Abstract: An interface for coupling data between a host computer/server and a bank of disk drives. The interface includes a chassis having disposed therein: a pair of storage processors adapted for coupling to the host computer/server; and, a pair of management controllers in communication one with the other through a communication link. The management controllers monitor elements of the interface including fans and power supplies and control such elements in response to massages passing between the management controllers.

Abstract: A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine, when the permanent magnet synchronous machine is fed with a frequency converter, the method comprising the steps of forming a stator voltage reference for the permanent magnet synchronous machine, injecting a high frequency signal (uc) into the stator voltage reference, measuring a DC-link current (idc) of the frequency converter when the permanent magnet synchronous machine (4) is fed with a voltage (Us,ref) corresponding to a sum of the stator voltage reference and the injected signal, calculating a stator current estimate (îs), calculating a current error (?s) as a difference between the stator current estimate and the measured DC-link current, and estimating a rotor speed ({circumflex over (?)}m) and position ({circumflex over (?)}m) of the permanent synchronous machine based on the current error.

Abstract: A sensor package apparatus includes a lead frame substrate that supports one or more electrical components, which are connected to and located on the lead frame substrate. A plurality of wire bonds are also provided, which electrically connect the electrical components to the lead frame substrate, wherein the lead frame substrate is encapsulated by a thermoset plastic to protect the plurality of wire bonds and at least one electrical component, thereby providing a sensor package apparatus comprising the lead frame substrate, the electrical component(s), and the wire bonds, while eliminating a need for a Printed Circuit Board (PCB) or a ceramic substrate in place of the lead frame substrate as a part of the sensor package apparatus. A conductive epoxy can also be provided for maintaining a connection of the electrical component(s) to the lead frame substrate. The electrical components can constitute, for example, an IC chip and/or a sensing element (e.g., a magnetoresistive component) or sense die.

Abstract: An automated transmission system includes a transmission brake which is used to apply a braking torque to the transmission, while the engine torque is negative and a transmission clutch is disengaged to effect a gear downshift, in order to avoid acceleration of the vehicle when the clutch is released and abrupt deceleration of the vehicle upon completion of the gear downshift.

Abstract: In order to prevent stator windings and power amplification semiconductor devices from being damaged by heat when a rotor is locked, a current feed term setting circuit that maintains an output signal circuit of a logical circuit in “OFF” state to completely cut off currents to the stator windings, when the number of repetitions of “ON” and “OFF” states of the output signal circuit reaches a predetermined value, is added to a driving IC of a control circuit for a brushless DC motor equipped with a protective circuit.

Abstract: A method of measuring a liquid crystal response speed includes steps of generating a sample pulse having a target voltage level and a variable voltage level that varies according to a response characteristic of a display panel, applying the sample pulse to the display panel, detecting the response characteristic of the display panel by the sample pulse, adjusting the variable voltage level until a desired level of the response characteristic is obtained, and generating modulating data representing the setting of the variable voltage level when the desired level of the response characteristic is obtained.

Abstract: A test circuit aids in accurately measuring the input pin to output pin signal propagation speed through an integrated circuit by providing a D flip-flop in the signal path near the output pad to register the arrival of a test signal transition. The flip-flop is clocked at various clock frequencies. At the high frequencies, test signal transitions applied at the input pad coincident with a clock transition having not arrived at the output pad in time to be registered at the next clock transition. At lower clock frequencies, the test transition has time to propagate through the integrated circuit and thus will be registered by the flip-flop. By successively lowering the clock frequency and sending test signals through the circuit, one-half of that clock period that just registers the test signal transition corresponds to the input-to-output delay time being measured.

Abstract: A high-resolution position sensor device for use in precise positioning of servomechanisms, by providing increased resolution using of an encoder mounted on the shaft of a motor, which produces transition pulses through a light-sensitive arrangement using a photodetector. Each time the pulse makes a transition because the groove of the encoder wheel has passed, a reset signal is produced which resets to zero the number of clock pulses which have been measured for that interval between the transition pulses. The transition pulses and the time between them changes with changes in motor speed, while the system clock pulse rate remains fixed. The invention provides a more accurate position sensor, which operates by generating more transition pulses than the encoder itself actually generates. If the encoder produces transition pulses at a given resolution, the sensor device produces output pulses having a higher resolution.

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

Abstract: To minimize change in duty ratio of an output signal brought about by a leakage flux and to obtain a sensor output stabilized even under an environment of use abundant of the leakage fluxes, a sensor-equipped bearing assembly 31 includes a rotatable race member 32 provided with a to-be-detected portion 1 having a magnetic characteristic in which N and S magnetic poles alternate with each other. In face-to-face relation with this to-be-detected portion 1, a magnetic detecting portion 2 is secured to a stationary race member 33. The magnetic detecting portion 2 is made up of magnetic sensors arranged in a direction circumferentially of the race members 32, 33 and each capable of providing an analog output. A differential output generating means 7 is provided for processing a differential output of the adjoining two magnetic sensors 2a and 2b as an encoder signal for one phase.

Abstract: A method and apparatus for sensing the speed and direction of a rotating target is disclosed. A first differential Hall package can be generally located opposite to a second differential Hall package, wherein the first differential Hall package and second differential Hall package comprise mirror images of one another. A first output signal can then be generated by the first differential Hall package and a second output signal by the second differential Hall package during a rotation of the rotating target. The first Hall output signal can thus be compared to the second Hall output signal during a shift of the rotating target from a sinusoidal phase to a non-sinusoidal phase thereof, thereby permitting accurate phase information indicative of the speed and direction of the rotating target to be obtained.

Abstract: In a vehicle wheel rotation detecting system, a signal input portion of an ECU accurately detects a vehicle wheel speed and a rotating direction of the vehicle wheel speed of the respective wheels. On the basis of the detected results, the respective computers are operated to perform ABS control, TC control and VSC control. When a computing result of the vehicle wheel speed is equal to or greater than a predetermined value, a change in the rotating direction is inhibited. This may prevent an error in the result of detection of the wheel rotating direction owing to an external magnetic filed and the like so as to further optimize the vehicle state control.

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

Abstract: An arrangement for sensing the rotational speeds of a wheel or any other rotating member includes a sensor module with a sensor element, a controllable current source with a modulator and a signal conditioning and evaluating circuit. The modulator controls the current source in response to the signals of the sensor element and/or external signals and, as an output signal of the sensor module, delivers a current signal representative of the rotational behavior with status or additional signals superposed on the current signal. The evaluating circuit of the sensor module includes at least two different signal-conditioning networks which, by way of a control network, in dependence on predetermined criteria or conditions, are connected between the sensor element and the modulator controlling the current source and take care of signal conditioning.

Abstract: A bicycle computer includes a base member structured to mount to a structural member of a bicycle. A cover having an inner surface is swingably coupled to the base so that the inner surface may be moved from a closed position where the inner surface faces the base member to an open position where the inner surface may be viewed or accessed by a user.

Abstract: A processor system and method for accurately determining true ground speed in a vehicle having wheel-axles propelled by traction motors is provided. The vehicle is equipped with a radar unit for providing a radar signal indicative of vehicle speed relative to the ground. The radar signal is accurate when averaged over a sufficiently long period of time but may be susceptible to undesirable short term variations. The vehicle is further equipped with speed sensors coupled to the wheel-axles to supply respective wheel-axle speed signals. The respective wheel-axle speed signals may be accurate over a sufficiently short period of time but may also be susceptible to undesirable long term variations.

Abstract: A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is squared. The squared outputs associated with each winding are combined, with the square root being taken of such combination, to produce a DC output proportional only to the rate of rotation of the motor's shaft.

Abstract: A high performance tachometer is provided for use in high performance racing vehicles, such as dragsters. The tachometer has an input signal indicative of the vehicular engine speed and an output display for displaying the instantaneous engine speed as indicated by the input signal. The tachometer includes input controls for directing the control and operation of the tachometer. Special features associated with the tachometer include a shift indicator. The system is designed to monitor an engine speed or RPM profile and utilize information from this profile to operate the shift setpoint selection, shift display enablement and the shift indicator.

Abstract: A rotational speed sensing device is disclosed which comprises a reference member adapted to be rotated at a reference speed, a rotational device coaxial with the reference member, the rotational device adapted to be rotated at a speed, a sensor associated with either the reference member or the rotational device and being rotated, the sensor for determining a speed differential between the reference member and the rotational device, and a controller electrically connected to the reference member and the sensor, the controller for receiving signals from the reference member and the sensor indicative of the reference speed and the speed differential, the controller for determining the speed of rotation of the rotational device based upon the difference between the reference speed and the speed differential.

Abstract: A device for detecting electromagnetic stray effects in systems with at least two inductive sensors which provide an essentially periodic output signal, performs a signal evaluation for evaluating signals of the sensors, a test for detecting an electromagnetic stray effect, whether periods of the signals to be evaluated lie within a period length of expected stray effects, a test, if applicable, whether detected signal progressions have at least a progression typical for stray pick-up, plausibility tests by means of at least one further detected signal in which a signal to be checked is compared with parallel measured other signals, and detecting a stray effect only if all tested conditions provide a result which is typical for stray effects.

Abstract: A method for the exact determination of the speed of a rotating part, in particular the speed of the wheel of a motor vehicle, in which discontinuities present on the circumference of the rotating part are scanned without contact, an electric pulse being produced upon the detection of each discontinuity and the number of pulses thus produced being counted. In order definitely to be able to determine the dynamism of a rotating part without manufacturing tolerances of the incremental disks influencing this, the period of time within which all pulses of the rotating part are counted precisely once is determined, and the speed of the rotating part is determined therefrom.

Abstract: In a phase adjusting circuit, a signal generating circuit generates an internal signal based on an external signal and a feed-back signal. An output circuit outputs to a load circuit the internal signal having a first delay with respect to the generated internal signal from the signal generating circuit. A feed-back signal generating circuit delays the generated internal signal from the signal generating circuit by a sum of a second delay corresponding to the first delay and a third delay corresponding to a load of the load circuit, and outputs the delayed signal as the feed-back signal to the signal generating circuit.

Abstract: At certain operating points, a plausibility test of the detected rotational speed signals is used to recognize an existing defect. The operating point for implementing the plausibility test is determined when it is detected that the motor vehicle has accelerated. The operating point at which defects in speed sensors are detected is determined in a simple manner but in such a way that any defect which may be present can be recognized reliably.

Abstract: A safety control arrangement for escalators includes a detector for generating a trigger signal, and a microprocessor connected to a memory. A serial data communications bus connects the detector to the processor. The memory includes toggling and interrogating routines which permit verifying proper operability of the detector.

Abstract: The system detects and monitors the rotational speed N.sub.R of a rotor and the rotational speed N.sub.TL of a motor of a helicopter and includes first and second devices for detecting N.sub.R and N.sub.TL, and delivering signals to first and second processing units which are connected to a display unit for displaying N.sub.R and N.sub.TL. The second processing unit includes an electronic processing unit which receives the signals relating to N.sub.TL and the signals relating to N.sub.R and which is capable of comparing the values of N.sub.R and N.sub.TL in such a way that, if the difference between the values of N.sub.R and N.sub.TL is less than or equal to a predetermined threshold, the second processing unit controls the display of N.sub.R and N.sub.TL such that N.sub.R and N.sub.TL are aligned on the display unit.

Abstract: A wheel tachometer minimizes variances in the rate of revolution detected by the wheel velocity sensors of the tachometer due to assembling errors and improves the accuracy of the operation of driving force allocation. Sinusoidal wheel velocity signals vF and vR representing the rates of revolution of the front and rear wheels are produced respectively by front and rear wheel revolution sensors are subjected to wave shaping to obtain the rate of revolution of the front wheels nF and that of the rear wheels nR. When the rate of revolution of the front wheels nF and that of the rear wheels nR exceeds an initial threshold value V.sub.THMIN, the greater one of the rates of revolution nF and nR is used to update the threshold value V.sub.TH. Thereafter, the detected rates of revolution nF and nR are used for the wheel velocities of the front and rear wheels V.sub.F and V.sub.R when they exceed the threshold value V.sub.TH and zero is used for the wheel velocities of the front and rear wheels V.sub.F and V.sub.

Abstract: A detector 1, with its object of detection having operation characteristics that include a shift from a first state to a second state, outputs a signal e1 that corresponds to the operation characteristics of the object of detection. A first state detection circuit 2 generates a first output signal SA corresponding to the first state based upon the signal e1 provided by the detector 1. A second state detection circuit 3 generates a second output signal SB corresponding to the second state based upon the signal provided by the detector 1. The second output signal SB is generated only when the object of detection shifts from the first state to the second state in a normal manner while the first output signal SA is being generated. A state judgement circuit 4 generates a state judgement output signal Z on condition that there has been a period of time during which the first output signal SA and the second output signal SB have been both at high.

Abstract: A method is provided to compute the probable body speed of a vehicle equipped with a mini tire as a spare tire, specifically when the mini tire is mounted. The wheel speeds of the four wheels are measured, and if the speed does not satisfy the predetermined formula relating to the wheel base and tread of the vehicle to a wheel speed, then a probable vehicle body speed is derived by the normal method. The speed thus derived is corrected by the diameter of the mini tire to compute a new probable vehicle body speed.

Abstract: A method and a device for monitoring rotational speed sensors, in particular rotational speed sensors for identifying the wheel speed, are described. A fault is detected if a slip coefficient which is weighted with the time exceeds a threshold value.

Abstract: Method and system are provided for "filtering out" a faulty wheel speed input signal in a vehicle control system, such as an ABS and/or TC system in order to ensure that the faulty wheel speed input signal does not contaminate or corrupt wheel speed information contained in the other wheel speed input signals. If such faulty wheel speed input signal indicates an abnormally high speed, it will increase the other wheel speed information if undetected. The wheel speed information is essential in detecting wheel instability or slip. It is important that wheel speed is not over-estimated since this may result in false slip detection and false ABS activation. Over-estimation of the vehicle speed would occur if the information from a spinning wheel is not properly filtered or compensated for. In one embodiment of the present invention, a bad sensor is detected by detecting and compensating for a single outlying ramp (outlier) of wheel speed.

Abstract: The tachometer includes a microphone for disposition next to the exhaust of the vehicle and an accelerometer for disposition adjacent to its engine. A selected one of the outputs is connected to an ADC which provides digital samples to a central processing unit. Also, the ripple from the battery is sampled and provided to the CPU. The CPU calculates a constant representing the relationship of the frequencies of the ripple samples and the mechanical samples and responds to the ripple samples and the constant to provide output signals corresponding to the speed of the engine. The speed is displayed.

Abstract: The apparatus has a signal processor for determining the ground speed of a motor vehicle on the basis of the frequency of a wave transmitted from a transmitter and the frequency of the wave reflected by the ground surface and received by a receiver. The signal processor includes a relationship obtaining device for obtaining a relationship between an estimated vehicle speed obtained on the basis of the speed of a vehicle wheel, and a provisional speed determined on the basis of the frequencies of the transmitted and reflected waves, when the vehicle is in a steady running state in which the estimated vehicle speed accurately represents the actual vehicle speed. The signal processor determines the final vehicle speed on the basis of the obtained relationship.

Abstract: To prevent a great variation of a detected wheel velocity for a period of time after a front wheel sensor or a rear wheel sensor for detection of a wheel velocity actually fails until a microcomputer detects the failure, it is determined whether or not an output pulse period of a front wheel sensor is equal to or shorter than a predetermined period. When the output pulse period exceeds the predetermined period, it is determined that there is the possibility that the front wheel sensor may be in failure, thus a front wheel velocity for a predetermined number of control cycles before (a front wheel velocity before the failure) is adopted as a front wheel velocity of the present control cycle. Also, a rear wheel velocity is calculated in a similar manner. For a time after a failure actually occurs until the failure is detected by a microcomputer, driving force control is not started even if other starting conditions for driving force control are satisfied.

Abstract: A system, method and apparatus for use on vehicles having road wheels with pneumatic tires that includes sensors that produce signals that are a measure of the rotational speed of said wheels, indicators arranged to provide information to the driver of the vehicle, and a computer operably associated with said sensors and indicators. The computer is arranged to monitor the wheel speed sensors during vehicle operation, and to perform at least one of the functions of: determining a value that represents tire inflation pressure and signaling the driver when this value falls below a predetermined value, determining a value that represents tire inflation pressure and signaling this value to the driver, calculating a value that represents vehicle speed and signaling this value to the driver, and calculating a value that represents distance traveled by the vehicle and signaling this distance to the driver.

Abstract: A cruising control apparatus for a vehicle, which comprises a vehicle speed sensor, a command switch, a microcomputer for generating an actuator control signal and including a vehicle speed signal memory and a watch-dog signal generator for generating a pulse signal with a predetermined period, an actuator for driving a throttle valve, an actuator driving circuit for driving the actuator in response to the actuator control signal, a watch-dog signal detector for discriminating whether the pulse signal is normal or not, a prohibiting circuit for opening the actuator driving circuit when the pulse signal is abnormal, and the microcomputer further includes vehicle speed decision means for deciding the vehicle speed signal being higher than a predetermined upper limit signal or lower than a predetermined lower limit signal and means for maintaining the watch-dog signal generator in an OFF-state in response to the result of the vehicle speed decision means.

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: A device is disclosed which can detect and document tampering in the signal transmission path between speed measurement and/or mileage counting devices and the speed transmitters which are associated with these devices using the simplest possible means and so as to be suitable for large-scale series manufacture. The device provides that at least one movement transmitter, which senses forces which are typical of driving, is arranged inside the respective measurement device, and that an evaluating circuit is also provided, which delivers a signal which controls a recording arrangement when signals of a speed transmitter do not correspond with those of the movement transmitter.

Abstract: A filter for removing oscillations and transients from vehicle driveline component angular velocity measurement signals. The filter determines, from successive measurements of angular velocity, any angular acceleration of a driveline component. Predetermined sets of unity and fractional multipliers are assigned to respective ranges of angular acceleration. Each succeeding measurement of angular velocity is estimated by adding the product of a selected modifier value and the difference between the currently sensed and the previously estimated values of angular velocity to the previously estimated value of angular velocity. Multipliers are valued and selected so that, when angular accelerations are detected, relatively large percentages of the differences between currently sensed and previously estimated values of angular velocity are added a relatively small number of times to previously estimated values of angular velocity when the differences are relatively small.

Abstract: An electronic regulating system for regulating the supply of pressure medium to each brake cylinder of a vehicle having a plurality of wheels thereby preventing spinning of the wheels upon starting and locking of the wheels upon braking, comprises wheel speed sensors which detect the rotation of the wheels and which produce signals indicative of the individual rotational speeds of the wheels, and an electronic control unit which monitors the individual rotational speeds of the wheels and which controls the supply of the pressure medium to the brake cylinders based on the individual rotational speeds. The electronic control unit includes a speed signal processor which receives the signals produced by the wheel speed sensors and which determines the individual rotational speeds of the wheels and a vehicle reference speed therefrom.

Abstract: A velocity sensor for detecting velocity even in a low velocity range has a velocity detecting element including a movable micromember, a deviation amount detecting device, a holding device and a velocity signal calculating device. The movable micromember is rotatably supported around a center of gravity for generating a frictional force or a dynamical pressure that is proportional to a velocity of a fluid. The deviation amount detecting device detects a deviation amount around the center of gravity of the movable micromember to generate an output voltage, which is proportional to the detected deviation amount. The holding device provides a holding force, which is proportional to the output voltage of the deviation amount detecting device, to the movable micromember and holds the movable micromember to a position around the center of gravity. The velocity signal calculating device calculates a velocity signal from the output of the deviation amount detecting device.

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: Based on a desired center frequency and a frequency resolution for a signal to be measured which are entered via an operator section, a micro-CPU calculates the frequency dividing number, a preset value and a center value for the signal to be measured. The frequency dividing number is set in a frequency divider, which frequency divides the signal to be measured and provides the frequency-divided output to a continuous period-to-voltage converter. The continuous period-to-voltage converter counts clock pulses occurring in each frequency-divided period, measures the difference between fractions of time from both the beginning and the end of the frequency-divided period to the generation of the next clock pulses, respectively, and outputs, as a voltage corresponding to the frequency-divided period, the sum of a voltage corresponding to a predetermined number of consecutive low-order bits of a binary value, obtained by adding the preset value to the pulse count value, and the fractional time difference.

Abstract: A method of measuring the instantaneous shaft velocity of a rotary machine having a shaft with a plurality of circumferentially spaced markers thereon, comprises the steps of sensing the passage of the markers with at least two circumferentially spaced sensors mounted adjacent the shaft to generate pulses in response to the passage of the markers; for each of the sensors continually deriving from the pulses and estimated spacing signals representing an estimated spacing of the markers, a set of angular velocity signals representing the instantaneous shaft angular velocity at a given point in time t.sub.i ; and varying the estimated spacing signals on an iterative basis to attempt to match the sets of angular velocity signals derived from the respective sensors. The described method allows a more accurate ICAV (Instantaneous Crankshaft Angular Velocity) waveform to be produced than was possible using prior art techniques.

Abstract: A ratio measuring apparatus which allows continuous monitoring of two or more digital signals so as to yield an indication of the ratio of frequencies between such signals for use in process control. The apparatus includes a channel transfer circuit adapted to rotate inputs or outputs in the apparatus for logical orientation thereof. The apparatus further includes primary and secondary counters, each of which is coupled to an input signal for processing thereof. These counters operate relative to one another for logical processing of the input signals to yield ratio information. The primary counter is coupled to a data latch system, acting as a temporary memory storage for the measured ratio information. The data latch may also be coupled to a display means.

Abstract: A circuit configuration for editing, or processing the output signal of a speed sensor (5) includes a trigger circuit (1, 22), the changeover points or "hysteresis" of which are controllable, with the circuit configuration being furnished with circuits for determining the coupling factor (k), and with circuits for adjusting the hysteresis in response to the coupling factor. The coupling factor (k)--multiplied by the frequency of the sensor signal corresponding to the speed--forms the amplitude of the sensor output signal. With the coupling factor (k) being high, the hysteresis will be high, while it will be low with a low coupling factor.

Abstract: The capstan and drum servo systems of a VCR are tested by processing the capstan reference signal and the drum reference signal in a microprocessor and displaying information which is useful in diagnosing any defects in either of the servo systems.

Abstract: A calibration generator for furnishing signals to tachographs, taximeters and other instruments used in fleet management systems. Calibrated frequencies and amplitudes are provided by the generator of the invention. A PLL controlled synthesizer, driven by a crystal oscillator, supplies frequencies under control from the operator. An alternative continuously controlled oscillator is also available for tests.

Abstract: A centrifuge rotor overspeed protection system which can operate with rotors of at least two speed ranges. A set of coding elements are provided on the rotors coded to represent the actual maximum safe speed rating of the rotor. An additional set of coding elements coded to correspond to the maximum speed in the lower speed range are also provided such that the rotor can be operated at the maximum speed possible in a prior art centrifuge designed for operation in the lower speed range. The detection circuit for the coding elements automatically adjusts the detection threshold depending on the average values of the sensor output peaks corresponding to the codes.

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: The tachometer includes a microphone for disposition next to the exhaust of the vehicle and an accelerometer for disposition adjacent to its engine. A selected one of the outputs is connected to an ADC which provides digital samples to a central processing unit. Also, the ripple from the battery is sampled and provided to the CPU. The CPU calculates a constant representing the relationship of the frequencies of the ripple samples and the mechanical samples and responds to the ripple samples and the constant to provide output signals corresponding to the speed of the engine. The speed is displayed.