotating element. An alternating magnetic field is applied in the region of a rotating element (4) and a signal representing the change in magnetic flux caused by the inhomogeneities of the magnetic structure of the object is received at a sensor (1). By processing the sensed signal using the auto-correlation function, the speed of rotation of the element (4) may be determined through inspection of the periodicity of the signal.

Abstract: A method is described for determining a rotation speed and a rotation direction of a component (2), in particular a transmission output shaft, with a sensor device (1). In the sensor device (1), as a function of a rotation speed and direction of the component (2), a first sensor signal and a second sensor signal are generated, which are phase shifted relative to one another and each of which, on reaching an upper switching threshold or a lower switching threshold in the sensor device (1), triggers a switching signal. When there are alternating, consecutive switching signals of the two sensor signals, the sensor device (1) emits a pulse signal as a function of which a variation of a sensor signal is generated, which is used to determine a rotation speed of the component (2).

Abstract: To detect the rotational speed and angular position of a rotating wheel, a non-contact sensor (e.g., an optical sensor or a Hall sensor) scans scan marks on the wheel, and generates a pulse train. The amplitude of the pulses is compared in a comparator with a variable switching threshold. To achieve accurate measurement results, and to compensate for offset and long-term drift of the sensor, the switching threshold is adjusted if one or more of the following conditions is met: (i) the difference between the pulse amplitude and the switching threshold exceeds a fixable first maximum, (ii) the difference of the amplitudes of two successive pulses exceeds a fixable second maximum, (iii) the difference of the frequencies of successive pulses exceeds a fixable third maximum.

Abstract: A tachometer system is provided for a motor vehicle having an engine selected from a plurality of engines having unique maximum rated engine RPMs. The system has an RPM data signal and scale correction data. A microcontroller receives the RPM data signal and said scale correction data and generates a scaled tachometer signal therefrom in accordance with a computer program stored in a memory. A gauge drive circuit receives the scaled tachometer signal from the microcontroller. A tachometer gauge has a pointer driven by the gauge driver circuit. The computer program calculates the scaled tachometer signal according to a first scaling constant while the RPM data signal represents less than a predetermined RPM, and calculates the scaled tachometer signal according to a second scaling constant while the RPM data signal represents greater than the predetermined RPM. The second scaling constant is selected from a set of predetermined scaling constants according to the scale correction data.

Abstract: A magnet mounting structure for fastening a magnet to a spoke of a two-wheeled vehicle even without tool includes a knob member having a screw and the magnet and an internal thread member in which the screw is screwed. The spoke is held between the knob member and the internal thread member to allow the magnet to be fastened to the spoke.

Abstract: An apparatus and method for measuring a characteristic, such as speed, of a machine. A variable reluctance sensor (VRS) is coupled to a resistive element, which filters a portion of a basic output signal generated by the VRS having a frequency above a prescribed threshold level, thus removing high-frequency noise from the basic output signal. An amplifier amplifies the filtered output signal. The filtered, amplified output signal has an increased signal-to-noise ratio such that the machine characteristic, i.e. speed, can be more accurately measured during a slow speed operation. A controller generates a control signal received by a switching device to decouple the resistive element when machine speed exceeds a prescribed threshold level. Then, the basic output signal is used to measure the characteristic of the machine during normal machine operation.

Abstract: An airbag deployment sensor has a cartridge containing a quantity of tape one end of which is attached to the inside surface of an airbag cushion. Deployment of the cushion pulls tape from the cartridge at a rate that is monitored by transmitting light through the tape, or by detecting the presence of metalized, or magnetic shielding portions, of the tape.

Abstract: The method for correction of evaluation of a switching threshold of a magnetic sensor arrangement includes evaluating switching edges of a transmitter signal produced by a moving transmitter element and generating a signal output when the switching edges exceed or fall below a default threshold value. Individual threshold values are determined for each switching edge during the course of a measurement cycle to correct the default threshold value. This occurs by determining respective maximum and minimum values for each switching edge and then averaging them to obtain an average value for each switching edge. Then the average values are stored in a non-volatile memory as individual threshold values for subsequent correction.

Abstract: The rotational position of a shaft (10) with respect to a sleeve (12) is determined by using a sensor (14) rotating with the shaft (10) to detect an earth vector such as magnetic or gravitational field, using a coil (18) on the shaft in conjunction with a plurality of ferromagnetic elements (16) on the sleeve to monitor relative rotation, and calculating the rotational position from these parameters. Applicable to downhole use, particularly gamma ray measurements.

Abstract: An improved target wheel is provided for a bearing speed sensor. The target wheel includes an annular base which is sized to be press fit on a seat or extension of the inner race of a bearing. The base includes a first end and a second end. A plurality of encoding elements, in the form of spaced apart teeth, operatively extend from the first end of the base. The base is bent upwardly near the second end to form a portion which extends out of the plane of the base. This portion defines an angle of less than 90° with the plane of the base, and preferably forms an angle of about 30° to about 40°.

Abstract: A method for determining the position of an element driven along a travel segment by a shaft of a motor includes counting current ripples detected in an armature current signal of the motor as the motor shaft rotates to drive the element. A first time interval between when the motor is turned on with power being supplied to the motor and when the first current ripple is detected is determined. A second time interval between when the last current ripple is detected after the motor has been turned off with the power supplied to the motor being interrupted and when the motor shaft stops rotating is determined. First and second current ripple components corresponding to the first and time intervals, respectively, are estimated. The position of the element along the travel segment is determined based on the counted current ripples and the estimated first and second current ripple components.

Abstract: An airbag deployment sensor has a cartridge containing a quantity of tape one end of which is attached to the inside surface of an airbag cushion. Deployment of the cushion pulls tape from the cartridge at a rate that is monitored by transmitting light through the tape, or by detecting the presence of metalized, or magnetic shielding portions, of the tape.

Abstract: An airbag deployment sensor has a cartridge containing a quantity of tape one end of which is attached to the inside surface of an airbag cushion. Deployment of the cushion pulls tape from the cartridge at a rate that is monitored by transmitting light through the tape, or by detecting the presence of metalized, or magnetic shielding portions, of the tape.

Abstract: An airbag deployment sensor has a cartridge containing a quantity of tape one end of which is attached to the inside surface of an airbag cushion. Deployment of the cushion pulls tape from the cartridge at a rate that is monitored by transmitting light through the tape, or by detecting the presence of metalized, or magnetic shielding portions, of the tape.

Abstract: A rotation detecting device includes a rotating direction determining means for determining a rotating direction of the rotor based on a first signal and a second signal, generating a rotating direction signal based on the first signal and the second signal, and outputting a rotating direction determining signal by switching the rotating direction signal with an external switching signal, wherein the pulse signal generating means generates the pulse signal in response to the rotating direction determining signal.

Abstract: An analytical circuit for an inductive electromagnetic sensor with external excitation (1) generates an output signal which is transformed to give an output signal (out), by means of transformation to a reference voltage (Vref) in an inverting low-pass filter (12), which has no hysteresis delay and is free from multiple triggering. By comparison of the reference voltage with three voltage thresholds in a diagnostic circuit (6), line interruptions and short-circuits are recognised by battery voltage or reference voltage potentials.

Abstract: The present invention relates to a device for converting vehicle speed signals characterized in that it includes a controller for converting vehicle speed signals which has a switch for controlling vehicle speed signals connected thereto and is mounted between a vehicle speed sensor and an electronic speedometer or tachometer. According to the present invention, it is possible to enhance the accuracy of measurement of vehicle speed, and to save separate costs for development of speed gear sets and simplify necessary specifications of a transmission.

Abstract: A method is described for determining a rotation speed and a rotation direction of a component (2), in particular a transmission output shaft, with a sensor device (1). In the sensor device (1), as a function of a rotation speed and direction of the component (2), a first sensor signal and a second sensor signal are generated, which are phase shifted relative to one another and each of which, on reaching an upper switching threshold or a lower switching threshold in the sensor device (1), triggers a switching signal. When there are alternating, consecutive switching signals of the two sensor signals, the sensor device (1) emits a pulse signal as a function of which a variation of a sensor signal is generated, which is used to determine a rotation speed of the component (2).

Abstract: An electronic circuit measures a pulse frequency and/or a pulse period of pulses in a sensor signal originating in a sensor coil, the pulses being zero crossing pulses. The circuit includes a filter stage having an input connected to the sensor coil, the filter stage being for removing electrical noise from the sensor signal to provide a filtered sensor signal. The circuit also has a signal strength sensing circuit connected to receive at least one of the sensor signal and the filtered sensor signal, the signal strength sensing circuit producing a variable threshold signal, which is a substantially monotonically non-decreasing function of a strength of the sensor signal. A variable threshold zero crossing detector is connected to receive the filtered sensor signal and the variable threshold signal. The variable threshold zero crossing detector has an upper threshold to test for zero crossing in a positive direction and a lower threshold to test for zero crossing in a negative direction.

Abstract: A circuit for inputting and processing a signal from a speed sensor element, includes a comparator having first and second input terminals and first and second input circuits connected to receive the signal. The first input circuit is connected to a first input terminal of said comparator, and the second input circuit is connected to a reference voltage and to the second input terminal of said comparator. A switchable voltage divider circuit interruptibly connecting a voltage divider circuit for reducing an amplitude of the signal on said first input circuit; and a microprocessor is connected to receive and process an output of the comparator and to determine a speed value based thereon. The microprocessor controls switchable voltage divider based on the magnitude of determined vehicle speed.

Abstract: A system for improving the duty cycle output of a vehicle speed sensor circuit is disclosed. The vehicle speed sensor circuit can be configured, for example as a binary counter, to provide a particular number of pulses per distance of vehicle travel. An output of the vehicle speed sensor circuit is generally divided by placing varying values on particular load pins of an associated counter circuit, thereby providing a substantially improved duty cycle output from the vehicle speed sensor circuit, which is independent of an associated sensor duty cycle. The output of the vehicle speed sensor circuit can be divided utilizing a toggle flip-flop circuit integrated with the vehicle speed sensor circuit. The toggle flip-flop can be configured as an edge-triggered toggle flip-flop. The vehicle speed sensor can be utilized to sense rotating members present in a vehicle. The vehicle speed sensor thus provides a digital pulse output for every tooth that passes in front of the vehicle speed sensor.

Abstract: A method and a device for measuring the speed of a pulse-activated electric motor are described. According to this method, the motor is fully activated at time intervals to be determined for a defined measuring time by the circuit element provided for timing and, in this time, the frequency of the current ripples, which is proportional to the motor speed, is measured. A current-proportional voltage measuring device is located on the circuit element, on whose load side are located an amplifier, filters, and an evaluation circuit in the form of a comparator for determining the frequency of the current ripples flowing in a measured phase during which the motor is fully activated.

Abstract: Provided is rotational-state-of-wheel detecting apparatus that can avoid output of an incorrect rotational direction during a halt of a wheel. In ECU 10, a signal input section 10a accurately detects wheel speeds and rotational directions of respective wheels 12, 14, 16, 18, and, based on the results, respective computers 10b, 10c, 10d execute ABS control, TC control, and VSC control. On this occasion, switching of the rotational direction is restricted with a computation result of wheel speed of zero, and it is thus feasible to prevent occurrence of a malfunction or state hunting being repetitive switching of signs, due to an external magnetic field during halts of the wheels 12, 14, 16, 18. This further optimizes the state control of a vehicle.

Abstract: The present invention relates to an active magnetic field sensor, in particular a wheel bearing sensor unit, comprising at least one magnetic sensor element (10, 21, 36) for converting a temporally periodic magnetic field into a temporally periodic electric sensor signal at signal outputs (37, 31) and an electronic signal-evaluating circuit, the said magnetic field sensor being electrically fed by way of a sensor interface, wherein an active electric processing of periodic signals (38, 39) of the magnetic sensor element is performed in two or more separate signal channels of the evaluating circuit respectively associated with the sensor signals.

Abstract: A system for controlling the rotational speed of a fan, according to a reference clock having a reference frequency, is disclosed. The rotational speed corresponds to a fan rotational speed signal. The fan rotational speed controlling unit compares the reference clock with the fan rotational speed signal, to output a speed controlling signal. The Voltage generating circuit generates a level signal corresponding to the speed controlling signal. The driving unit generates a driving signal to control the rotational speed of the fan according to the level signal. When the fan is assembled with the controlling system, only coils with the same number of turns need to be use to obtain various rated rotational speeds of fans of different specifications by altering the reference frequency of the controlling system. Because coils with different number of turns are not required in stock at the same time, the time cost and the manufacturing cost can be reduced.

Abstract: A method for conditioning a coded signal including: determining a time constant, on the basis of which the data were coded, from the received signal and evaluating the received signal according to the determined time constant. A device for conditioning a received signal that transmits coded data has a determining device for determining a time constant, according to which the data were coded, from the received signal and an evaluation device for evaluating and processing the received signal according to the determined time constant.

Abstract: An apparatus and method for detecting gear features is provided. The apparatus includes a magnetic-sensing element, a thresholding module, and an output module. The magnetic-sensing element may provide a sensor-output signal indicative of the presence of a gear feature. The thresholding module may (i) transform the sensor-output signal into a characteristic waveform, which is also indicative of the presence of the gear feature; (ii) detect a first difference between the characteristic waveform and a reference signal, and responsively provide a tracking signal that tracks this difference; and (iii) detect a second difference between the tracking and reference signals, and responsively adjust the sensor-output signal. Adjustment may be performed (i) as a function of the second difference when it falls below a given threshold and (ii) by a predetermined amount when the second difference satisfies the given threshold.

Abstract: The present invention describes an active magnetic sensor, in particular for detecting the rotational behavior of a wheel, comprising a magneto-electric transducer (2) that is electrically connected to a modulator (5), a current source subassembly (4) controlling the signal current output at the sensor output (k3, k4), said sensor being characterized by an undervoltage monitoring circuit (10) which monitors the electric signal prevailing at sensor output (k3, k4) with respect to whether a voltage value falls below a first predetermined threshold voltage (VU) and which controls the signal current output at sensor output (k3, k4) in dependence on the result of this monitoring action by influencing the current source sub-assembly (4).

Abstract: A compensation circuit for compensating for switching point errors in rotating target or gear tooth sensors. The compensation circuit may include a processing unit and a persistent storage device, such as an electrically erasable programmable read-only memory (EEPROM), for storing compensation values that are used to provide automatic compensation of the rotating target sensor after the sensor module is installed by the end user. The actual and compensation values may be determined and stored as linear functions in the form of mX+b, where X is the frequency of the rotating target, m is the slope and b is the y-intercept. In order to provide compensation, the actual slope value m is multiplied by a compensation value. The y intercept (i.e. b) is selected, for example, to be the maximum speed in a given application. The compensation values (i.e.

Abstract: DC motor rotation speed alarm circuitry includes an input node, a connection node, a ground node, a comparison circuit and a signal generator. When the rotation speed of the DC motor changes during operation, floating voltage is generated between the driving circuit and the ground node. If the floating voltage is less than a preset voltage of the comparison circuit, the alarm signal outputted by the signal generator indicates that the DC motor is operating normally. If the floating voltage is greater than the preset voltage of the comparison circuit, the alarm signal outputted by the signal generator indicates that the DC motor is operating abnormally.

Abstract: A proximity detector includes an offset circuit for bringing at least one of a magnetic field signal and a tracking signal towards the other one of the magnetic field signal and the tracking signal when the detector output signal changes state. A magnetic field-to-voltage transducer provides the magnetic field signal indicative of an ambient magnetic field and a peak detector responsive to the magnetic field signal provides the tracking signal which substantially follows the magnetic field signal. A comparator generates the detector output signal which changes state when the magnetic field signal varies from the tracking signal by a predetermined amount.

Abstract: A sensor includes a Hall cell and a compensation circuit for subtracting a magnet background field from the Hall cell output to provide a signal corresponding to rotations of a toothed ferrous gear.

Abstract: A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential to single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor, converts the differential voltage to current, and variably attenuates the current. The rectifier and differential to single-ended conversion circuit converts the variably attenuated current to a voltage output. The input circuit includes an RC filter that attenuates high frequency signals. An initial threshold circuit generates an initial threshold voltage that compensates for internal resistance variations.

Abstract: The present invention discloses a position detecting apparatus that can adequately perform gain adjustment and offset adjustment and can suppress deterioration in position detection accuracy. The position detecting apparatus according to the present invention includes a position sensor outputting at least two phases of position detecting signals according to the movement of an object, and a signal adjusting unit performing the gain and offset adjustment of each position detecting signal by using adjustment data. In addition, the position detecting apparatus includes a counter that counts a wave number from a reference position, and a memory circuit that stores adjustment data corresponding to the wave number. Then, the signal adjusting unit adjusts gains and offsets of the position detecting signals on the basis of the adjustment data that corresponds to the counted wave number and is stored in the memory circuit.

Abstract: An electronic circuit measures a pulse frequency and/or a pulse period of pulses in a sensor signal originating in a sensor coil, the pulses being zero crossing pulses. The circuit includes a filter stage having an input connected to the sensor coil, the filter stage being for removing electrical noise from the sensor signal to provide a filtered sensor signal. The circuit also has a signal strength sensing circuit connected to receive at least one of the sensor signal and the filtered sensor signal, the signal strength sensing circuit producing a variable threshold signal, which is a substantially monotonically non-decreasing function of a strength of the sensor signal. A variable threshold zero crossing detector is connected to receive the filtered sensor signal and the variable threshold signal. The variable threshold zero crossing detector has an upper threshold to test for zero crossing in a positive direction and a lower threshold to test for zero crossing in a negative direction.

Abstract: A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential to single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor, converts the differential voltage to current, and variably attenuates the current. The rectifier and differential to single-ended conversion circuit converts the variably attenuated current to a voltage output. The input circuit includes an RC filter that attenuates high frequency signals. An initial threshold circuit generates an initial threshold voltage that compensates for internal resistance variations.