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. 12, 1985
Filed:
Mar. 23, 1983
Norbert Eilers, Hildesheim, DE;
Blaupunkt Werke GmbH, Hildesheim, DE;
Abstract
To monitor the operability of a radio receiver which has special recognition circuitry to recognize warning or emergency announcements, a modulation detector (11) is provided, sensing the change in degree of modulation of a region recognition (RR) signal, which changes its degree of modulation when an announcement recognition (AR) signal is radiated, the degree-of-modulation signal being stored in a memory (flip-flop 12), the output of which controls a transfer switch (6). The transfer switch transfers output from a muting stage (5) in the receiver, which is disabled upon detection of the AR frequency to a tone generator, for application to the amplifier of a warning tone if no change in the degree of modulation of the RR signal has been detected within a predetermined time period, as determined by a timing stage (15). A suitable timing interval is, for example, 24 hours. If such timing signals are received, the tone generator is not enabled, however.