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. 28, 1989
Filed:
Mar. 29, 1988
Applicant:
Inventor:
Peter Seibold, Diekholzen, DE;
Assignee:
Blaupunkt-Werke GmbH, Hildesheim, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340568 ; 307 / ; 340 63 ; 340691 ; 34082531 ; 34082532 ;
Abstract
To prevent overriding an electronic car radio theft disabling system by connecting an external battery to a car radio prior to theft thereof, the radio includes a measuring circuit (7, 7') measures the impedance of a connected accessory, for example a loudspeaker or loudspeaker system (8), and if the impedance of connected loudspeaker does not match the impedance stored in a memory (5) of the car radio, operation of the radio is inhibited until the appropriate code word--known only to the proper owner--is reinserted.