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:
Feb. 09, 1988
Filed:
Feb. 04, 1987
Manfred Kreuzer, Weiterstadt, DE;
Hottinger Baldwin Measurements, Inc., Framingham, MA (US);
Abstract
A measured voltage is converted into a digital value according to the follow-up principle. A compensation signal is added to the measuring signal so that the mean value of both signals becomes zero. The compensation signal is formed from at least two auxiliary compensation values which are each a square wave signal having a fixed frequency and a keying ratio which is adjustable independently of the other square wave voltage. The keying ratios are varied or adjusted so that the compensation signal compensates the measured signal. In order to achieve this the value deviating from zero of the sum of the measured signal and the compensation signal is integrated, converted into digital values, and supplied to a PI-or PID-control circuit which controls in a closed loop manner the keying ratios of the square wave signals. The I-value of the PI- or PID-control circuit serves as a measure of the measured voltage.