Abstract: This invention discloses a method for measuring the rate of angular displacement, of a traveling object, using magnetic field sensing, said method comprising: measuring magnetic field intensity and/or changes in said magnetic field intensity, projected onto a magnetic field sensor coupled to said traveling object, each measurement being per orthogonal rotation axis to provide a magnetic field intensity value per axis and/or a change in magnetic field intensity per axis, as said object's orientation changes with time; determining, number of peaks, present in a measurement sample comprising a set of said measurements, of time duration; and computing said rate of angular displacement, for said traveling object, as a function of said determined number of peaks and said time duration.

Abstract: A device for determining a tachometer characteristic curve of a motor vehicle includes a detection apparatus and a determining apparatus. The determining apparatus is configured to form a tachometer characteristic curve on the basis of one or more mean value pairs, which are formed by means of one locomotion signal mean value and one speed mean value, by means of which tachometer characteristic curve locomotion signals and speed values are converted into one another, and/or to change a tachometer characteristic curve which is already present.

Abstract: An air turbine start system is provided that includes an air turbine starter, a starter air valve, a turbine speed sensor, and a circuit. The starter air valve is movable between an open position, in which the pressurized air may flow into the air turbine starter, and a closed position, in which pressurized air does not flow into the air turbine starter. The turbine speed sensor is coupled to the air turbine starter, and is configured to sense the rotational speed of the turbine and supply a rotational speed signal representative thereof. The circuit is coupled to receive the rotational speed signal and is configured, upon receipt thereof, to determine whether the starter air valve is in the closed position or an open position.

Abstract: Methods and systems for use in monitoring a tachometer are provided. A method for use in correcting a signal from a tachometer coupled to a rotating shaft in a wind turbine includes receiving a raw tachometer signal from the tachometer coupled to a wind turbine shaft, the signal indicating the speed and/or angular position of the shaft, determining a cyclic error exists in the raw tachometer signal, and providing a corrective signal to adjust a torque within the wind turbine using the determined cyclic error.

Abstract: A management apparatus is described of a rotating motor and a load during power loss; the apparatus comprises a first switching circuit coupled with the rotating motor and a controller of said first switching circuit. The controller is configured to drive the first switching circuit so as to convert a back-electromotive force voltage developed in the rotating motor into a power supply voltage for the load. The first switching circuit is driven in accordance with a first duty cycle. The apparatus comprises a second switching circuit coupled with the load and driven in accordance with a second duty cycle. The controller is configured to vary said first and said second duty cycles to keep the power supply voltage for the load above or equal to a threshold voltage.

Abstract: A control device for a travel motor mounted to a vehicle has a resolver which works as a rotation-angle sensor. The control device has a RDC which calculates a rotation-angle output value ? based on rotation detection signals Sa, Sb transferred from the resolver. The control device supplies electric power to the travel motor based on the rotation angle output value ?. The RDC calculates “sin(???)” as an error deviation ? based on the signals Sa and Sb and the rotation-angle output value ?. The RDC calculates an angular acceleration by multiplying the error deviation ? with a gain (=Ka·Kb), and integrates the angular acceleration two times in order to obtain a next rotation-angle output value. A gain control part of the RDC decreases the gain when the judgment means judges that the travel motor rotates at a constant rotation speed.

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 stepper motor is initialized so that the exciting signal is applied to coils with the step shifted by half of one electric cycle from the rebounding step being synchronized with the timing when the stopper piece is brought into contact with a fixed stopper. The rebounding step, in which the rotor of the stepper motor reverses its rotating direction, can be easily detected. If the rebounding step can be detected, the position for initializing can be easily defined in the angle shifting manner as described above.

Abstract: A method for accurately estimating the rotational speed of a machine includes the steps of initializing a counter, measuring a position of the machine, incrementing the counter, waiting for a position update, measuring a next position of the machine, calculating a difference between the position measurement, measuring the amount of time elapse between positions, returning to the step of incrementing to the counter if the difference is less than a predetermined amount, returning to the step of incrementing the counter if the amount of time is less than a predetermined time, dividing the difference by the amount of time to determine the estimated rotational speed of the machine, and outputing the estimated rotational speed of the machine.

Abstract: A microprocessor controlled apparatus includes a microprocessor (2) with e.g. eight address lines (A,.sub.0,A.sub.1 . . . A.sub.7) on which signals may be applied by the microprocessor for selectively addressing a peripheral device coupled thereto, and a data device such as a LCD module (1) having data lines to which data signals may be applied for transfer into the data device. Four of the data lines (D.sub.0,D.sub.1,D.sub.2,D.sub.3) are coupled to a sub-set of the microprocessor address lines (A.sub.2,A.sub.3,A.sub.4,A.sub.5) excluding the two address lines (A.sub.0,A.sub.1) associated with the least significant bits. The signals on the sub-set of address lines are thus applied as data signals to the data device.

Abstract: A rotary speed measurement device includes an oscillator including a resonant circuit with a coil which conducts a resonant current to develop a magnetic field therearound. A wheel is connected to rotate together with a rotating member and is provided along circumference with alternately arranged first and second marks which causes different magnetic effect on the magnetic field. The coil is disposed adjacent the wheel so as to sense the magnetic effect and provide a corresponding voltage Vs. An analyzer is provided to give a parameter Vsub based upon voltage Vs and to compare the parameter with a predetermined threshold V.sub.TH to give a pulse when the parameter exceeds the threshold as indicative of that the wheel rotates by an increment corresponding to an angular distance between the first mark and the adjacent second mark. The pulse is counted by a counter within a unit time to obtain a rotary speed of the wheel.

Abstract: In a device for controlling the speed of a motor vehicle in which a power-setting member for the internal combustion engine of the vehicle can be displaced via a switchable coupling by an electric motor, the electric motor receives the voltage necessary for the displacement of the power-setting member for the speed to be maintained from a control device, and the coupling is adapted to be switched by means of an electromagnet for separating the motor from the power-setting member when the device for controlling the speed is not in action. A first controllable switch is connected between one pole of the source of operating voltage and the electromagnet and a second controllable switch is connected between the other pole of the source of operating voltage and the electromagnet. The switches are adapted to be switched into conductive state by means of an operating element.

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: A system 20 for measuring the sheet resistance of a conductive layer on the top surface of a semiconductor wafer 22 is disclosed herein. In one embodiment, the system includes a chuck 30 electrically coupled to the backside surface of the wafer 22. The chuck 30 is capable of supporting the wafer 22 electrostatically. A signal source 40 provides an excitation signal to the wafer 22 and circuitry for monitoring an induced signal is provided. The sheet resistance on the top surface of the wafer 22 is determined from the measurements of the excitation and induced electrical signals. Other systems and methods are also disclosed.

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: A circuit arrangement for generating a useful direct voltage signal associated with the frequency of an alternating current signal serves, in particular, to regulate the synchronism of an electric motor. It includes a comparator circuit (7) which converts the two opposite polarity half-waves of the alternating current signal of a tacho coil (2) into pulses whose edges trigger a measuring and control circuit (18) which generates direct voltages corresponding to the half-period durations of the alternating current signal measured from the respective zero passages.

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: A frequency-to-voltage converter, as applied to controlling the speed of a motor, comprises: a motor speed encoder (1) producing first and second alternating signals (3a,3b) each at the same, first frequency which frequency is dependent on the said speed, the first and second signals being in quadrature with each other; a reference oscillator (4), for producing third and fourth alternating signals (5a,5b) each at the same, reference frequency, which frequency is higher than said first frequency, the third and fourth signals being in quadrature with each other; and single sideband modulating means (6,7,8) connected to receive the first, second, third and fourth signals and to produce a fifth alternating signal (8a) which is a frequency-shifted version of one of the first and second signals.

Abstract: A vehicle speed control apparatus for automatically maintaining the vehicle speed of an automobile at a desired speed without the operation of the accelerator pedal, which apparatus includes an increase switch and a speed-increase means for continuously increasing the opening degree of the throttle valve when the increase switch is operated. When the increase switch is operated, the desired speed changes in response to the increasing actual speed of the automobile. The desired speed is finally determined to be the value of the actual vehicle speed just before the increase switch returns to the non-operating condition.

Abstract: An rpm-governing system for an internal combustion engine with auto-ignition is proposed, in which the fuel quantity to be injected at least in the event of idling is subject to the influence of an electromagnetic final control element, in which the control unit for forming the final control element trigger signal includes a regulator having PID behavior and in which the regulation signal is formed in accordance with the actual rpm/set-point rpm deviation. This rpm-governing system has an increase in rpm set-point value, with a retarded drop, this increase in set-point being made to follow up the increase in actual value. The PID regulator furthermore has a non-linear and preferably rpm-dependent P component. The signal end stage includes a pulse length modulator, the output signal of which triggers an electromagnetic final control element while there is a simultaneous current regulating action.

Abstract: This is concerned with a solid-state electronic brush speed sensing control for sensing the rotational speed of the brush in a vacuum cleaner, either of the canister or upright type, so that as the brush slows down or stops due to being jammed or partially jammed by a foreign object, such as a sock or the like, the drive motor will be disconnected from its source of power thereby protecting the brush, the motor, the belts, etc.

Abstract: Device for detecting the direction and change of rotational speed of a rotating element. In one embodiment, a pair of phototransistors which are energized by a light source according to an ordered sequence through a disk formed by opaque and transparent sectors coupled to the rotating element. The two phototransistors controls, when energized the switching on of two transistors which enable the discharge of two capacitors, charging with a predetermined time constant in the interval time between discharges. The discharge control action of one of the two phototransistors on a first capacitance is however conditioned by the charge level reached by the other capacitance and therefore both by the order in which phototransistors are energized and by the energization frequency. If the energization frequency is lower than a certain limit or the energization order is not the correct one, the first capacitor reaches a charge level higher than a reference value and supplies an indication signal accordingly.

Abstract: A vehicle speed system is described in which an electrical signal representing actual vehicle speed is compared with a stored signal representing desired vehicle speed. Any speed error is used in a servo loop to generate a control signal which tends to reduce the error to zero. In addition, signals representing the actual and desired vehicle speeds are compared in a comparator unit so as to produce a disabling signal when the actual vehicle speed either exceeds the desired speed by more than a predetermined amount, or falls below the desired speed by more than a predetermined amount, (e.g. because road conditions prevent the vehicle engine from driving the vehicle at or close to the desired speed). This enabling signal is used to switch the control system out of operation.

Abstract: In order to prevent ignition power losses at low engine speeds and further to provide for the use of ignition control signals of both unipolar and bipolar nature, the invention provides that a Schmitt trigger which generates the principal ignition control signal is actuated by the transducer. The switching thresholds of this Schmitt trigger are changeable by a secondary threshold recognition circuit which can shift at least the negative threshold of the principal threshold circuit to more positive values. The invention also includes a delay circuit which prevents the return of the shifted threshold to more negative values. Still further included is a third threshold circuit which is engaged only at some higher engine speed.

Abstract: Apparatus for monitoring the motion of a movable element, such as a rotatable shaft, comprising sensor means for producing a series of repetitive pulses in response to the motion of the movable element, ramp generator means for producing an increasing ramp signal, the ramp generator means including means for resetting the ramp signal to a starting level in response to each of the pulses, level detector means operable in response to the increase of the ramp signal above a predetermined level, and control means for performing a control function in response to the operation of the level detector means.

Abstract: A device comprising receiving means mounted on the vehicle, means for establishing an electrical reference voltage corresponding to the speed limit and means for controlling the speed of the vehicle response to the electrical reference voltage. It comprises a capacitor used as a memory connected to the speed control means and means for updating the voltage at the terminals of the capacitor, adapted for connecting an electrical voltage source to the terminals of the capacitor when the vehicle enters the information transmission field, then to isolate the capacitor from this voltage source after a given time.

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: A system for controlling the speed of a motor vehicle has a speed detector which produces a first electrical signal having a mean level relating to the actual speed of the vehicle and an alternating component whose amplitude is also related to the actual speed of the vehicle. A memory is provided for storing a second electrical signal which has a mean level related to the required vehicle speed and which is substantially free of any alternating component. A comparator compares the first and second electrical signals and therefore produces an error signal which has a mean level corresponding to the difference (if any) between the actual and required vehicle speed and an alternating component related to the actual vehicle speed. A servo responds to the amplitude of the error signal to adjust the actual speed of the vehicle towards the required value.

Abstract: A tachometer circuit for an engine having an alternator driven capacitive discharge ignition system functions as a frequency-to-current converter converting each ignition capacitor discharge into a precisely controlled amount of electric charge, which is then passed thru an indicating microammeter movement graduated in RPM. The precisely controlled electric charge is developed in a charge transfer capacitor, with the peak voltage appearing across the capacitor being regulated by a programmable transistorized voltage regulator. The temperature coefficient of the charge transfer capacitance is neutralized by the temperature coefficient of the voltage regulator, such that the product of capacitance multiplied by voltage--which is equivalent to charge--remains constant. The precisely controlled charge is initially established by machine trimming of a voltage--determining resistor in the voltage regulator, thereby allowing practical large volume manufacture of the circuit from unmatched components.

Abstract: A system for limiting the speed of a gasoline engine includes a circuit responsive to the engine speed which provides control signals to a solenoid valve which in turn controls a vacuum actuator. The vacuum actuator then overrides a manual throttle control to move the throttle toward closed position when a governed engine speed is approached. A control circuit provides a signal having four components; one proportional to engine speed, second and third proportional to engine acceleration and a fourth which is the integrated difference between the engine speed and a preset governed speed. In addition a speed switch actuated when an overspeed condition occurs is effective to inhibit the third component and to increase the fourth component to its maximum value to effect maximum governing action and system stability. The control signal controls a duty cycle oscillator which actuates the solenoid valve.

Abstract: A digital speed detecting circuit of the type in which pulses of a clock frequency are counted during a time interval of a cycle of the sinusoidal signal obtained from a sensor of the rotating member whose speed is being measured. The pulse count throughout the speed range of the rotating member is adjusted to be within a range best suited for accurate evaluation, since the pulse count exceeds this range at high and low speeds. This is accomplished in a first embodiment by shifting to a different counting frequency in different speed ranges and correcting the speed signal obtained by a factor corresponding to the degree of frequency change. In a second embodiment, the counting frequency is monitored and adjusted each cycle of the sinusoidal signal by comparing in a shift register the stage of advancement of a binary counter that produces the pulse count with a reference stage establishing the upper limit of the evaluation range.

Abstract: A cruise control system having means to provide a signal corresponding to a desired speed for use by a servo control to regulate the speed. This system uses a current source to ramp charge a first capacitor. A comparator compares magnitude of the voltage on the first capacitor against the signal representative of the desired speed. A first counter is used to accumulate counts from a first frequency generator. A latch counter capable of following the counts in the first counter is used to store the counts when the comparator indicates the voltage on the first capacitor is substantially equal to the magnitude of the signal representative of the speed. A digital comparator then compares the counts stored in the latch counter against counts being accumulated anew in the first counter while the first capacitor is being recharged. Means are provided to inhibit the first capacitor from being charged further after the digital comparator indicates equality between the quantity of the counts being compared.

Abstract: A speed-switch control comprising a multi-pole sub-fractional permanent magnet A.C. generator driven by a shaft; the generator develops an initial A.C. signal having an amplitude representative of the shaft speed, and that signal is applied to a threshold circuit where it is rectified and compared with a threshold amplitude correlated with a critical shaft speed range to generate a D.C. switch actuation signal. The D.C. switch actuation signal actuates a solid-state switching circuit to switch a controlled load, such as a safety interlock or alarm, into and out of an external operating circuit.

Abstract: A pair of polyphase electrical machines with interconnected rotor windings are mechanically coupled together and driven by a rotating shaft. One stator winding is excited by a fixed carrier frequency, and the output frequency at the other stator winding is proportional to shaft speed. The output signal frequency is not zero at zero shaft speed and is unique for both directions of shaft speed. Brushes, slip rings, and electrical connections to the rotating shaft are not required.

Abstract: In a circuit for producing a digital wheel speed signal from the duration of a half cycle alternation of the sinusoidal waveform produced by a wheel sensor, there is provided a control unit which operates a first counter until it reaches a count corresponding to the duration of the half cycle alternation of the sinusoidal waveform and in response to this occurrence effects operation of a second counter until the first counter reaches a predetermined final stage. A signal representing the duration of a half cycle alternation, which is inversely proportional to the angular wheel velocity is thus converted by the control unit so as to produce a wheel speed signal that is directly proportional to the angular wheel velocity. According to the present invention, the pulse frequency supplied to at least one of the first and second counters is adjusted according to the stage of the counter so as to change exponentially and thereby provide for faster generation of the wheel speed signal.

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