Abstract: A system and method for determining the speed of a vehicle independent of angular wheel rotation rates is provided. The system generates time-varying signals corresponding to the vertical acceleration of the front and rear wheels. The front and rear wheel signals include corresponding perturbations caused by the wheels crossing road disturbances such as bumps. A time lag occurs between perturbations in the rear wheel signal and corresponding perturbations in the front wheel signal. An adaptive algorithm correlates the signals for various time delay values until a time delay value is determined which maximizes the correlation between the two signals. The calculated time delay value corresponds to the actual time lag between the front and rear wheels occurring before the rear wheels encounter a road disturbance previously encountered by the front wheels. Thus, the invention provides a determination of the actual speed of the vehicle determined independently from the angular rotation rates of the wheels.

Abstract: An object of this invention is to provide a position detecting apparatus which can accurately detect an angle of rotation of a rotary board mounted on a rotary shaft even if the former is not coaxial with the latter, or there is a play between the rotary shaft and its bearing. In a position detecting apparatus, a detecting transparent slit is formed in it in such a manner that the distance between the slit and the center of rotation of the rotary board changes with the angle of rotation .theta. of the rotary board, and a reference transparent slit having a predetermined radius is also formed in it. LEDs are arranged on one side of the rotary board, and PSDs are arranged on the other side of the rotary board in such a manner the formers are confronted through the transparent slits with the PSDs, respectively. The PSDs detect light beams passed through the transparent slits, to output light reception signals.

Abstract: A sensor (10) for determining angular velocity includes one or a plurality of piezoceramic plates (11, 12, 31 to 34), which are suitably oriented with respect to the axis of rotation and execute shear oscillations with the aid of an exciting circuit. If the sensor (10) is located in a rotating system, piezoelectric charges are generated on specific plate surfaces by generated Coriolis forces (K.sub.c). These charges represent a measure of the rotational velocity (.OMEGA.).

Abstract: A sensor for measuring the speed and/or position of a piston in relation to that of the cylinder it moves inside of in a dashpot of shock absorber for motor vehicles. The sensor consists of a permanent magnet (10) connected to the cylinder (1) and of a sensor winding (9) in the form of a cylindrical coil that operates in conjunction with the magnet. The sensor winding has leads at the ends. Additional leads for a shorter winding component (7 and 8) extend out separately upstream of the ends of the sensor winding.

Abstract: A vehicle speed measuring method and apparatus which can cope accurately with several vehicle speed sensors which produce different numbers of pulses for one rotation. Such vehicle speed sensors prepared for the method and apparatus produce predetermined different numbers of pulses for one rotation, some of such sensors defining a group wherein such numbers of pulses have a greatest common divisor greater than 1. It is first determined whether or not a particular vehicle speed sensor employed belongs to this group of sensors. When the sensor belongs to the group, pulses therefrom are frequency divided by a value obtained by division of the number of pulses produced for one rotation of the sensor by the greatest common divisor, and time data indicative of the time of appearance of a pulse by frequency division are stored into a memory for one rotation of the sensor.

Abstract: A projectile velocity measurement system for determining velocity of a lahed projectile in a launch tube in an underwater environment, the system comprising a transformer with secondary coils arranged in discrete groups with an increment of insulation shielding each of the groups of coils from the water therearound, the insulation increments being connectable to the projectile and being successively separable from the groups of secondary coils to expose such groups of coils successively to the water to short out such coils and reduce the voltage of the transformer secondary, and means for converting the speed of voltage reduction to the velocity of the projectile in the tube. In the case of launch of the projectile from a submarine, at least preprocessing of the voltage of the secondary is performed in the launch tube, and the preprocessed signal is passed to within the pressure hull of the submarine via a sealed electrical connector in the breechdoor of the launch tube to provide subsafe conditions.

Abstract: Disclosed herein is a malfunction detection apparatus for use in an outboard engine or motor system having a tachometer. The apparatus includes a tachometer output circuit for applying the tachometer signal to the tachometer in accordance with the input signal attributing to the battery voltage or engine speed, the battery abnormality detecting circuit for detecting the abnormal condition of the battery voltage, to provide the detection signal and the switch circuit for suspending, in response to the detection signal, the application of the tachometer signal from the tachometer output circuit to the tachometer. The apparatus is advantageous in that the erroneous operation of the tachometer can be positively prevented.

Abstract: A method for correcting the rotational speeds of vehicle wheels determined by wheel sensors, a measurement of wheel speeds of the wheels of a vehicle being carried out, with specific driving conditions being that the vehicle is being neither accelerated nor braked and has no transverse acceleration. In a first part of the method, a matching of the measured wheel speeds is carried out under the specific driving conditions when the condition that the vehicle speed is below a first threshold value is satisfied. The matching of the measured wheel speeds is carried out by determining a matching factor for each of the two vehicle sides, so that, for example for the left vehicle side, matched wheel speeds are obtained from the measured wheel speeds.

Abstract: A solid state speed indicator for railroad locomotives is provided with a plurality of indications in addition to speed. These include an acceleration indicator and an overspeed indicator. In addition, the speed indicator is provided with a dual range speed function having at least one particular use in drag operations. A variation of the solid state speed indicator is a retrofit design that replaces the meter movement in existing speed indicator equipment with a solid state display.

Abstract: A tachometer system for an internal combustion engine. The tachometer system uses one of two electromagnetic pulse sensing means to detect an electromagnetic signal produced by a firing of the engine. The sensing device may be an antenna or an inductive pickup. One of the signals is chosen and processed. A parameter indicative of pulse timing in the output signal is determined. This parameter is most advantageously a time between different ones of the output signals. The parameter is then converted into a value indicative of revolutions per unit time of the engine. The converting structure is advantageously formed by a personal computer.

Abstract: For measuring the rotational speed of a wheel in an antilocking protected vehicle brake system a rotational speed sensor is provided in which in accordance with the rotational speed of the wheel signals are electromagnetically induced which have an amplitude and frequency which increase regularly with the rotational speed. When due to error sources the amplitude of the induced signal does not increase with the frequency of the signal a rotational speed measured value is determined by means of the measured amplitude, i.e. not on the basis of the measured frequency. To avoid erroneous measuring signals it may likewise be provided that when the amplitude of the signal does not increase with its frequency the last measured value of the frequency of the induced signal at which the amplitude still increased with the frequency is used to determine the speed of rotation.

Abstract: A rotation sensing system includes a rotation sensor for outputting sinusoidal pulses, a waveform shaping circuit for shaping each of the sinusoidal pulses into a rectangular pulse, and a microcomputer for receiving an output of the waveform shaping circuit. In the microcomputer, the rectangular pulse appearing in the output of the waveform shaping circuit is processed so as to obtain information on the rotation of an object to be sensed, and also a malfunction of the rotation sensor is detected. Namely, when the rectangular pulse is not inputted into the microcomputer during a set time period, and at the same time when the level of the output of the waveform shaping circuit is equal to the level of the rectangular pulse, the microcomputer produces a signal representative of the malfunction of the rotation sensor.

Abstract: A tachometer particularly adapted for operation as a rotational velocity feedback transducer is provided. First and second proximity detectors are used to monitor orthogonal positions of an irregular surface portion of a rotating shaft and provide x and y signals that are substantially in quadrature. The x and y signals are differentiated with respect to time to provide differential signals that are representative of dx/dt and dy/dt, respectively. Signals representative of products x dy/dt and y dx/dt are generated from the x signal and the differential signal dy/dt, and the y signal and the differential signal dx/dt, respectively. A signal representative of algebraic sum x dy/dt--y dx/dt is generated from the signals representative of products x dy/dt and y dx/dt. A signal representative of quotient of (x dy/dt-y dx/dt) divided by the displacement r.sup.

Abstract: Two embodiments of tachometers for engines that are capable of use with an engine that either has an external source of electrical power such as a battery or no external source of power. In one embodiment, the switching is accomplished manually and in another embodiment the switching is accomplished automatically whenever battery power is applied to the tachometer. A constant voltage system reduces noise generated by this system.

Abstract: A wide-band programmable tachometer and speedometer/odometer apparatus to detect the rotational speed of an output shaft of an engine in a vehicle and calculate the corresponding speed/mileage thereof. First, a converting device converts a mechanical motion of an engine into an electrical signal. Second, the electrical signal is amplified by two amplifiers and outputted as an amplified signal. Third, the amplified signal is sent to a frequency divider and then through a multiplexer. A selecting device is incorporated with the multiplexer to send out a signal with frequency in an operable range. An F-V converter is used to convert the signal from the multiplexer and to output a first, a second, and a third DC voltage. The second and the third DC voltages are used to drive a tachometer to display the rpm of an engine. The third DC voltage is sent to a V-F converter and through a monostable circuit unit and outputted as positive pulses.

Abstract: A travel detecting apparatus is disclosed which generates a pulse signal in response to vehicle motion and detects the actual rate of vehicle travel in accordance with the pulse signal. The apparatus comprises a speed or RPM sensor coupled to an automotive transmission for generating a first pulse signal representative of the vehicle speed or RPM, a tire-size setting switch for setting tire information relating to the dimensions of the tires of the vehicle, and a CPU for frequency converting the first pulse signal in response to the tire information to generate a second pulse and for detecting the rate of vehicle travel in accordance with the second pulse signal.

Abstract: A photo-optical coupler is connected to a shaft to provide a series of electronic pulses at a frequency corresponding to rotational velocity of the shaft. Apparatus electronics is responsive to frequency of such pulses for indicating a low speed alarm condition when such frequency is below a preselected threshold. The apparatus electronics includes a digital counter that is set to a first preselected count upon occurrence of each of the shaft rotation pulses, and which is thereafter decremented between the shaft rotation pulses. A low speed alarm condition is indicated if the counter reaches a count of zero prior to a succeeding shaft rotation pulse. In the preferred embodiment, the counter is decremented by an oscillator having a clock frequency coordinated with the first preselected count so as to activate the alarm when rotational velocity of the shaft decreases to a predetermined threshold percentage of a nominal rotational velocity of the shaft.

Abstract: A circuit for determining the speed of rotation of a wheel, has an inductive transmitter (1), the output of which is connected to a pulse-shaping device (7) whose output is connected to an evaluation device. The inductive transmitter is connected to an evaluation circuit (11) by means of a cable (6). The evaluation circuit is intended, on the one hand, to make certain that the input signal of the inductive transmitter (1) can be evaluated while, on the other hand, it should be able to detect errors which may occur, for instance due to a break in the cable (6) despite the presence of dirt resistances (R.sub.S). For this purpose, an auxiliary circuit (10) is provided which varies the internal resistance of the pulse-shaping device (7) as a function of the speed.

Abstract: A cryogenic gyroscope for detecting the angular velocity of a rigid system without reference to an external inertial system comprises a closed rigid casing made of a sueprconducting material and kept below its critical superconducting temperature, for example, by immersion in a bath of liquid helium. A rotation-detector device is situated within the superconductor casing. This device, which is rigidly supported by the wall of the casing, includes at least one component of ferromagnetic material, constituted by a plurality of ferromagnetic strips intercalated with layers of electrically-insulating material.

Abstract: A tachometer particularly adapted for operation as a rotational velocity feedback transducer is provided. First and second proximity detectors are used to monitor orthogonal positions of an irregular surface portion of a rotating shaft and provide x and y signals that are substantially in quadrature. The x and y signals are differentiated with respect to time to provide differential signals that are representative of dx/dt and dy/dt, respectively. Signals representative of products x dy/dt and y dx/dt are generated from the x signal and the differential signal dy/dt, and the y signal and the differential signal dx/dt, respectively. A signal representative of algebraic sum x dy/dt-y dx/dt is generated from the signals representative of products x dy/dt and y dx/dt. A signal representative of quotient of (x dy/dt-y dx/dt) divided by the square of the displacement r.sup.

Abstract: A meter driving device for indicating angular positions corresponding to input values. The device includes a memory for storing previously given input values, angular directions corresponding to the input values, and coefficients representative of the grades of change in angular direction depending on the change between adjacent two input values, as parameters. Based on these parameters and the frequency of input pulse signal giving the input values, the angular direction corresponding thereto is calculated. The angular direction signal receives PWM process and then supplies to a pair of crossed exciting coils via a driver. During a predetermined time period from the turning ON and OFF of the power source, the transference of the angular direction signals to the driver is shut out by logic gates, thereby inhibiting malfunctional meter indication.

Abstract: An non-intrusive tachometer for measuring engine RPM includes a hand-held probe having an antenna for sensing radio frequency electromagnetic signals radiated from an operative spark ignition engine. The probe includes means for providing a pulse signal indicative of plug firing events to signal processing means which executes a statistical algorithm to determine the time between spark plug firings and engine RPM. A visual display displays engine RPM. Automatic gain contol means provides the pulse signal with a relatively constant amplitude by compensating for the inherently wide variation in amplitude of the electromagnetic signals among different automobile ignition systems. The signal processing means and display are located separate from the probe in an emissions testing system, or the signal processing means and display are integrated within the probe.

Abstract: For measuring the rotational speed of a wheel is an antilocking protected vehicle brake system a rotational speed sensor is provided in which in accordance with the rotational speed of the wheel signals are electromagnetically induced which have an amplitude and frequency which increase regularly with the rotational speed. When due to error sources the amplitude of the induced signal does not increase with the frequency of the signal a rotational speed measured value is determined by means of the measured amplitude, i.e. not on the basis of the measured frequency. To avoid erroneous measuring signals it may likewise be provided that when the amplitude of the signal does not increase with its frequency the last measured value of the frequency of the induced signal at which the amplitude still increased with the frequency is used to determine the speed of rotation.

Abstract: A speedometer/tachometer assembly for an automotive vehicle, such as a heavy truck, has a ten section DIP switch for calibrating the speedometer and a like switch for calibrating the tachometer. When set to all "0's", each switch causes the corresponding meter to be driven by a variable frequency signal from a corresponding sensor, as calibrated by a corresponding calibration factor that has been preloaded in the non-volatile memory of a microprocessor that operates the meters. When set to all "1's", each switch causes the corresponding meter to be operated from pre-calibrated data appearing on a data link. When set to any other setting, the setting determines the calibration factor that is applied to the uncalibrated signal, and this is used to drive the corresponding meter.

Abstract: A velocity signal is obtained by calculating both the selected signal of the differentiated signal of the position signal from a position detector and the selected signal of the sinusoidal wave signal according to position displacement, so that a velocity detection produces a smaller velocity detection error at a low velocity and generates no ripple component even when a high velocity is detected.

Abstract: A signal representing the RPM of an internal combustion engine is produced by a signal processor connected to the battery of the vehicle. The signal processor derives an electrical signal from the battery which contains signal components produced by operation of the vehicle ignition system, as well as components from a multitude of other sources such as the voltage regulator, fans, air conditioning and other electrical systems of the vehicle. The signal processor filters and signal processes the signal derived from the vehicle battery to produce a signal having a frequency which is related to the RPM of the engine.

Abstract: Disclosed herein is a circuit for measuring off-sets of a rotary shaft. In the circuit, a difference in time is produced, by a given sampling time, between an off-set output signal to be inputted to a low-level output selector and another off-set output signal to be inputted thereto. Owing to the above time difference, even though each off-set output signal undergoes a stepwise variation due to each DC off-set, the variation occur in each off-set output signal at the time difference. It is therefore possible to select either one of the off-set output signals, namely, the low-level off-set output signal, whereby the off-set output signal can be produced as an output free of a voltage level indicative of a rise in the off-sets due to an external disturbance corresponding to the variation.

Abstract: A method of computing the rotating speed of a rotating body includes the steps of setting speed computation reference time periods with respect to a pulse train signal obtained from the output of a rotating speed sensor; measuring time length from the last pulse edge in the previous speed computation reference time period to the last pulse edge in the current speed computation reference time period; and computing the rotating speed of the rotating body on the basis of the result of the time length measurement. The time point when the previous procedure of speed computation terminated corresponds to the time point when the current procedure of speed computation starts, thus making it possible to achieve continuous speed computation. In this way, an enhanced accuracy can be achieved in speed measurement for low speed range, which leads to improved control performance in anti-lock control and traction control for the low speed range.

Abstract: A magnetic speed sensor air gap fault-detection arrangement having a two-input AND gate for each of the two-axle trucks of a railway vehicle for conditioning a gap process circuit common to each axle. Each of the gap process circuits of each axle is activated to provide a logical "1" output to an associated two-input AND gate. The associated two-input AND gates each outputs a logical "1" to a respective gap counter circuit when the axle rate reaches a predetermined value. The respective gap counter circuits count the logical "1's" and activate an associated gap fault check circuit to reset the respective gap counter circuit and to display an error code and to output a logical "1" signal to the dynamic diagnostic apparatus.

Abstract: A digital system for providing a series of pulses that are related to the angular position of an engine crankshaft. A square wave signal is developed which is applied to the input of a synchronous digital filter. The digital filter provides a noise-immune output signal. The digital filter has two counters or timers which are used to determine whether or not the high and low times of the input signal that is applied to the filter exceed predetermined time periods. Based on this determination the filter ignores or passes pulses of the square wave to the output of the filter.

Abstract: In an exercising apparatus for supporting a bicycle, a pivotally mounted member connects to a rear axle of the bike to constrain movement of the axle about the pivot point of the support member. A support roller, located on the horizontally opposite side of the rear axle as is the pivot point, cooperates with the support member to support the rear wheel. A flywheel and variable load means are connected to the roller to simulate the inertia and variable load experienced during the riding of a real bicycle. Preferably, a front fork support connects to the front fork of a bicycle and has an adjustable feature which can change the elevation of the bicycle frame. The front fork support is inclined and connected to this rear axle support member so that when a rider of a bicycle connected to the apparatus leans toward or shifts his weight toward the front fork support, the front fork support bends and the rear tire of the bicycle pivots toward the roller to maintain frictional contact between the tire and roller.

Abstract: A sensor is connectable with a load circuit via two conductors. The sensor receives its electrical power from the load circuit via the two conductors and similarly provides its output signal indicative of the sensed phenomenon via the same conductors. An unregulated source potential is provided to a terminal of the sensor from a supply potential via the load circuit. Voltage regulating circuitry in the sensor converts the unregulated source potential to a regulated operating potential for its active circuit elements. Certain output circuitry in the sensor is connected to the terminal having the unregulated source potential for conveying an output signal from the sensor to the load circuit.

Abstract: A method and circuit for monitoring phase voltages of a polyphase tachometer generator to detect a phase failure, where the tachometer generator is associated with a rotor position transmitter. The phase voltages are added up by a summing stage to form an auxiliary voltage. The auxiliary voltage is sampled at every commutation instant determined by a rotor position signal generated by the rotor position transmitter during a predetermined measuring time. This sampled voltage value is compared with a predetermined voltage value range. An indication of a tachometer fault is displayed as soon as a sampled voltage value is outside the predetermined voltage value range. By this method and circuit, a fault which occurs between two commutation instants can be detected at the next commutation instant.

Abstract: A method and an apparatus for measuring a flight path parameter of a projectile (7) or parts thereof during flight possibly into the region of the target, with the electrical charge imparted to the projectile (7) or its part by friction with the air and/or by the gas fumes generated during ignition or detonation being detected by means of at least one inductively operating sensor (1) and the zero passage of the resulting signal is evaluated. The resulting signal can be utilized to measure time of flight, velocity, a time pattern for the distribution of fragments or the like.

Abstract: A driving circuit for driving a crossed-coil type instrument used for reading a physical quantity in which a pair of windings surrounding a movable magnet carrying a pointer needle thereon are disposed to cross each other with a predetermined mechanical angle. The driving circuit comprises a digital data conversion circuit supplied with an electrical signal representing the physical quantity to be measured for producing a digital data representing the electrical signal, a pulse data producing circuit supplied with the digital data for producing a number of pulses in correspondence with the digital data, and a drive signal generating circuit supplied with the pulses for generating first and second analog drive signals therefrom. The driving signals are respectively supplied to the first and second windings for moving the magnet disposed in the first and second windings.

Abstract: This invention relates to apparatus for producing a periodic output signal having a predetermined period ratio (a/b) relative to a periodic input signal.Signals from a tachometer on a gearbox are received by a counter timer unit, the counter timer unit evaluates the number of clock pulses k.sup.o received from a clock within each period of the tacho signal. A control unit receives values of k.sup.o from the counter timer and employs an algorithm based on the following equation to calculate a count value n.sup.o to be loaded into a register for the next tacho period. ##EQU1## where dK represents k.sup.-1 -k.sup.o. An accumulator is connected via an adder to the register and at receipt of each clock pulse from the clock adds the count stored in register into the accumulator. An output is produced on line when the accumulator overflows.

Abstract: A method to disengage an electronic speed control as a function of the condition of the park/neutral gear or manual clutch. If the automatic transmission lever is bumped from "drive" or the manual transmission clutch is depressed while the electronic speed control is operating, the method will sense this by detecting a difference in the ratio of engine speed to vehicle speed. If the ratio changes by .+-.25 percent, the electronic speed control is disengaged.

Abstract: An ignition monitoring circuit for an ignition system of an internal combustion engine of an automobile, which comprises, in addition to a pulse height and a pulse width shaper circuit, a circuit for eliminating an initial erroneous pulse which is generated from the pulse width shaper circuit upon making of the key switch. The pulse height shaper circuit shapes impulses corresponding to an ignition voltage into pulses of predetermined height; the pulse width shaper circuit shapes the output pulses of the pulse height shaper circuit into pulses of predetermined width. The eliminating circuit comprises: a serial circuit of a resistor, a diode, and a capacitor, coupled across the battery; and a transistor, having its base coupled to the output terminal of the pulse height shaper circuit through an inverter, which is coupled in parallel with the serial connection of the diode and the capacitor.

Abstract: A digital wristwatch having a case and strap also serves as a computer to display speed, distance, and pedaling cadence when temporarily attached to a holder on the bicycle handlebar. Wheel and sprocket sensors are connected to electrical terminals in the holder. The wristwatch is provided with external electrical terminals connected to a microcomputer in the watchcase which uses signals from the sensors when the watchcase is temporarily retained in the holder. The microcomputer is preprogrammed to provide an improved dual mode circuit which keeps time in a "watch mode" and which uses the sensor signals to make speed, distance, and cadence computations and display them in a "bike mode." The computations may be altered and new constants entered in a "calibration mode," through manual actuators. Changes of state within a mode are responsive to manually actuated push-buttons, to lapse of predetermined time periods or to condition of an annunciator.

Abstract: A vehicle speed detecting device utilizes two vehicle speed pulse generators, a vehicle speed memory device, pulse counters, abnormality detectors, pulse signal transfer devices and an alarm device which are all integrated into the electronic control circuit of a micro-processor through two sets of signal processing devices. The detecting device not only indicates the speed of the vehicle but also detects abnormalities in either of the vehicle speed pulse generators and provides an appropriate alarm.

Abstract: A method and an apparatus for determining angular velocity from two voltage signals which are produced by an angle transmitter (1) have a sinusoidal function with respect to the angle of rotation of a rotatable member and are shifted in phase by 90 angular degrees. The amount and sign of the angular velocity (.omega.) are determined by the division of the derivative of a first voltage signal with respect to time by the second voltage signal. In that signal range in which the second voltage signal has passages through zero, the derivative of the second voltage signal with respect to time is divided by the first voltage signal. Alternatively, the amount of the angular velocity (.omega.) is determined from the vector sum of the derivatives of the two voltage signals with respect to time. The sign of the angular velocity is determined from the two voltage signals and their derivatives.

Abstract: An apparatus for testing a cross-coil instrument having a pointer, a sensor for sensing a condition to produce a sensor signal indicative of the sensed condition, and a converter coupled to the sensor for converting the sensor signal to a deflection of the pointer. The apparatus comprises a fault detector coupled to the sensor for detecting a disconnection fault to produce a command signal, and a test signal generator responsive to the command signal for generating a predetermined test signal to the converter, thereby moving the pointer to a predetermined position. The operation accuracy of the cross-coil instrument may be checked from the difference between the actual and predetermined pointer positions when a connector provided in a signal line between the sensor and the fault detector is pulled out.

Abstract: Quadrature input signals from an opto-electronic or magnetic readhead which is movable relative to a periodically marked scale, are respectively multiplied by quadrature reference signals from a reference oscillator in multipliers. The resulting signals are added together in a mixer to give a signal (S) having a frequency which is the reference frequency shifted by the frequency of the input signals. This signal (S) is then compared with the reference signal. The reference signals are generated from a high frequency clock which is subsequently used to compare the period of the reference signal with that of the signal (S), giving outputs which interpolate the position of the readhead within the pitch of the marks on the scale.

Abstract: Speed error is calculated by finding the difference between set speed and vehicle speed and then filtering the result. The error is tested for polarity and magnitude before selecting a desired acceleration rate. This acceleration rate is used in an acceleration based electronic speed control system for vehicles.

Abstract: A digital system for providing pulses that represent the position of an engine crankshaft that has a digital filter for filtering out pulses caused by noise. A square wave signal having voltage pulses that represent crankshaft position is applied to the input of the filter. The filter determines whether or not the high and low time periods of the square wave signal exceed a predetermined time period and based on this determination ignores or passes pulses of the square wave to the output of the filter.

Abstract: A movement parameter sensor for sensing of parameters of movement between a stator member defining a frame of reference and a rotor member movable relative to the stationary member about a rotation axis. The sensor includes field providing means for generating an electric field located at the stator member, the field providing means including a pole arrangement comprising an array of four source electrode means arranged adjacent to each other along a field line around the rotation axis. The field providing means includes an excitation signal generator for generating four equal frequency excitation signals at 90 degree increments of phase, each one of the four excitation signals being applied to a respective one of the four source electrode means such that a virtually moving electric field is created at the source electrode means so that the electric field effectively moves relative to the stator member along the field line.

Abstract: This invention is directed to a combination touchless (photo type) and contact type tachometer having a digital display for measuring high, medium and low rotating and surface speeds. Mechanical rotation may be detected by a photo emitting-receiving sensor on the left-hand end of the device or by the contact transmitter located on the right-hand side. The received signal is amplified by an amplifier circuit and regulated by a regulator circuit. Subsequently the data is processed by a standard micro-processor IC circuit, for performing calculations, unit conversion and display decoding. The speed and other information are precisely displayed by a shiftable and reversible, rotatable 180.degree., digital displaying unit to achieve the advantages of an easy to read, precise, economical and effective tachometer.

Abstract: A method and an apparatus for determining angular velocity from two voltage signals which are produced by an angle transmitter (1) having a sinusoidal function with respect to the angle of rotation of a rotatable member and are shifted in phase by 90 angular degrees. The amount and sign of the angular velocity (.omega.) are determined by the division of the derivative of a first voltage signal with respect to time by the second voltage signal when said second voltage is above zero. In that signal range in which the second voltage signal passes below zero, the derivative of the second voltage signal with respect to time is divided by the first voltage signal. Alternatively, the amount of the angular velocity (.omega.) is determined from the vector sum of the derivatives of the two voltage signals with respect to time. The sign of the angular velocity is determined from the two voltage signals and their derivatives.

Abstract: An apparatus for detecting the speed and position of a rotating shaft of an electrical motor. A commutator is provided having three or more poles. First and second brushes are provided in sliding contact with the commutator for supplying electrical power to the poles of the commutator. At least one of the poles is in electrical communication with the shaft. Rotation detection means measure the electrical potential difference between the shaft and ground and generate a rotation information signal in response to the changes in the electrical potential difference as the shaft rotates.

Abstract: An apparatus for detecting a disconnection of a sensor by monitoring a signal in a signal-carrying line for receiving an output signal of the sensor through a connector. The apparatus includes a feeder circuit for causing a current to flow through the connector to the sensor for a predetermined time period in the absence of the output signal of the sensor. The current flow causes elimination of an oxide film produced in the connector with time, resulting in the prevention of attenuation of the output signal due to the oxide film and in ensuring accurate detection of the disconnection of the sensor irrespective of secular change.