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:
Jul. 09, 1996
Filed:
Aug. 10, 1994
Djahanyar Chahabadi, Hildesheim, DE;
Lothar Vogt, Hohenhameln, DE;
Blaupunkt-Werke GmbH, Hildesheim, DE;
Abstract
In a digital circuit which removes ignition noise from a multiplex signal in a radio receiver, especially in a car radio, the multiplex signal is supplied via a high-pass filter (3) and a squaring or absolute value determing circuit (4) as a digital signal with a sampling frequency that is a multiple of the frequency of the pilot tone. The high-pass filtered and squared or absolute value multiplex signal is compared to a short-time mean value of the high-pass filtered and squared (in absolute value) multiplex signal. A control signal S of predetermined duration is formed when deviations occur that are greater than a preset standard. The control signal S controls a correcting circuit in such a manner that sampling values of the multiplex signal occurring during the control signal are replaced with sampling values occurring during the previous period of the pilot tone, thereby masking the ignition noise.