Abstract: An integral information and energy storage system is disclosed comprising a disk drive having a housing, a shaft rotatably mounted therein, and a disk platter coupled to the shaft. A flywheel is also coupled to the shaft and includes, embedded in the flywheel, magnets having magnetic fields emanating therefrom. Electrical coils are positioned in the housing for receiving electrical energy from a power supply line and generating an electromagnetic field effective for selectively repulsing or attracting the magnets to thereby rotate the flywheel and convert electrical energy in the coils into kinetic energy in the flywheel. Alternatively, if power is not available on the power supply line, the coils generate electrical energy as the magnetic field is caused from rotation of the flywheel and the magnet embedded therein to move across the coil, thereby converting kinetic energy in the flywheel back into electrical energy in the coil and to the power supply line.

Abstract: A resolver rate sensor is disclosed in which dual brushless resolvers are mechanically coupled to the same output shaft. Diverse inputs are provided to each resolver by providing the first resolver with a DC input and the second resolver with an AC sinusoidal input. A trigonometric identity in which the sum of the squares of the sin and cosine components equal one is used to advantage in providing a sensor of increased accuracy. The first resolver may have a fixed or variable DC input to permit dynamic adjustment of resolver sensitivity thus permitting a wide range of coverage. In one embodiment of the invention the outputs of the first resolver are directly inputted into two separate multipliers and the outputs of the second resolver are inputted into the two separate multipliers, after being demodulated in a pair of demodulator circuits. The multiplied signals are then added in an adder circuit to provide a directional sensitive output.

Abstract: A sensor for measuring the difference between the velocity and/or position of a vibration-suppressing cylinder and that of a piston connected to a piston rod and moving back and forth inside the cylinder in a dashpot for motor vehicles. The sensor consists of a permanent magnet and of a winding in the form of a cylindrical coil and operating in conjunction with the magnet. The magnet is connected directly or indirectly to one of the mutually moving components and the winding is connected directly or indirectly to the other. The component that the magnet (5) rests against and the component that the winding (7) rests against constitute a complete circuit that carries the magnet's field.

Abstract: A circuit configuration which serves to condition the output signal of a rotational speed sensor, e.g., the wheel sensor of an automotive vehicle. The circuit configuration includes a trigger circuit, the "hysteresis" or trigger thresholds thereof being controllable, and includes circuits for determining a coupling factor which, multiplied by the frequency of the sensor signal corresponding to the speed of rotation, forms the amplitude of the sensor output signal. To determine the coupling factor, and to adjust the hysteresis, threshold values are predefined for the output signal of the rotational speed sensor. Upon start of the vehicle, the coupling factor is determined from the frequency of the sensor signal at the point of time the threshold values are reached, and the hysteresis is adjusted accordingly.

Abstract: A reluctance sensor produces reluctance signals in response to passing slots in a rotating wheel. When a given signal exceeds a threshold, a DIG.sub.-- OUT signal is produced. When the signal falls to zero, the DIG.sub.-- OUT signal is terminated. The invention adjusts the threshold, based on the magnitude of the reluctance signals. Since the magnitude of the reluctance signals depends on wheel speed, the invention, in effect, adjusts the threshold based on wheel speed, yet without independently measuring wheel speed.

Abstract: A linearly moving external part of a multi-cylinder internal combustion engine is contacted with a hand-held contact tachometer for producing a waveform signal which, along with a signal responsive to the ignition of each cylinder, are applied to an engine analyzer processor for display of a single engine cycle of the waveform signal on the CRT oscilloscope of the engine analyzer. The variations and amplitude of the waveform signal correspond to speed variations of the moving part over an engine cycle to give an indication of the relative power contributions of the individual cylinders. Cylinder ignition markers and cylinder zone markers are respectively displayed at the top and bottom of the screen, respectively corresponding to the cylinders in their ignition order. Each cylinder zone marker is delayed a predetermined time from its corresponding cylinder ignition marker and indicates the time period during which the engine responds to the ignition event of the corresponding cylinder.

Abstract: A method and apparatus for generating a voltage (u.sub.DK) proportional to the rotational-speed uses a resolver (2), which outputs two path-dependent or angle-dependent, amplitude-modulated (AM) sinusoidal voltages (S.sub.1, S.sub.2) in phase quadrature. The sinusoidal voltages have amplitudes that can be modulated depending upon the rotor position or the angle of rotation (.alpha.), and can be tapped. According to the invention, a sinusoidal amplitude signal (R.sub.L1, R.sub.L2) dependent on the rotor position or the angle of rotation (.alpha.) is extracted from the two AM sinusoidal voltages (S.sub.1, S.sub.2). These sinusoidal amplitude signals (R.sub.1, R.sub.L2) are converted into an approximated, sinusoidal signal (R.sub.L1A, R.sub.L2A), which is linear around the zero crossing in a range of.+-.45.degree.. Each approximated, sinusoidal signal (R.sub.L1A, R.sub.L2A) is differentiated and subsequently inverted; and an analog rotational-speed-proportional voltage (u.sub.

Abstract: This specification discloses inventions of a rotation detecting device for a rotary shaft and of a rotation controlling apparatus using this rotation detecting device. The rotation detecting device according to the invention comprises a signal generator for generating two signals vary their amplitude in accordance with the rotation angle of the rotary shaft and have a predetermined phase difference therebetween, part for correcting the respective center voltages output from the signal generator, part for correcting a deviation from the phase deviation between the two signals, and part for correcting the rotating amounts of the rotary shaft on the basis of the corrected two signal. The rotating amounts are represented in terms of rotating angles. A rotating torque can be obtained by calculating a difference between the rotating angles measured at two points apart from each other on the rotary shaft. The rotary shaft can be controlled in accordance with the rotating angle or the rotating torque.

Abstract: An angular velocity sensor is provided with a spherical liquid inertia mass, preferably mercury, which can rotate with respect to a vessel in which it is contained. A magnetic field passes through the inertial mass and the electrode pairs. One electrode of each pair of electrodes between which a voltage is measured is located in the center and the other near the wall of the spherical mass and/or in which the direction of the magnetic field is invariable in space.

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: The present invention provides a system for controlling the rotational speed of a rotary member such as a video tape recorder drum or the like. The system detects a zero crossing interval in the output of a frequency generator, adding it to the subsequent zero crossing interval in the delayed output signal and using the result to control the motor or the like.

Abstract: An apparatus for developing a signal voltage that represents the angular position of the crankshaft of an internal combustion engine. The apparatus includes a variable reluctance sensor that has a pick-up coil. The sensor is associated with means driven by the crankshaft of the engine for causing an alternating voltage to be induced in the pick-up coil as the crankshaft rotates. The apparatus includes a negative voltage clamp which clamps the voltage of a junction of the clamp circuit to substantially ground potential during negative half-cycles of the alternating voltage induced in the pick-up coil. The clamp circuit is adapted to be connected to a control circuit that is an integrated circuit having a bulk substrate diode. The clamp circuit prevents forward biasing of the bulk substrate diode.

Abstract: An apparatus for detecting speed sensor failure in an overspeed protection device is disclosed. The apparatus comprises a plurality of tachometers having outputs for indicating the speed of rotation of a machine relative to plural setpoints. If the comparison indicates that certain conditions exist, then a sensor failue is indicated. The apparatus may also be employed to detect a failure of, or loss of power to or within, one of the tachometers.

Abstract: An electronic motion sensor is described, wherein a cavity formed in a case of high flux density material supports a permanent magnet at the bottom. The permanent magnet has a north/south pole orientation in line with the cavity axis. A circular channel is located above, having an axis coincident with the cavity axis and which is filled with mercury. A center contact post is located long the cavity axis in contact with the mercury, extending upwards through the top of the channel. An amplifier circuit supported on a header of high flux density material is placed on top of the channel. The amplifier amplifies the potential difference between the center contact and the case. The header effectively seals the cavity of the case.

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 current carrying drive coil in a magnetic field is moved by the field. An attached tachometer coil, passing through the same field, produces a voltage from which the speed of the coils may be calculated. Changes in the drive coil current produce noise in the tachometer coil. This noise is offset by combining the tachometer voltage with the voltage produced by a stationary pickup coil, which picks up only the noise.

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 position transducer has an input shaft coupled to a variable inductance sensor to produce an output electrical signal representing shift angle position. The transducer includes a plurality of rigid circuit boards which are hinged to one another so that the circuit boards and the electronic circuitry supported on the boards can be wrapped around the variable inductance sensor. The individual rigid circuit board segments are laminated onto a flexible sheet having conductive tracks. The track sheet provides the hinged effect.The power supply which is mounted on one or more of the boards provides DC power through an AC circuit fed by a transistor which is switched on and off as a function of the power needs of the transducer. By thus having an ON duty cycle substantially less than 100 percent, the heat generated in the power supply is minimized thereby making feasible the packing density afforded by the plurality of hinged circuit boards.

Abstract: Apparatus for detecting the speed of a moving object when exposed to primary magnetic flux fields and secondary external magnetic flux fields. The apparatus includes a magnetic device which generates the primary magnetic flux fields, a multi-coil device which carries induced electric currents when exposed to the primary magnetic flux field, and an error correction circuit for offsetting the effect of the magnetic flux from the external magnetic flux sources on the induced electric current. A support device is positioned between the multi-coil device and the magnetic device to allow relative movement therebetween, corresponding to the movement of the object.

Abstract: Disclosed is a Runout Velocity and Acceleration tester which converts an analog acceleration signal to a digital signal. The individual bits of digital data are then transformed into an exponential function. The exponential function that results is then solved for the worst case acceleration on a surface.

Abstract: A device is disclosed for in situ detecting of axial motion of a generally cylindrical member in which both ends of the member are unavailable for the installation of a prewound coil. The device comprises a predetermined length of generally flat multiconductor cable. A first connector component is secured to one end of the cable, the first connector component having a plurality of electrical contacts, the number of contacts being at least two greater than the number of conductors of the cable. A second connector component is secured to the other end of the cable, the second connector component having a plurality of electrical contacts, the number of contacts being at least two greater than the number of conductors of the cable.

Abstract: A self guided vehicle employs a highly accurate velocity sensor to determine vehicle speed and position. The velocity sensor includes a resolver connected to and rotatable with a ground engaging wheel. A resolver to digital converter (R/D) provides a highly accurate 8-bit digital signal representative of the angle of wheel rotation. A second less expensive and less accurate velocity sensor also receives the modulated sine and cosine signals from the resolver and produces a series of pulses representative of vehicle speed. The pulses are produced by detecting the zero crossings of the sine, cosine, and combinations of the sine and cosine signals. The velocity information present in the second velocity sensor signal is not used to actually guide the vehicle, but merely to generally validate the information present in the R/D signal.

Abstract: A tachometric device is provided with a D.C. electric motor a shaft of which drives a pair of permanent magnets to rotate. A first permanent magnet controls a speed indicator unit; a second permanent magnet is rotatably mounted within a winding the terminals of which are connected to a negative feed back circuit for controlling the speed of the motor.

Abstract: A method for monitoring of a tachometer signal is suggested, wherein the tachometer output signal is not only monitored with respect to its presence, but in addition also with respect to its plausibility. One exemplified embodiment may be realized with the assistance of a correspondingly programmed computer, wherein the tachometer signal change is checked to determine whether it is within predetermined limits. Furthermore, a possibility of reciprocating switching between erroneous and non-erroneous speed signals is eliminated.

Abstract: A signal whose frequency is proportional to a rotational speed of a rotor and whose rising and falling angles near points crossing zero becomes larger with the rotational speed of the rotor is used to produce a first signal of amplitude corresponding to the rising and falling angles and a second signal of amplitude corresponding to the frequency, a difference between the first and second signals is evaluated, and the first or second signals are corrected with the difference.

Abstract: A method is provided for displaying the speed and the distance on board a motor vehicle. The shaft of an auxiliary motor drives a speed indicator and a mileage recorder and its rotation controls a train of pulses. The speed of rotation of the auxiliary motor is controlled so that the period of the train of pulses and the total number of pulses are slaved respectively to the period of another train of pulses and to their total number, this other train of pulses being controlled by the rotation of one of the wheels of the vehicle.

Abstract: A speed control system comprises a speed control unit and a test unit. The control unit has a Hall effect transducer for producing a signal representative of vehicle speed and a comparator for comparing that signal with a voltage reference source from which a control signal may be produced to control the vehicle throttle in the event of a disparity so as to maintain vehicle speed at a preset limit. The test unit is employed to set the voltage reference source.

Abstract: Automatic guided vehicles require an accurate method and apparatus for determining vehicle velocity. The subject apparatus is associated with a vehicle having at least one surface engaging idler wheel. A resolver produces a rotation angle rate signal having a value responsive to the angular rotation rate of the idler wheel. A resolver-to-digital converter receives the rotation rate angle signal and produces a rotation rate pulse signal. A clock substantially continuously produces clock pulse signals having a predetermined frequency. A counter receives the rotation rate pulse signal and the clock pulse signal and controllably produces a time signal corresponding to the number of clock pulses received over the duration of a predetermined portion of the rotation rate pulse signal. A logic device controllably receives the time signal and produces a vehicle velocity signal.

Abstract: A brushless resolver has first and second ring-shaped magnetic pole elements spaced from each other along a common axis. An excitation coil is wound axially between the two pole elements. First and second output coils are wound through the first and second pole elements and spaced radially from each other. A rotor is within the pole elements and has a shaft extending along the axis. First and second magnetic coupling elements are spaced along the shaft each of which being coplanar with a different one of the pole elements. Each coupling element providing 180 degrees of magnetic coupling with respect to the corresponding pole element. A high frequency signal applied to the excitations coil is transformer coupled to the output signals. The degree of coupling varies with the position of the coupling elements. The demodulated signal from each of the output coils has a triangular shaped waveform which may be directly differentiated to produce the angular velocity of the rotor shaft.

Abstract: A magnetic tachometer for generating a signal as a function of the velocity of a transducer positioning arm in a disk drive. The tachometer is formed by a pair of fixed parallel coils separated by a distance sufficient to allow a magnet, attached to a counterbalance portion of the rotary positioning arm, to move therebetween and thus to generate a voltage as a function of the velocity of the magnet. The coils are each wound over a thin armature member which is saturated by the magnet's magnetic field and they are differentially coupled to produce common mode rejection.

Abstract: A shaft angle encoder comprises a code disc (21) mountable coaxially upon a rotary shaft (20) whose angular position is to be continuously measured. Coarse-bit angular position data are encoded digitally in Gray code by a pattern of opaque and transparent sectors provided on a plurality of inner annular tracks on the code disc (21). Fine-bit angular position data are encoded in analog triangular waveforms generated by the outermost annular track on the code disc (21). The analog position data are converted to fine-bit digital values, which are combined with coarse-bit digital values to obtain an angular position measurement. Alignment of the fine-bit digital values with the coarse-bit digital values obtained from the Gray code position data is accomplished by using information provided by overlapping the least significant bit of the coarse-bit digital values with the most significant bit of the fine-code digital values.

Abstract: A generator providing both tachometer and synchro outputs and comprising a magnetic stator and a corresponding armature structure. The generator stator structure produces a composite magnetic field of both constant (DC) and alternating (AC) flux. The rotor directs the composite flux field through a plurality of sensing coils, each producing a signal from the sensed composite magnetic field and rotor motion, and which coil signal is separated into separate signal components. The components are processed to produce a synchro output which preferrably has standard Hall-effect equivalent signals, as well as providing a tachometer output voltage proportional to the rotor rotational velocity and direction.

Abstract: An electronic motor control system is taught herein which utilizes a tachometer check circuit. The tachometer check circuit is an electrical circuit which is interconnected with the output terminals of the tachometer. The circuit is utilized when the tachometer is at standstill to determine if the tachometer is functional, that is, is it internally correctly wired to produce an expected signal upon rotation. If such is the case, then motor start-up may take place. A second test is performed after motor start-up for determining if an appropriate amount of output voltage is being produced by the tachometer during the start-up phase. This is based on expected values of voltage during a short period of time after start-up. If such is not the case, the motor control system is disabled and the motor is stopped. The system is utilized for embodiments which include AC tachometers as well as DC tachometers used on unidirectional or bidirectional rotational systems.

Abstract: A speed detecting apparatus having a detector (101) for generating two sine-wave signals (PA, PB) which are .pi./2 out of phase with each other and have a frequency proportional to the speed of rotation of a motor so that actual-speed voltages (V.sub.L, V.sub.H) can be produced which are proportional to the speed of rotation of the motor. The speed detecting apparatus includes a quadrupling circuit and a frequency-to-voltage converter 107. Also included is a first speed generator for generating the actual-speed voltage (V.sub.H) in a high-speed range and a second speed generator which includes a four-phase rectangular signal generating circuit (106), a differentiating circuit (109), and a synchronous rectifier circuit (110) for producing the actual-speed voltage (V.sub.L) in a low-speed range. The voltages generated by the first and second speed generators are selectively issued as an output depending on whether the motor rotates at a high speed or a low speed.

Abstract: A flat coil velocity transducer includes a thin, flat coil mounted to a member whose velocity is to be measured. The convolutions of the coil are skewed so that regions at opposite ends of the coil contain predominantly upper or lower legs of the convolutions. The coil moves transverse to a magnetic field to induce voltage in the legs of the coil. However, the field induces voltage in one, but not the other, end region so that a resultant voltage is induced in the coil dependent on the strength and direction of the magnetic field, the number and length of the legs in the region, and the direction and velocity of movement.

Abstract: An apparatus for measuring and monitoring the angular velocity of the shaft of a rotating machine. In this apparatus, a plurality of sensors is positioned adjacent the shaft of the rotating machine for generating sequential pulses with periods proportional to the angular velocity of the shaft. The pulses are generated at intervals such that, during the period between adjacent pulses from one sensor, pulses are generated by each of the other sensors. An oscillator is provided for generating reference pulses at a predetermined pulse repetition rate, and a plurality of counting devices are coupled to respective sensors and to the output of the oscillator for counting the pulses generated by the oscillator. An averaging and reciprocal circuit is coupled to the output terminals of the counting devices for obtaining the average of the counting device outputs and then generating the reciprocal of the average value.

Abstract: A velocity detecting apparatus using a resolver, and more specifically, a two-phase resolver which rotor is connected to a rotary drive means such as a motor, a source for exciting the primary windings of the resolver, a wave shaper which produces a square wave of the same period and phase as the output signal produced by the secondary windings of the resolver, a phase discriminator which rectifies the output signal of the wave shaper, a low pass filter for producing a triangular wave from the output signal of the phase discriminator and a circuit for producing a signal corresponding to the absolute value of the slope of the triangular wave.

Abstract: A rotating member having a plurality of electrodes at a predetermined pitch is secured to a rotating body of a rotary machine, opposite to the rotating member a stationary member having a plurality of electrodes at the same pitch as that of the rotating member is arranged, and a variation in electrostatic capacity between the electrodes of the rotating member and the electrodes of the stationary member is detected so as to produce an output corresponding to a rotational speed of the rotating body of the rotary machine in accordance with the variation in electrostatic capacity.

Abstract: An optical shaft angle encoder which provides sensor output voltages having waveform characteristics modified for use with "multiplication type" tachometer converter circuits to provide improved servo control system performance by reducing step changes in the tachometer output voltage due to phase error and reducing tachometer output voltage ripple. The geometry of the encoder mask combination provides a non-sinusoidal sensor output voltage comprised of linear and parabolic segments having a trapezoidal derivative.

Abstract: In order to develop a suitable analogous voltage to the speed of operation of slow moving machinery having cyclical characteristics, the instant invention provides means for generation of a repetitive electrical input signal for each revolution of cycle of machine operation. The time between repetitions of the input signal is measured, the reciprocal of the elapsed time between cycles or revolutions is calculated, appropriately scaled, and presented as a voltage analog which is proportional to the speed at which the machinery operates. This voltage analog signal may be utilized in conjunction with analog or digital totalizing circuitry to provide totalized signals that may be used to identify the point at which preventative maintenance should be conducted.

Abstract: A time base signal for controlling the recording of binary data is developed by measuring the velocity of a magnetic record.The velocity is measured by providing an inductive read head and a magnetoresistive read head which sense the same flux field on the magnetic record. The difference in the outputs of these read heads is a measure of the record velocity.

Abstract: A transducer circuit includes a transducer device connected to be driven by a rotary member the speed of which it is required to measure. The transducer device produces output pulses at specific angular positions which are counted by an n-bit counter and which are also used to clock an m-bit latch circuit. Pulses from a clock pulse generator are counted by an m-bit counter, which has its data outputs connected to the data inputs of the latch circuit. An output register is connected to the n-bit counter and the latch circuit to receive an n+m bit code therefrom each time the m-bit counter produces a carry out pulse. Thus the n+m code in the output register contains data relating to the number of pulses produced by the transducer device in the fixed interval between carry out pulses and data relating to the number of pulses produced by the clock between the start of that interval and the instant when the last transducer device pulse was produced.

Abstract: An electronic tachometer utilizes a transducer, typically an optical encoder disc, connected to a movable mechanical element. The transducer produces a pair of triangular waves of fixed relative phase, each having slopes proportional to the velocity of the mechanical element. The triangular waves are differentiated and the resultant signals are sampled by gating pulses derived from the triangular waves themselves. The samples are combined to produce an output signal having a magnitude proportional to element speed and a polarity indicative of direction.In a combined system in which the transducer is attached to the shaft of a brushless motor, another output of the same transducer is used for commutation control of the motor stator windings. This arrangement is particularly useful in a velocity servo system, in which the tachometer output is compared with a signal indicating desired motor velocity. The comparator output is used to modify the commutation control so as to produce the desired motor velocity.

Abstract: This invention relates to a method of and apparatus for controlling the operation of a vehicle by means of electrical signals generated in a manner dependent on the road speed of the vehicle wherein the method comprises setting up a specific magnetic field in association with a normally unmagnetized component of the vehicle which rotates at a speed proportional to the road speed of the vehicle and sensing variations in the magnetic field in a coil located on the opposite side of a ferromagnetic member of the vehicle to the component and amplifying the signal through a high gain amplifier.

Abstract: A brushless tachometer is disclosed which provides a DC output voltage which is a direct function of an instrumented shaft's rotational velocity. The DC voltage is bi-directional, changing sign when the shafts direction of rotation is reversed. The disclosed tachometer preferably utilizes a brushless printed circuit resolver having a large number of poles. The sine and cosine outputs from the resolver are fed to a phase shifting circuit which provides two output signals whose frequencies are related to the speed of rotation of the shaft being instrumented. The frequency of one of the signals increases as the shaft speed increases while the frequency of the other signal decreases as the shaft speed increases. These two signals having frequencies related to shaft speed are fed to frequency to voltage converters. The outputs from the frequency to voltage converters are fed to a differential amplifier whose output is the DC signal which is indicative of the direction and the speed of rotation of the shaft.

Abstract: An angular rate sensor is conceived which operates by utilizing electrica conducting fluid flowing in a transverse magnetic field. The electric field induced in the flow direction due to rotation will produce a signal that is proportional to angular rate.

Abstract: A system and method for measuring the rotational speed of a variable speed drive shaft for a ship or the like with high accuracy over a wide range of speeds. Means associated with the shaft sense the time interval for each turn of the shaft, or fraction thereof. Such time interval is accurately measured and then converted to an r.p.m. value. Steps in the method include counting the number of cycles of an oscillating signal in binary form to measure the time interval for each turn, selecting a most significant portion of bits within the number counted, determining the positional weight of the most significant bit to obtain a scaling factor, and producing a voltage inversely proportional to the value of the selected portion of bits, which voltage is then scaled by the scaling factor.

Abstract: A brushless tachometer utilizing four stator windings and series connected field effect transistor commutation switches to provide an input to a summing amplifier. Connection of the field effect transistor switches to the summing junction of the amplifier and use of series resistance and back-to-back clamping diodes on the winding side of the field effect transistors permits commutation switching with a minimum of transient voltage changes due to interruption of the stator winding current.

Abstract: Diesel engine speed is sensed by a thermistor which is disposed within an air inlet of the engine manifold so that the resistance of the thermistor varies in accordance with the temperature of the air within the inlet and thus in accordance with the speed of the engine. The thermistor is connected in a transistor circuit which derives, in response to the change in resistance of the thermistor, an electric signal having a frequency which varies in accordance with engine speed.

Abstract: A generator providing both tachometer and synchro outputs and comprising a magnetic stator and a corresponding armature structure. The generator stator structure produces a composite magnetic field of both constant (DC) and alternating (AC) flux. The rotor directs the composite flux field through a plurality of sensing coils, each producing a signal from the sensed composite magnetic field and rotor motion, and which coil signal is separated into separate signal components. The components are processed to produce a synchro output which preferrably has standard Hall-effect equivalent signals, as well as providing a tachometer output voltage proportional to the rotor rotational velocity and direction.