Abstract: Even when detecting the primary voltage of the primary coil side, without detecting the secondary voltage of the secondary coil side of high voltage, it is desired to provide a discharge state detecting apparatus of an internal combustion engine which can detect a spark discharge state with good accuracy, by reducing influences of the discharge current and the resistance component of the discharge path of the secondary coil side, which are generated in the primary voltage. A discharge state detecting apparatus of an internal combustion engine performs correction which reduces a signal component generated by the secondary current in the ignition coil from the primary voltage detected by the primary voltage detector, based on the detected secondary current, and outputs a primary voltage after correction; and determines a spark discharge state based on the primary voltage after correction.

Abstract: An engine testing apparatus is provided with a memory portion for storing a control command value obtained when the rotation speed of a dynamometer is changed by the control command value in accordance with the change of the engine rotation speed in a real vehicle in a period in which the engine behavior in a real vehicle is reproduced without connecting the dynamometer to an engine under test. The engine testing apparatus is provided with an output portion that supplies the control command value stored in the memory portion to the dynamometer with reference to an engine output signal showing the start of the reproducing period.

Abstract: A sensor failure detection device includes a storage, a predictor, a calculator and a detector. The storage stores temperature information of individual sensors. The temperature information includes measured values of temperatures. The measured values of temperatures are measured by a plurality of sensors. The predictor predicts a temperature distribution by performing a thermal fluid simulation, on the basis of the temperature information received from a remaining sensor. The remaining sensor is a sensor of the plurality of sensors other than the test target sensor. The calculator calculates a difference value between a temperature at a position of the test target sensor in the temperature distribution and a temperature measured by the test target sensor. The detector detects that the difference value is higher than a predetermined value.

Abstract: A sensor assembly includes an annular target body disposed about a rotatable member outer surface and an annular angular position indicator with at least one angular position index corresponding to an angular position of the member. Radial displacement sensors are spaced circumferentially about the axis and radially outwardly from the target body outer surface. A reference sensor is disposed circumferentially between two of the radial displacement sensors, has an inner end spaced outwardly from the target body surface by a first spacing distance, and is configured to detect the target body. An angular displacement sensor is spaced axially from the reference sensor and has an inner end spaced outwardly from the position indicator surface by a second spacing distance. The angular sensor is located such that the second spacing distance is generally equal to the first spacing distance and such that the position index passes the sensor inner end.

Abstract: A control system for use in safety critical human/machine control interfaces is described, more particularly a joystick type control system and particularly a joystick type control system utilizing magnetic positional sensing. The control system provides a control input device having a movable magnet, a pole-piece frame arrangement positioned about the magnet, at least three magnetic flux sensors being positioned in said pole-piece frame arrangement and a monitoring arrangement for monitoring the output signal of each of said at least three sensors.

Abstract: An angular position sensor and method that relies on a stationary circular array of Hall sensors and a rotatable circular array of magnets arranged about a common axis. A periodic and simultaneous reading of all of the Hall sensor outputs is used to determine angular velocity.

Abstract: The invention relates to an active sensor element for recording the speed of an exhaust gas turbocharger, comprising a suppressor circuit which has at least one diode. In order to specify a device for temperature measurement at the turbocharger and in particular at the turbocharger in the region of the active sensor, the current-voltage characteristics of the diode are evaluated for determining the temperature in the sensor element.

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

Abstract: A performance enhancement system incorporating a controller, an engine tachometer and a visual indicator light which illuminates within a predetermined range of engine RPMs and which may be separately mounted as required in the driver's visual focal plane to reduce visual distractions, aiding the driver in optimizing torque transference to the tires of a drag racing vehicle.

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 tachometer interface circuit is provided for use with a multi-functional measuring device. The tachometer interface circuit includes a conditioning circuit which receives a series of ignition pulses from an internal combustion engine. The conditioning circuit converts the series of ignition pulses into a series of output pulses each having a constant pulse width. The tachometer interface circuit further includes a magnitude sensing circuit and an offset circuit. The magnitude sensing circuit senses the magnitude of the ignition pulses and activates the offset circuit when the magnitude exceeds a predetermined limit. Upon activation, the offset circuit inserts a resistor into the conditioning circuit to reduce the magnitude of the ignition pulses entering the conditioning circuit. In this manner, the tachometer interface circuit of the present invention is able to operate with ignition pulses having a variety of magnitudes.

Abstract: An input voltage Va and a threshold voltage Vc are compared in a comparator 21 to shaping the waveform of a sensor signal. The period of the output signal of comparator 21 is measured by a period measuring circuit 4. A stepped waveform voltage generating circuit 5 generates a stepped waveform voltage based on the measured period. The stepped waveform voltage is converted into corresponding current in a V-I conversion circuit 6. The current of V-I conversion circuit 6 is supplied to a resistance 23d or 23e via an analog switch 22a or 22b which turns on or off in response to the operation of comparator 21, thereby applying a stepped offset voltage to input voltage Va threshold voltage Vc to perform the hysteresis operation.

Abstract: An engine monitor includes, in a self-contained preferably sealed unit, a spark sensor, inductively and capacitively coupled through the case to a spark pick up wire, a timer, and a running time detector, responsive to inputs from the spark pick up to provide total running time, job time, and service time metering. Preferably, storage means are included for storing maximum RPM and spark mode data, that is, data indicating the number of firings per RPM for the particular engine, as well as a preset service interval and one or more auxiliary timers.

Abstract: In a system and a method for determining the speed gradient dn/dt of a shaft of an internal combustion engine, the speed gradient dn/dt is determined as a function of the third power of the speed and the difference between two segment times in the control device. The speed gradient is only determined in phases which are not time-critical, while segment times are read in or stored only in time-critical phases so that the data required for controlling and regulating the internal combustion engine can be calculated in these time-critical phases independently from the determination of the speed gradient.

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

Abstract: A tachometer circuit for an outboard motor wherein battery voltage is switched from a signal generated in the capacitor discharge ignition system for providing a pulsating signal to drive the tachometer of a low voltage so as to reduce the sensitivity to noise.

Abstract: A tachometer signal generating device comprises signal coils which generate pulse signals corresponding to predetermined crank angle positions in synchronism with revolution of an engine, and a microcomputer which generates ignition control signals or fuel control signals on the basis of the pulse signals and which generates a tachometer signal of 6 pulses/one revolution.

Abstract: An apparatus (10) for use on electronically controlled fuel injection systems senses speed, angular position, and direction of rotation using only a single Hall effect type sensor (24). A disk element (14) is fixedly connected to and rotatable with the camshaft of an internal combustion engine. The disk element (14) includes a plurality of circumferential zones (16a-16x) of substantially identical length with each zone (16a-16x) having first (18a-18x) and second (20a-20x) areas. A first portion 16c-16t, 16v-16x) of these circumferential zones (16a-16x) have first (18c-18t, 18v-18x) and second areas (20c-20t, 20v-20x) which are substantially different in length than the first (18a, 18b, 18u) and second areas (20a, 20b, 20u) of a second portion ( 16a, 16b, 16u) of the circumferential zones (16a-16x).

Abstract: A tachometer signal conditioning circuit (20) includes a timer circuit (48) responsive to ignition pulses from the primary lead (28) of an internal combustion engine ignition coil (26), and outputting a timing pulse terminating after a given time delay interval during which RFI, EMI and other transients on the primary lead (28) are ignored. A one shot monostable multivibrator circuit (56) responds to the trailing edge of the timing pulse and outputs a trigger pulse of given duration. A switch circuit (66) is connected to the battery circuit (22) and is turned on by the leading edge of the trigger pulse and turned off by the trailing edge of the trigger pulse, all before the next ignition pulse. The switch circuit (66) has a node (80) providing an input for a standard low voltage tachometer (82). Conductive and nonconductive states of the switch circuit (66) change the battery circuit voltage at the node (80) at a frequency corresponding to the frequency of the ignition pulses.

Abstract: An engine rotation speed detecting apparatus comprises circuitry for sensing the state of operation of an engine, circuitry for setting a plurality of respectively different masking periods of time, circuitry for detecting an ignition signal lasting for a period of time longer than any one of the plural masking periods of time thereby detecting an ignition period defined between adjacent ignition signals, and circuitry for computing the rotation speed of the engine on the basis of the detected ignition period, one of the plural masking periods of time being selected according to the result of sensing by the operation state sensing circuitry.

Abstract: A digital tachometer (2) is provided for two and four cycle internal combustion engines. A transformer (14) senses ignition pulses on the primary lead (6) of the ignition coil (4) of the two cycle engine, and an electrical connector (64) senses ignition pulses at the primary lead post terminal (66) of the ignition coil (54) of the four cycle engine. First and second signal conditioning circuits (50 and 96) are provided for each ignition pulse sensor for polarity immunity, RFI suppression, and transient and overvoltage protection. A precision timer (166) responds to pulses from the signal conditioning circuitry and outputs an output pulse of given delay, and ignores other pulses from the signal conditioning circuitry during the given delay, to protect against transient false triggering, especially in breaker point ignition systems. A phase-locked loop (186) responds to the delay pulses and outputs a pulse train having a frequency which is a function of frequency of the delay pulses.

Abstract: This system includes hysteresis comparison means (6, 9) whose output goes from a first state to a second state when the voltage of the ignition signal (S.sub.A) passes a predetermined high threshold and returns from the second state to the first state when the voltage of the ignition signal drops below a predetermined low threshold, a flip-flop circuit (8) triggered by the means of comparison (6, 9), and whose output delivers the said synchronous signal (S.sub.S), and a duration discriminator circuit (7) which only authorizes the switching over the flip-flop circuit (8) in response to the change in the output of the comparison means (6, 9) from the second state to the first state when the said output remains in the first state for a duration at least equal to a predetermined value. This invention may be used for measurement of the speed of an internal combustion engine.

Abstract: An improved input circuit for an electronic vehicle speed control unit is disclosed. An ignition current sensor coil is adapted to have a voltage differential signal induced therein each time an ignition pulse is generated by the vehicle engine. Electrical noise signals generated by the vehicle engine appear as common mode signals across the ignition current sensor coil. The ignition current sensor coil is connected at each end to a capacitor, both of which are connected to ground potential. The ends of the ignition current sensor coil are further connected to the inputs of a differential amplifier. The capacitors appear in a series loop with the ignition current sensor coil for the differential voltage signals and, consequently, provide tuning for inductance. However, the capacitors appear in parallel with one another to ground potential with respect to the common mode noise signals, thereby providing high frequency noise rejection for the input circuit.

Abstract: Two embodiments of improved electric tachometers for outboard motors wherein the tachometer and its driving sensor are mounted on the protective cowling of the power head of the motor and the sensor derives an electrical signal through an air gap so that no mechanical connection is required between the engine and the tachometer.

Abstract: A detection signal of a frequency corresponding to a rotational frequency is applied to a frequency-voltage converter and its converted voltage signal is provided to a sine-cosine current generator, from which sine-wave and cosine-wave currents having sine and cosine values corresponding to the voltage value of the voltage signal are supplied to a cross-coil rotary magnet type indicator for providing an indication of the rotational frequency by a pointer. When the power source is cut off, interruption of the power source voltage supply to the frequency-voltage converter and the sine-cosine current generator is delayed by delay means and, in the delay time, the input to the sine-cosine current generator is reduced, returning the pointer to the zero point. The indicator further includes a zero-resetting magnet which interacts with the rotary magnet to force the pointer to move to said zero point.

Abstract: To determine the rotary speed of a toothed element (1), for example the starter gear of an internal combustion (IC) engine, or a toothed wheel coupled to a wheel of a vehicle for evaluation of the speed, and change in speed thereof, for use in a brake anti-block system, a magnetic field is generated, for example by a permanent magnet (3) which has both radial and tangential components with respect to the teeth (2) of the rotary element. A magnetic field dependent sensor (4) such as a Hall generator or a thin-film permalloy-type magneto-resistive sensor is positioned to respond to the tangential component of the magnetic field, to thereby eliminate shifts in the null or center line about which the field strength undulates as the disk rotates to permit ready evaluation of the output from the sensor by threshold circuitry.

Abstract: To positively allocate output signals from a transducer scanning marker elements arranged at a uniform distance from the center of a rotating disk, the markers are located around the circumference of the disk in accordance with a predetermined pattern, for example, uniformly distributed 30.degree. apart, or distributed with uniformly increasing relative distances, and an additional market element (33) and forming a reference marker is located in the zones between adjacent markers spaced from a neighboring marker element (21) of the plurality of marker elements by a distance which is substantially larger than the angular distance with respect to the marker element at the other side of the reference marker. The outputs from a pick-up sensor are evaluated by applying the outputs to two counters, counting a different clock rate, the count output of one of the counters being stored and compared with a subsequent count state of the other counter operating at a higher clock rate.

Abstract: A digital display type tachometer for an automobile for numerically displaying a rotation speed of the engine comprises a numeric character display device having display sections for 1000's, 100's, 10's and 1's digits, the 1's digit display section being constructed to display always "0", a counter for counting pulses generated in synchronism with the rotations of the engine to produce a BCD signal depending on the rotation speed, and decoding/driver means for decoding the BCD signal into decimal numeric character signals for 1000's, 100's and 10's digits and driving the 1000's, 100's, and 10's digit display sections by these character signals, respectively.

Abstract: In a detecting apparatus for indicating engine revolutions or vehicle speed, a counter is provided to count up, for a predetermined period of time, the number of pulses produced by an angle sensor. To improve the accuracy of the measurement, the time width during which the pulses are counted can be varied in accordance with a rotational speed of the engine. In this way, a larger measurement time period is provided at lower speeds than at higher speeds.

Abstract: An A.C. voltage picked up from the alternator driven by an internal combustion engine is converted into a pulse train signal so that the number of the pulses is counted for a period of time defined by a reference timing signal produced in synchronization with the rotation of the crankshaft of the engine. When the number of the pulses reaches a predetermined value during the period of time, a counter produces an output signal to indicate that the slipping rate of the belt is within a tolerance. On the other hand, when the number of pulses is less than the predetermined number, the counter does not produce an output signal (indicating that the slipping rate is over the tolerance). The output of the counter may be averaged over a plurality of measuring times.

Abstract: A multi-function device using two ICs, with the precision ignition pulse frequency-to-voltage converted signal produced in the RPM portion being used as input to both ICs. Chatter pulses produced by an operational amplifier in the RPM limiter are utilized to shunt ignition pulses to ground in a proportional manner as engine speed approaches the selected maximum.

Abstract: To permit tests of: ignition timing; dwell angle; engine speed; and voltage levels, a pulse train is provided derived from the ignition system of the engine; the pulse train is applied to a frequency multiplier, preferably a phase locked loop (PLL) which provides a sequence of output pulses having a pulse repetition rate which is a multiple of the frequency of the signals or pulses of the pulse train. An AND gate has the multiplied signals applied thereto and is enabled, selectively, in accordance with the desired test. The output of the AND gate is applied to a counter which counts multiplied pulses within the interval of enabling of the AND gate, the output being applied to a digital indicator to provide a direct readable digital output; preferably, the multiplication rate is selected to provide a digital output indication which is directly readable in desired units.

Abstract: A system for detecting rotational frequency of engine which comprises a switching device including a switching transistor for switching on and off the flow of current to the ignition coil of an internal combustion engine and a current limiting circuit for limiting the flow of current to the switching transistor to a predetermined value, and a speed detecting circuit connected to the junction of the ignition coil and the switching transistor.

Abstract: In order to provide a tachometer which is accurate and easy to read, a number of light-emitting diodes is arranged in a row, each diode representing a predetermined increment of speed, rotational speed is measured and used to generate pulses, at a proportional rate, which are then decoded and used to drive the light emitting diodes over a predetermined time span, the diodes being lighted repeatedly in sequence at a rate exceeding the response time of the eye so as to present a flicker-free bar graph type display showing rotational speed.

Abstract: An electronic indicator device for providing an audible or visible indication when an internal combustion engine to which the device is fitted reaches a predetermined rotational speed so that the driver can, if he wishes, change gear or reduce speed in order to save fuel. The device includes a detector for sensing electrical impulses generated by the engine ignition circuit in operation thereof and for producing an output signal the frequency of which is related to engine speed. This frequency signal is converted to an analogue voltage signal in a frequency-to-voltage converter and the output of the converter is compared with a reference voltage to provide an electrical output signal to a lamp, buzzer or the like when the engine speed reaches the value determined by the reference voltage level.

Abstract: An electronic circuit for picking-up and shaping signals emitted from the breaker of a conventional or electronic ignition system is provided which consists of an infrared optical coupler in which the emitter is connected to the terminal common to both said breaker and the ignition coil of the ignition system via a circuit capable of calibrating said signals and in which the receiver of said infrared optical coupler is connected to the base of a transistor operating between the locked and the saturated condition wherein the output terminals of said transistor are connected to a circuit capable of eliminating stray signals.

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 speed shift indicating device is mounted in the driver compartment of a motor vehicle and is connected to the ignition system by a single wire which extends from the driver compartment through the firewall and into the engine compartment. The single wire derives from the ignition system an electrical input signal having a repetition rate indicative of engine revolutions per minute (RPM). The speed shift indicating device has an electrical circuit connected to the single wire for receiving an input electrical signal which has a repetition rate indicative of engine RPM. Trigger pulses are produced in response to the input electrical signal and are supplied to a timer. The output of the timer switches to a first state in response to each trigger pulse and remains in the first state only for a first time period unless another trigger pulse is received before the end of the first time period. The first time period is adjustable by the driver.

Abstract: A sample and hold frequency to voltage converter circuit particularly suitable for use in automotive applications as a tachometer or other speed indicating device. The converter uses circuit means, responsive to a periodically varying input signal, to generate first and second pulse trains. The pulses in the pulse trains have a repetition frequency and duty cycle that varies as a function of the frequency of the input signal. An integrator is provided for generating a voltage proportional to the duty cycle of the second pulse train. A transmission gate is controlled by the first pulse train and couples the integrator to a capacitor. The capacitor is charged or discharged, almost instantaneously, each time the transmission gate is rendered conductive by a pulse from the first pulse train. The capacitor then develops a voltage which is proportional to the frequency of the input signal.

Abstract: A phase-controlled pulse signal generator, comprising a magnetic field source born by a rotating shaft, and a Hall effect sensor submitted to the field, the sinusoidal signal delivered being processed by a phase correcting circuit controlled by the speed of the shaft, followed by a triggered pulse circuit.

Abstract: A stroboscope which generates high intensity light flashes may be manually adjusted to the speed of a rotating object and provides an indication of the speed of the rotating object in revolutions per minute. Connection of an external synchronizing unit into the stroboscope automatically disables the manually-controlled oscillator and substitutes synchronizing control pulses derived from a rotating object which is to be synchronized, these control pulses occurring at a frequency which is sixty times the frequency of the rotating object.

Abstract: The disclosure describes an improved tachometer for displaying the speed of an engine which produces ignition pulses. The tachometer includes a pulse-forming circuit, a meter, and a capacitor connected in series with the meter. A rectifier enables the transmission of a current pulse through the capacitor and meter in response to each timing pulse. A discharge device momentarily interconnects the opposed plates of the capacitor in response to the terminal of each timing pulse, whereby the voltage on the capacitor is dissipated. The meter indicates the speed of the engine by responding to the frequency of the current pulses. The discharge device includes a diode and transistor connected across the capacitor.

Abstract: The invention contemplates tachometer apparatus which functions from an electric pulse input which is of frequency directly related to engine speed of an internal combustion engine. In application to a modern automobile assembly line wherein successively assembled vehicles may have various-sized engines in random succession, the particular feature of the invention is that with essentially the same rectifier circuit and associated indicating meter, and with the simplest of manipulation or connection of a single element, the meter can be direct-reading and fully calibrated whether the invention is applied to a four-cylinder engine, to an eight-cylinder engine or to a six-cylinder engine.

Abstract: A calibration circuit and method for use with systems of the type displaying values of a measured condition in response to electrical pulses received at the system input in which the repetition rate of the received pulses is representative of the value of the measured condition. Electrical pulses, having a known repetition rate are generated for simulating a value of the measured condition in response to a reference signal of known frequency, the repetition rate of said simulating pulses being determined by the frequency of the reference signal.

Abstract: This invention provides a speed sensitive device for controlling the speed of an engine. A tachometric generator is provided which supplies a voltage or a function of the engine speed, and this is compared with a reference voltage which is a fraction of the voltage of the battery.In a first stage of the comparison the voltage supplied by the tachometric generator is compared with a reference voltage fixed by a dividing bridge, which determines a comparison threshold so that, when the voltage supplied by the tachometric generator exceeds this threshold, the first stage triggers a second stage of comparison, similar to the first, which compares the voltage from the first stage with another reference voltage fixed by a second dividing bridge, this second triggering causing actuation of a switching component to modify the ignition of the engine.