Measuring and testing – Speed – velocity – or acceleration
Patent
1982-09-27
1984-06-05
Gill, James J.
Measuring and testing
Speed, velocity, or acceleration
73506, 73518, 324160, G01P 302, G01P 342
Patent
active
044520794
ABSTRACT:
An acoustic tachometer for diesel engines includes a microphone which is responsive to the sounds generated by the engine combustion occurrences. The microphone signal is passed through a band-pass filter having a variable center frequency which is determined by a control signal from a sweep generator. The control signal has a known relationship to the operating speed of the engine. As the band-pass filter is swept through its frequency spectrum, a peak detector identifies the signals of maximum amplitude, which occur at the fundamental frequency of the combustion occurrences. The control signal voltage at the maximum amplitude and hence at the fundamental frequency is stored. At the end of each sweep, the stored control signal voltage is fed to an oscillator having a frequency which is dependent upon the stored control signal voltage, and is related to revolutions per minute (RPM). The output of the oscillator excites a counter-display circuit which displays the operating speed in RPM. In an alternate embodiment, the stored control signal voltage is connected to a second band-pass filter having a variable center frequency which is dependent upon the stored control signal voltage. The microphone signal is fed through the second filter, which passes only the fundamental frequency to a clipper and phase locked loop, from which is driven a counter and digital display showing RPM. Error detection circuitry alerts the operator if the sound to the microphone is inadequate or excessive for accurate measurement.
REFERENCES:
patent: 2174176 (1936-09-01), Journeaux et al.
patent: 2425811 (1942-06-01), Kent
patent: 2679629 (1950-03-01), Hellar, Jr.
patent: 3029385 (1959-08-01), Steinbrenner et al.
patent: 3289077 (1963-07-01), Miller
patent: 3400578 (1968-09-01), Frarey et al.
patent: 3815426 (1974-06-01), Rohner
patent: 4126045 (1978-11-01), Chou
patent: 4173896 (1979-11-01), Takama
patent: 4334422 (1982-06-01), Kawai et al.
Johnson and Hilburn, "Rapid Practical Designs of Active Filters", p. 141, (1975).
Cooper Industries Inc.
Gill James J.
LandOfFree
Acoustic tachometer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Acoustic tachometer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acoustic tachometer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1491845