Abstract: An interface for coupling an engine analyzer to an engine having a distributorless ignition system includes a pair of pickup clamps for coupling signals from respective groups of spark plug wires. A logic cell array is supplied with spark plug secondary voltage polarity and pattern information, corresponding to an engine under test from a ROM. The technician is instructed as to which wires to place in each clamp. A semiconductor input switch is controlled by the logic cell array to sort the secondary voltages from the pickup clamps according to polarity. The real and the wasted sparks are then determined based upon the magnitude of the signals from the input switch. The apparatus permits a "rapid test" (of secondary voltages only) by developing a pseudo primary clock from the pickup clamp signals. A CPU in the interface is controllable by an external computer or by an operator keypad.

Abstract: An interface for coupling an engine analyzer to an engine having a distributorless ignition system includes a pair of pickup clamps for coupling signals from respective groups of spark plug wires. A logic cell array is supplied with spark plug secondary voltage polarity and pattern information, corresponding to an engine under test from a ROM. The technician is instructed as to which wires to place in each clamp. A semiconductor input switch is controlled by the logic cell array to sort the secondary voltages from the pickup clamps according to polarity. The real and the wasted sparks are then determined based upon the magnitude of the signals from the input switch. The apparatus permits a "rapid test" (of secondary voltages only) by developing a pseudo #1 primary clock from the pickup clamp signals. A CPU in the interface is controllable by an external computer or by an operator keypad.

Abstract: A method of scaling data between memories of different horizontal sizes by calculating an increment expressed as an integer and a fraction relating the horizontal memory sizes, multiplying the fraction by the dynamic range of a fraction portion counter, and successively adding the integer portion in an integer portion counter and the fraction portion in the fraction portion counter, with a carry to the integer portion counter when the fraction portion counter overflows. The corresponding points in the memories are selected based upon the total count in the integer portion counter.

Abstract: A method and apparatus of developing a stabilized power firing event signal for a cylinder in a wasted spark ignition system having pairs of complementarily connected cylinders, each with a spark plug connected to an opposite end of an independent ignition coil. The first and second firing event signals are developed for each spark plug upon firing of the ignition coil. The first and second signals are combined with like polarity in a summation circuit for eliminating common mode signal portions. The combined signal, which is now stabilized and accurately indicates spark duration, is used for capturing secondary ignition data and may be visually displayed for analysis.

Abstract: An engine analyzer includes an A/D converter for sampling analog data from an engine under test and developing digital data consisting of 11 magnitude bits and a sign bit. Four flag bits are added to make a digital word of sixteen bits with the four added bits being equal to the sign bit. Flags are set by making their bit value opposite to that of the sign bit. The sixteen bit words are stored in a RAM memory and the presence of the flags enables ready identification and retrieval of the data.

Abstract: An IBM-compatible computer based engine analyzer includes a RAM memory in a ROM cartridge location. A data acquisition system operates substantially independently of the system microprocessor to acquire engine test signals, convert them to digital form and store them via a register in the RAM memory. The system microprocessor has access to the RAM memory via a buffer for reading and changing the data therein. Control logic regulates access to the RAM memory by the A/D converter and the system microprocessor by controlling operation of the register and the buffer.

Abstract: A computerized emissions tester determines concentrations of HC, CO, and CO2 in exhaust emissions. An IR test bench assembly develops an analog voltage representative of the concentration of a particular gas in a sample gas of known concentration. Data related to calibration pressure, voltage offset and voltage gain are stored in non-volatile memory EEPROM. Algorithms relating voltage and concentration of the particular gases are included in software. The pressure of an exhaust emission is compared with the calibration pressure data in memory and a correction is applied to the tester output. The data relating to the voltage offset and gain factor are also used to compensate the tester output.

Abstract: The plural source arbitration system relates generally to communications systems for linking peripheral devices to a computer. Specifically, the arbitration system allows an external keyboard and a remote control device to be intercoupled to the keyboard slot of a computer and carry out communications without confusion.

Abstract: A method of determining the cylinder #1 power firing event in a wasted spark ignition system comprises developing a first signal comprising the integration of all power firing event signals, a second signal comprises the integration of all wasted firing event signals and comparing the amplitudes of the two signals to determine which represents the power firing events. The firing event signals are sorted for integration based upon knowledge of the polarity of spark plug firings, the cylinder firing order and the occurrence of a #1 cylinder firing event signal.

Abstract: A system for analyzing a diesel engine and transmitting data regarding faults within the diesel engine. Many diesel engines include glow plugs. The electrical characteristics of glow plugs are related to temperatures within the diesel engine which, in turn, are related to the operational characteristics of the diesel engine. The system measures the electrical characteristics of a glow plug, or other sensors, to determine attributes of the diesel engine and responsively provide a display representative of the operational characteristics.

Abstract: An automatic gain control circuit for driving a low mass infrared source used in an automotive exhaust gas emissions analyzer. A reference spectrum of radiant energy is monitored, demodulated and converted to an error signal to maintain the source at a constant energy output.

Abstract: A pair of operational amplifiers, one of which having a photoresistor feedback connecting the output of the amplifier to its inverting input. The non-inverting input of the last named amplifier being provided with a voltage developed by the second operational amplifier. The second amplifier serves to control the output of the first amplifier in accordance with changes in the output.

Abstract: An apparatus and method for dynamic testing of a rotary movement-electrical signal transducer system, such as found in an automotive anti-blocking system.

Abstract: An improved positioning pin assembly for a tire changing machine is disclosed, including a positioning pin operable in an adjustable latched state and an extended, adjustable biased state.

Abstract: An improved means for adjustably securing a bead-loosening shoe to its drive cylinder is disclosed. The securing means includes a channel shaped tube, secured to the cylinder, and a mating connector, secured to the shoe. A pair of locking apertures in the connector are selectively aligned with a pair of adjustment apertures in the channel shaped tube to set the stop position of the shoe at the full extension point of the cylinder.