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:
Apr. 19, 1988
Filed:
Apr. 07, 1986
Walter Schmitt, Traunreut, DE;
Dr. Johannes Heidenhain GmbH, Traunreut, DE;
Abstract
A process and apparatus for use in digital length or angle measuring systems for regulating the keying ratio of at least one periodic electrical signal. A signal is produced, proportional to the desired keying ratio, and compared with the periodic electrical signal. A momentary difference signal is generated from the comparison. If the frequency of the periodic electrical signal is within a selectable frequency range, the momentary difference signal is applied to a correction circuit, which is circuited parallel to a storage unit. The correction circuit supplies a correction signal, based on the momentary difference signal, to a sum amplifier. The sum amplifier is operative to superpose the correction signal on the periodic electrical signal, thereby regulating the keying ratio of the periodic electrical signal. The storage unit is operative to store a signal proportional to the difference signal. If the frequency of the periodic electrical signal is outside the selectable frequency, the correction signal is derived from the contents of the storage unit.