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:
Dec. 17, 1991
Filed:
Sep. 23, 1988
Richard E George, Everett, WA (US);
John Fluke Mfg. Co., Inc., Everett, WA (US);
Abstract
An apparatus for and a method of measuring capacitance employs a charge measuring system. While a capacitive element, which may be an unknown capacitor, is charged completely to a predetermined voltage, a charge proportional to the capacitance of the capacitive element is accumulated on the feedback capacitor of an integrating operational amplifier. Thereafter, the charge is measured by measuring the time required to completely remove the charge from the feedback capacitor using the same predetermined voltage as a reference. In a preferred embodiment, the present invention is manifested as a capacitance measurement feature in a hand-held multimeter wherein a largely conventional dual-slope analog-to-digital converter is employed as the charge measuring system.