Abstract: An internal combustion engine analyzer provides both data acquisition and data processing and includes an analog waveform analysis subsystem together with a general purpose background system wherein appropriate power distribution is provided for the system as a whole and peripheral equipment such as a printer, keyboard and an analog/digital CRT is also provided. The input signals to be analyzed are waveforms generally associated with internal combustion engines and peripheral equipment. Exemplary waveforms are the primary and secondary ignition waveforms. The waveforms are attenuated to reasonable levels and multiplexed to analog circuitry which serves to measure waveform magnitude at one or more sampling points along the length of the wave and to also measure the manner in which the characteristics of the waveform change. The analog measurements are digitized and coupled to a processor which in turn controls the operation of the analog circuitry.

Abstract: An off-the-car wheel unbalance measuring system has a rotationally driven wheel mounting shaft supported in a pedestal together with a pair of force transducers mounted in the pedestal adjacent to and spaced along the shaft. The force transducers are coupled mechanically to the shaft and provide periodic electrical output signals indicative of unbalance forces transmitted through the shaft when the shaft is driven rotationally. The angular position of the shaft is monitored with respect to an angular reference position at a predetermined number of angular increments during each full revolution of the shaft. The transducer output signals are converted in electrical circuitry within the system to digital form, and a multiplication operation is performed on the digitized signals at each angular increment using sine and cosine representative factors corresponding to that particular angular increment.