The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 08, 1989
Filed:
Jun. 30, 1988
Gordon W Shank, Portland, OR (US);
Tektronix, Inc., Beaverton, OR (US);
Abstract
An oscilloscope automatically measures an interval between first and second triggering events in a repetitive input signal. The oscilloscope includes A and B sweep circuits for generating event triggered 'A' and 'B' sweep ramps, respectively. The oscilloscope also includes two comparators. One comparator generates an 'A' indicating signal when the A sweep ramp reaches the level of a first adjustable reference signal. The other comparator generates a 'B' indicating signal when the B sweep ramp reaches the level of a second adjustable reference signal. The oscilloscope initially sets both sweep circuits to repetitively trigger on the first event and sets the first reference signal to a constant level. While monitoring relative timing of the A and B indicating signals, the oscilloscope iteratively adjusts the second reference signal to a 'first pass' level for which the A and B indicating signals are repetitively generated at substantially similar times. Thereafter, the B sweep ramp is set to repetitively trigger on the second triggering event while the A sweep ramp continues to repetitively trigger on the first triggering event. The oscilloscope then iteratively adjusts the second reference signal to a 'second pass' level at which the A and B indicating signals are again generated at substantially similar times. The difference between the first and second pass levels is proportional to, and therefore a measure of, the interval between the first and second trigger events.