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:
May. 02, 1989
Filed:
Oct. 21, 1987
Arthur Kurz, Karlsbad-Langensteinbach, DE;
Engelbert Laufer, St. Georgen, DE;
Wilfried Rohde, Unterkirnach, DE;
Deutsche Thomson-Brandt GmbH, Villingen, DE;
Abstract
In a control loop for automatically adjusting variable-gain amplification, a sinusoidal signal with a frequency f.sub.o that is critical for the control loop is superimposed over a positioning parameter W. Two synchronous rectifiers S1 and S2 filter out the oscillation components of a control parameter x and of a control difference x.sub.d that contain frequency f.sub.o, and the components are compared in a comparator VL. A control and regulating circuit C continues to vary the variable-gain amplification at controls RG until the amplitudes of the oscillation components being compared in the comparator are equal. The variable-gain amplification is correct at that point. The variable-gain amplification can even be adjusted in a compact-disk player while the player is in operation.