Abstract: A method of verifying a cylinder deactivation mode on an engine is provided. The method can include activating an ignition device in a deactivated cylinder during an exhaust stroke of the deactivated cylinder. The method can include measuring a voltage of the ignition device. The method can include comparing at least one of an amplitude and a timing of a measured spike of the voltage against a baseline voltage spike. The method can include indicating a status of the deactivation mode based on the comparison against the baseline voltage spike.

Abstract: A client computing system (CCS) receives a download including (i) an image representative of a vehicle component, (ii) symbol data associated with a first symbol, (iii) a set of one or more selectable identifiers, and (iv) supplemental information associated with the vehicle component. Each selectable identifier can indicate a respective portion of the supplemental information. After receiving the download, the CCS displays the image and the first symbol without displaying the set and the supplemental information. While the image and the first symbol are displayed without the set, the CCS receives a first input corresponding to selection of the first symbol. The CCS then responsively displays the set. While the set is displayed, the CCS receives a second input corresponding to selection of a first selectable identifier from the set. The CCS then responsively displays the respective portion of the supplemental information indicated by the first selectable identifier.

Abstract: The invention, while reducing noise, suppresses a load increase in a processor and a delay in drive control. An engine control unit includes a processor, a driving circuit including a switching element to drive a load such as a fuel injector and an ignition device, and a communication circuit that transmits control signals from the processor to the driving circuit via serial communication. The control signals each include a command frame for controlling the driving circuit and a data frame for driving the load. If a predetermined bits in each of the data frames received from the processor at predetermined time intervals are determined to be the same twice in succession, the engine control unit changes a state of a driving signal ‘Drive’ for driving the load and thereby changes an operating state of the switching element.

Abstract: To reduce the amount of exhausted unburned fuel and further improve fuel efficiency of an internal combustion engine 10 provided with an ignition device 12 that ignites fuel air mixture more forcefully than a spark discharge in a combustion chamber 20. The internal combustion engine 10 includes an internal combustion engine main body 11 formed with the combustion chamber 20 and the ignition device 12 that ignites the fuel air mixture more forcefully than the spark discharge in the combustion chamber 20. In addition, the internal combustion engine 10 includes an electromagnetic wave emission device 13 that emits an electromagnetic wave supplied from an electromagnetic wave oscillator 32 from an antenna 41. The electromagnetic wave emission device 13 emits the electromagnetic wave from the antenna 41, thereby creating an electric field for accelerating a propagation speed of a flame.

Abstract: A method includes characterizing the effects of an electric field on a first set of printed wiring boards (PWBs) by testing the first set of PWBs to generate test data, using the test data to determine a dielectric life curve of the first set of PWBs, and based on the dielectric life curve, defining a screening time and a screening voltage to screen for premature failures in a second set of PWBs due to electric fields.

Abstract: An apparatus and method is provided for testing a spark plug after the spark plug is assembled in an internal combustion engine. The apparatus includes a high voltage test probe to mechanically probe the spark plug. The high voltage test probe includes a non-electrically conductive part, an electrically conductive ring substantially shielded by the non-electrically conductive part, and a high voltage contactor for electrically connecting to a terminal end of the spark plug. The apparatus also includes a high voltage control box having a high voltage source and an electrical ground, and including at least one of an insulator crack detection circuit and a spark plug firing circuit. The method includes using the apparatus to test assembled spark plugs.

Abstract: According to the method for regulating the supply voltage of an electronic circuit a regulating element with variable resistivity and the outer supply voltage being applied to an input terminal of said regulating element is controlled by an amplified difference between a reference voltage and a part of a regulated supply voltage whereat at first an instant, on which the regulating circuit and the electronic circuit start operating, is detected, and then such value of the reference voltage is set on said instant that the regulated supply voltage will equal a maximum allowable supply voltage of the electronic circuit and the supplied electronic circuit puts itself in a state of a maximum current consumption. Then an operating voltage drop across said regulating element is measured at regular time intervals and the reference voltage is then each time reduced by one degree until said operating voltage drop is below or equals a chosen most appropriate value of said operating voltage drop.

Abstract: A device for measuring an ionization current of a spark plug of a type with a resonant structure, including a motor vehicle ignition system, the spark plug being coupled to a generator including a regulating capacitor. The generator includes a polarizer that polarizes the spark plug, connected between the generator and the spark plug, and a device that measures ionization current of the spark plug, connected between the regulating capacitor and ground.

Abstract: An improved hand held starting/charging system tester. According to one aspect of the present invention, the portable handheld tester includes a connector to which various test cables can be removably connected to the tester. Detection circuitry within the tester determines which of several types of test cable is connected to the tester before testing. According to another aspect of the present invention, the portable handheld tester includes an improved user interface that permits a user to review test data from previously performed tests and further permits a user to either skip a previously performed test (thereby retaining the previously collected data for that test) or re-do the test (thereby collecting new data for that test). According to yet another aspect of the present invention, the portable handheld tester that performs a more complete set of tests of the starting/charging system.

Abstract: When a resistance value of a CAN bus main line is 60 ?, the CAN bus main line is in a normal state. However, the resistance value thereof differs depending on an abnormality portion when an abnormality such as disconnection, short circuit, or the like has occurred in it or a branch line. Therefore, the abnormality portion can be identified depending on the measured resistance value. In addition, a failure diagnosis portion of an ECU stores different diagnosis trouble codes in the memory for the following cases; when an abnormality has occurred in the CAN bus communication, when various sensors are malfunctioning, and when an abnormality such as disconnection has occurred in a communication line that is connected to the various sensors. Accordingly, the resistance value of the CAN bus main line is measured, and the abnormality portion can be identified by a combination of the resistance value and the diagnosis trouble code.

Abstract: Disclosed is a multiple test system for use in vehicles for inspecting the operation of an ignition system. A high voltage waveform is applied to an ignition plug and detected by a Hall sensor. The multiple test system compares the detected voltage waveform with a reference value, and calculates maximum, minimum and mean values of the voltage waveform. Ignition energy is inspected by a user for determining if a component needs to be replaced.

Abstract: A low cost, easy to use, hand held pulse stream analyzer is designed to show, after an engine stops operating, which pulse stream, ignition or injection, quit first. Additionally, the analyzer is capable, using relative time domain analysis to comparatively analyze these pulse streams to the alternator ripple pulse stream, of determining if the fuel flow to the injectors quit, thus causing the engine to quit. This information quickly gives the technician a direction to investigate to find a responsible faulty component for the problem being experienced, and is especially helpful in attempting to diagnose intermittent faults in a much more efficient manner. The inventive device is usable on virtually all brands and types of gasoline powered vehicles.

Abstract: An ignition timing device for timing an engine having a timing port and a timing mark indicative of a position of a movable member. The ignition timing device includes a sensor adapted to be secured in the timing port to provide a timing mark signal indicative of presence of the timing mark. Also, an ignition sensor is adapted to provide an ignition signal indicative of the occurrence of an ignition spark. A filter receives the ignition signal and provides a filtered ignition signal. The filter filters ignition sparks of compression strokes from ignition sparks of compression and exhaust strokes of a selected cylinder to provide the filtered ignition signal. Also, the delay element is provided that receives the filtered ignition signal and provides a delayed signal having a selected delay from the filtered ignition signal. A comparator receives the timing mark signal and the delayed signal.

Abstract: A method of detecting spark plug fouling in an internal combustion engine is provided. The method comprises calculating an integration value of discharge current flowing between electrodes of a spark plug during a period of a spark discharge and judging if the calculated discharge current integration value is smaller than an integration value criterion. The integration value criterion is set at such a value that can discriminate between normal discharge and interior jumping (i.e., jumping due to short circuit caused by fouling). When the calculated discharge current integration value is smaller than the integration value criterion, it is judged that the spark plug has been fouled. By this, it becomes possible to detect a spark plug fouling before the electrodes of the spark plug are short-circuited and disabled to generate spark discharge, i.e., before the spark plug is fouled to such an extent as to cause a misfire. An ignition system for detecting spark plug fouling is also provided.

Abstract: A system for diagnosing a driver and detecting circuit anomalies therein includes: voltage comparator circuits for generating diagnostic logic signals, each of which indicates the existence of a corresponding type of anomaly; and a coding circuit to receive the diagnostic logic signals and to output information relating to an overall operating state of the driver. The coding circuit includes a first portion to provide at its output first logic input signals indicating the last anomaly to occur since a system reset operation. The coding circuit also includes a second portion for coding the first logic input signals. The second portion includes a sequential logic network to receive the first logic input signals and at least one second logic signal indicating the current operating phase of the driver. The second portion provides, as a function of the first and second logic signals, a stable internal state to determine the output information in the form of an N bit coded word.

Abstract: An ignition timing device for timing an engine having a timing port includes a sensor securable in the timing port to provide a timing mark signal. An ignition sensor is adapted to provide an ignition signal. A comparator receives the timing mark signal and the ignition signal. The comparator provides an output signal indicative of substantial simultaneous occurrence of timing mark signal and the ignition signal. An indicator receives the output signal and is operable as a function thereof.

Abstract: A sensor tester for testing multiple vehicle sensors is provided comprising: a circuit for testing a vehicle piezoelectric knock sensor; a circuit for testing a vehicle speed sensor; and a circuit for testing ignition coils. The circuit for testing piezoelectric knock sensors comprises: an integrated circuit electrically connectable to a power source, the integrated circuit having a multiple step voltage divider, a connector for connecting the integrated circuit to the knock sensor; and a plurality of light emitting diodes electrically connected to the voltage divider of the integrated circuit.

Abstract: A device for diagnosing the state of health of an ignition system is provided, where the system includes at least one spark producing channel comprising an exciter, output circuit and igniter plug. The device provides a diagnosis of the state of health for both the exciter and igniter plug by monitoring the high energy pulses at the output of the exciter. By monitoring the ignition system at an intermediate point in the system such as the output of the exciter, the sensor and electronics of the device may be completely contained within the electronic environment of the exciter, thereby avoiding any need for attaching sensors at the output of the system adjacent to the igniter plug in order to diagnose the plug's state of health. As an alternative to the device being built into the ignition system, it can be incorporated into automatic test equipment that produces high energy pulses for delivery to an igniter plug to be tested.

Abstract: An automotive electronic circuit analyzer that plugs into an automobile's electronic control module is disclosed. The disclosed analyzer includes positive and negative load sensing cells each having a series resistor coupled to an ECM load via the ECM connector and having an LED transistor for conducting current when the ratio between the load and the series resistor exceeds a predetermined value. A regulated power circuit for sinking current from the positive load sensing cells and for supplying current to the negative load sensing cells includes a timing circuit for controlling the active power pulse width so that the LEDs are illuminated with high frequency, short duration power pulses to indicate a shorted load.

Abstract: A method for testing an electronic ignition control module utilizes the steps of: placing the electronic ignition control module in electrical communication with an electronic ignition control module tester; the tester identifying the electronic ignition control module in electrical communication therewith so as to determine the type thereof; the tester performing testing of the electronic ignition control module, the particular tests performed being dependent upon the particular electronic ignition control module type being tester; the tester indicating pass/fail condition of the electronic ignition control module. Having the tester identify the electronic ignition control module type and perform testing which depends upon the particular electronic ignition control module type being tested eliminates the need for a user to define the tests to be performed.

Abstract: A device for diagnosing the state of health of an ignition system is provided, where the system includes at least one spark producing channel comprising an exciter, output circuit and igniter plug. The device provides a diagnosis of the state of health for both the exciter and igniter plug by monitoring the high energy pulses at the output of the exciter. By monitoring the ignition system at an intermediate point in the system such as the output of the exciter, the sensor and electronics of the device may be completely contained within the electronic environment of the exciter, thereby avoiding any need for attaching sensors at the output of the system adjacent to the igniter plug in order to diagnose the plug's state of health. As an alternative to the device being built into the ignition system, it can be incorporated into automatic test equipment that produces high energy pulses for delivery to an igniter plug to be tested.

Abstract: An apparatus for identifying the power stroke of a particular cylinder in a multi-cylinder engine which utilizes a wasted spark electronic distributorless ignition system but lacks a camshaft driven cylinder identification sensor, wherein a single sensor can be placed in a coil pack adjacent to and substantially equidistant from the ignition coil towers. The sensor will produce a signal reflecting the difference in voltage drops between corresponding pairs of spark plugs who share the same coil and which utilizes this signal to determine the power stroke of individual cylinders to produce a resulting synthetic cylinder identification signal. This apparatus can further be used as a permanent on-board sensor, thereby negating the need for a separate camshaft driven sensor, to determine the cylinder identification.

Abstract: A multi-test, hand-held instrument and method for testing manifold absolute pressure (MAP) and mass air flow (MAF) sensors includes a housing enclosing a battery and an electrical circuit. The electrical circuit can test d.c. voltage output signals and frequency output signals from MAP/MAF sensors and can test continuity and battery strength. Electrical leads extend outwardly from the housing and are connectable to the sensor being tested. A pair of light indicators, comprising LEDs and resistors connected in parallel, are selectively illuminated to allow the test instrument to be used to test both MAP and MAF sensors, and to test these components on different makes and models of vehicles.

Abstract: A plurality of sensors, such as a door handle lift switch, a headlight switch, and an ignition switch, are normally provided in an automotive electrical system. A master microcontroller normally is coupled to each of these sensors for receiving a signal therefrom and responsive thereto generating a corresponding controller signal. Power drivers, each operatively coupled to the master controller, normally are provided for energizing and powering loads coupled thereto, with each load being either an indicator or actuator that is operated responsive to its corresponding sensor. The self-diagnostic method includes the steps of mechanically actuating a selected one of the sensors, and then electrically actuating a first confirming indicator, such as an audible chime, indicative of the master controller receiving and successfully processing the corresponding sensing signal.

Abstract: A multi-test, hand-held instrument and method for testing engine sensors and ignition modules includes a housing enclosing a battery and an electrical circuit. The electrical circuit includes a first test circuit electrically interconnected with said battery for testing potentiometer-type, temperature-type and Hall effect type sensors and ignition modules, a second test circuit electrically interconnected with the battery for testing oxygen, reluctance and knock sensors, and a third test circuit for testing the battery in the instrument. A first switch selects between the first or second test circuits, while a second switch selects between a component testing mode and a battery testing mode. Electrical leads extend outwardly from the housing and are connectable to the engine component being tested.

Abstract: Monitoring apparatus is provided for the ignition system of an internal combustion engine such as is provided in a motor vehicle, which is capable of detecting a variety of malfunctions of ignition under a variety of engine operating ranges, so that the catalyst used in the exhaust system of the engine can be protected by setting lambda=0 and/or cutting off fuel injection to an inoperative cylinder, in as many instances of malfunction as possible. Various methods of monitoring are available and are correlated for selection in accordance with the different operating ranges of the engine. The ignition spark duration and the ignition discharge voltage are measured for individual sparks on the primary side of an ignition coil and are compared with limit values for correct ignition, these limit values being selected from a memory in accordance with the particular range of operating conditions in which the engine is operating.

Abstract: An input protection circuit protects a multiplexer used in an automotive breakout box for coupling to an electronic control module (ECM) of an automotive vehicle. The input protection circuit includes resistors connected between the input and the multiplexer and a negative feedback amplifier connected to the output of the multiplexer. The negative feedback amplifier provides a virtual ground. Additionally, the inputs to the multiplexer are clamped to within one diode forward voltage drop of electrical ground by diode pairs.

Abstract: An auto diagnostic apparatus having jawed, needle-toothed clips for connection to variable output wires of engine sensors adjacent to the sensors, and a processor which converts the output voltages to output values in reader friendly units understandable to the auto technician, and which stores and continuously updates the minimum and maximum output values for diagnosing intermittent or periodically interrupted electrical current. The needle-toothed clips establish an electrical connection to the variable output sensor wire without damaging the insulation or integrity of the sensor wire.

Abstract: An automated test system makes voltage and resistance measurements. The breakout cable is connected between the vehicle electronic control module and the vehicle sensors and controls. Resistance measurements are made between a selected pair of connector pins of the breakout cable by connecting a current loop (which includes a power supply and a known resistance) through a first multiplexing circuit to the selected pair of pins. A voltage measuring circuit measures voltage across the known resistance and between the pair of pins. The voltage measuring circuit includes a second multiplexing circuit and a voltmeter. The second multiplexing circuit receives inputs from the various pins, as well as from opposite sides of the known resistance in the current loop. The second multiplexing circuit provides its output to the voltmeter for measurement. By measuring the voltage across the known resistance, and the voltage between the selected pair of pins, the resistance between the two pins can be derived.

Abstract: An engine analyzer for an internal combustion engine includes an analog-to-digital (A/D) converter which digitizes an analog input waveform representing, for example, a secondary or primary voltage waveform of the ignition coil of the internal combustion engine. The sampling rate of the analog digital converter is determined by dividing the waveform time period by the desired number of samples. An adjustment factor C is used to provide a buffer period during the sampling period of the waveform. A display for displaying the waveform has a buffer region which corresponds to the buffer period. Thus, a variation in the speed of the engine which causes the engine to slow down and extends the period of the engine waveform does not cause a loss of data collected from the waveform because the buffer period provides a margin of error.

Abstract: A timing analyzer for engine diagnostic testing includes a variable sensitivity knob for testing ignition timing for both a conventional four stroke engine and a DIS four stroke engine. The timing analyzer has a pickup which is adapted to be placed around a lead from a spark plug in the engine. During spark plug firing, a current spike appears in the spark plug lead. The timing analyzer is adapted to be triggered when a current spike above a selected threshold level is detected. When the timing analyzer is triggered, a pulse of light is produced from the nose cone of the analyzer. During engine operation, the spark plugs are continuously being fired, which creates a strobe light effect from the analyzer. The timing analyzer is aimed at timing marks on the engine block, and at a single mark on the rotating flywheel, which permit the engine to be properly timed.

Abstract: The voltage developed by a primary winding of an ignition coil is supplied to a voltage divider for furnishing an analog signal of reduced amplitude for evaluation on an analog basis, which reduced amplitude analog signal is averaged by a capacitor connected between the voltage divider tap and ground. The capacitor eliminates the undesired effect of voltage spikes, but is not large enough to interfere with the measurement of voltages exceeding the ignition-initiating primary winding voltage value. The same reduced primary winding voltage is supplied through an input resistor to one input of a differential amplifier connected to operate as a switch having hysteresis and having a reference voltage applied to it such that the output will be the provision of a steady voltage having a duration corresponding to the spark discharge duration, for subsequent digital evaluation.

Abstract: A process for testing operational components in heaters, especially vehicle auxiliary heaters, in which the operational components are actuated and switched on sequentially, individually. Based on this, a corresponding evaluation is then performed. Further, a testing device for performing the process has a switching-on device with which the operational components can be started up, individually, on a sequential basis. From the process engineering viewpoint and from the device engineering viewpoint, further developments up to integration of the testing device in a heater control device are possible, and, optionally, for evaluation of the operational testing, external devices can also be used.

Abstract: A self-contained handheld peak ignition breakdown voltage probe locates faulty sparkplugs in an internal combustion engine. The probe has a novel dual-polarity detection system suitable for all ignition systems, distributorless or distributor types. Each nanosecond peak breakdown ignition event is signalled by a high-intensity LED lamp lit for a fixed period of time. An adjustable calibrated threshold level provides precise control of acceptance level. Other problems such as cabling, plug gap, and relative compression may also be inferred. The simple arrangement of integrated circuits provides a novel and useful tool for locating ignition problems.

Abstract: A distributorless ignition interface unit for use with an engine analyzer for analyzing an internal combustion engine includes a processing circuit which responds to analog signals representing true and wasted firings for the cylinders of the engine under test to determine the number of cylinders of the engine and the polarity of the firing of each cylinder and to then characterize the engine by determining the order of the true and wasted firing signals produced during an engine cycle and for producing a parade pattern of true or wasted secondary signals for application to the engine analyzer.

Abstract: A fault diagnosis system is provided for vehicles having a pluarlity of automotive electonic devices which output fault diagnoses according to one of a plurality of output signal schemes disposed thereon. A vehicle-side connector includes pins for carrying signal lines for signals representing the results of the fault diagnoses output from the plurality of of electronic devices. The vehicle-side connector also includes at least one pin for carrying at least one control line for a signal designating a selected output signaling scheme to the electronic devices. One of a plurality of testers displays the results of the fault diagnoses on the basis of the signals transmitted from the respective electronic devices. Each tester has a tester-side connector which connects to the vehicle-side connector to connect the output signals from each of the electronic devices and the control signal for designating the selective signaling scheme.

Abstract: A test module incorporating a unique diagnostic circuit for monitoring the magnitude of electrical parameters existing between an electrical driver such as the electronic control module (ECM) of an automotive vehicle and an electrical load in the vehicle's electrical system. The circuit employs a visual indicator connected to a point adjacent the driver to provide a visual signal when the voltage at the point of connection lies within a predetermined range with respect to electrical ground. An additional visual indicator, separate from the first, is connected to a point adjacent to the electrical load, and provides a visual signal when the voltage at its point of connection lies within a predetermined range with respect to electrical ground. A third visual indicator is connected between the driver and load, and provides a visual signal in response to current flowing between the driver and load.

Abstract: An ignition coil primary winding signal processing system that is suitable for use with cathode ray tube based instruments used in the troubleshooting, diagnosing, and servicing of spark ignition internal combustion engines. A primary trigger signal gnerator (4) processes the waveform obtained from the primary winding of the ignition coil of an internal combustion engine, V.sub.S, and produces a logical signal, V.sub.L, which drives a bistable circuit. The bistable circuit includes a D flip-flop FF1 that produces a square wave trigger signal, V.sub.T, whose rising edge corresponds to the point in time of the ignition points break, or the equivalent occurs in an electronic or transistorized ignition system. A dwell angle-to-voltage converter (8) also processes the complex waveform obtained from the ignition coil primary winding of an internal combustion engine, V.sub.S, and produces a nonfluctuating waveform, V.sub.C4, that is compared to a reference voltage.

Abstract: A microprocessor controlled digital engine analyzer receives analog input signals from an engine being analyzed, engine parameter data entered via a keyboard, and function data, selecting one of several operating modes for the analyzer and which information is to be displayed, entered via the keyboard, and displays on a CRT screen the selected information such as cylinder firing order, RPM, Dwell, KV and DC volts, alphanumerically, information such as primary and secondary ignition and voltage, alternator and fuel injector information through the use of continuous waveform patterns, and additional information pertaining to Dwell, KV and Cylinder Shorting through the use of bar graphs.

Abstract: A method and apparatus for the operational state analysis of internal combustion engines with electrical ignition systems wherein, following any deviation from normal engine operation, the cause of the deviation is determined and localized in the engine. Provision is made first to ascertain with good time resolution a numerical value of speed by measuring the time interval between two consecutive ignition pulses of different cylinders and then to determine a second numerical value which includes both the count of the number of ignition pulses and the cylinder designation, both numerical values being stored in digital form over a substantial length of time. The engine speeds for the particular cylinders computed from those two numerical values being graphically displayed in the time sequence of the ignitions as an electronically generated stationary image.

Abstract: A semiautomated diagnostic apparatus primarily used with ignition systems on internal combustion engines is novel in that every firing is examined for peak breakdown voltage level in a synchronized sequential manner to create a display of abnormalities and sequence number identification. Normal conditions can also be displayed in sequence when desired. A variable input permits examining relative peak voltages for further user analysis. An acoustic alert is provided as is an RPM indication and novel realtime indication of spark advance angle. The system operates at any engine speed.

Abstract: A test module incorporating a unique diagnostic circuit for monitoring the magnitude of electrical parameters existing between an electrical driver such as the electronic control module (ECM) of an automotive vehicle and an electrical load in the vehicle's electrical system. The circuit employs a visual indicator connected to a point adjacent the driver to provide a visual signal when the voltage at the point of connection lies within a predetermined range with respect to electrical ground. An additional visual indicator, separate from the first, is connected to a point adjacent to the electrical load, and provides a visual signal when the voltage at its point of connection lies within a predetermined range with respect to electrical ground. A third visual indicator is connected between the driver and load, and provides a visual signal in response to current flowing between the driver and load.

Abstract: A polarity and continuity tester of simple construction identifies grounded and positive lead wires in an automobile and is also capable of confirming proper operation of high voltage spark wires, all with one simple circuit. A tri-color light emitting diode is included in the testing device, along with a ground wire, a tester battery, a resistor and a conductive point probe, all connected in series. When the ground wire is secured to ground in the automobile, the point probe when touched to grounded conductors will cause the light emitting diode to emit a first color such as green, with current flowing through the diode in a first direction under influence of the tester battery. When the point probe is touched to a hot lead above about 5 volts, the tester battery becomes merely a conductor, current flows in the opposite direction, and the light emitting diode emits a second color such as red.

Abstract: An improved diagnostic apparatus for internal combustion engines; indicating engine speed, and dwell angle; capable of selectively inhibiting the firing of individual cylinders, and having: All readings automatically adjusted for the number of cylinders in the engine being tested; indication of proper synchronization with the engine under test; derivation of all operating power from the ignition signal of the engine under test.

Abstract: An ignition system interface for interposing an automotive combustion engine having a computer controlled ignition with an engine test analyzer. The interface receives timing signals from the ignition computer and generates modified timing based on command from the engine analyzer. Modified timing signals are transmitted to the coil ignition module which fires the spark plugs of the engine. The analyzer may command a shorting of the cylinder which causes the interface to modify the timing at the appropriate time for inhibiting a selected cylinder from firing. Secondary signals from the spark plugs are received by the interface and converted to a proper voltage waveform for recognition by the engine analyzer. The cylinder No. 1 is monitored by the interface and converted to a proper waveform for transmission to the analyzer.

Abstract: The Ignition Performance Measuring Circut is intended for use with dual ignition systems, such as the dual-magneto ignition systems used on light aircraft. The circuit has a first and second channel. The first channel is dedicated to measuring the relative peak amplitude of amplitude difference signals, i.e. the algebraic difference between concurrent left and right conditioned ignition signals. Signal conditioning is performed by an input attenuator and a difference amplifier. The circuit operates without benefit of a positive synchronization. To any particular cylinder's ignition firing signals. The pilot of an aircraft using the invention circuit will be alerted to the presence of a degraded firing signal but will not be advised as to which cylinder or spark plug is contributing to the failure indication. The circuit has a peak detection network for selecting the largest amplitude difference signal from each series of firing signals.

Abstract: An alternator produces current that has an average component and a ripple component. The alternator testing apparatus produces one voltage representative of the magnitude of the peak-to-peak amplitude of the ripple component and a second voltage representative of the sum of the average component and the peak-to-peak amplitude of the ripple component. A series of comparators each have their signal inputs coupled to receive the first voltage and their control inputs coupled to a divider network which is in turn coupled to receive the second voltage. Indicators are coupled to the comparators.

Abstract: An engine analyzer for an internal combustion engine includes an analog-to-digital (A/D) converter which digitizes an analog electrical input waveform representing, for example, a secondary or primary voltage waveform of the ignition coil of the internal combustion engine. The digitized input waveform is stored in the form of digital data in a data mamory. Upon request by the operator of the apparatus, a microprocessor selects digital data stored, and supplies that digital data to a display, which displays a visual representation of the waveform based upon the selected digital data. The engine analyzer apparatus produces a constant width waveform regardless of engine RPM, by determining the period of the waveform to be stored, and then varying the sample rate at which the A/D converter samples the analog waveform and converts the sampled waveform to digital data. As a result, the number of data samples, and thus the width of the displayed waveform, is constant.

Abstract: An internal combustion engine analyzer is described which permits analysis to be performed by attaching one sensor to the engine circuit. Timing at idle, engine speed, plug firing parade, etc., can be performed with only one sensor connected to the engine. For more extensive testing wherein additional leads are used, for example, at both the primary and secondary of the engine ignition coil, circuitry is provided for automatically triggering from both primary and secondary input signals or either one if only one is present. The analyzer also contains circuitry that enhances its use with both standard and electronic ignition systems. This circuitry rejects the noise generated by ignition systems in the cylinder ignition signals representative of plug firing so as not to mistrigger, or fire more than once for each plug firing.

Abstract: A fault diagnosis system is provided for vehicles having a pluarlity of automotive electronic devices which output fault diagnoses according to one of a plurality of output signal schemes disposed thereon. A vehicle-side connector includes pins for carrying signal lines for signals representing the results of the fault diagnoses output from the plurality of of electronic devices. The vehicle-side connector also includes at least one pin for carrying at least one control line for a signal designating a selected output signaling scheme to the electronic devices. One of a plurality of testers displays the results of the fault diagnoses on the basis of the signals transmitted from the respective electronic devices. Each tester has a tester-side connector which connects to the vehicle-side connector to connect the output signals from each of the electronic devices and the control signal for designating the selective signaling scheme.