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:
Sep. 09, 1997
Filed:
May. 22, 1996
Richard Joseph Ravas, Kokomo, IN (US);
Terrell Anderson, Carmel, IN (US);
Robert Keith Constable, Kokomo, IN (US);
Delco Electronics Corp., Kokomo, IN (US);
Abstract
The firing circuit of an inflatable restraint system is tested to verify operation of two FETs in series with a squib which are used to apply current to the squib. For the test the squib is biased to an intermediate voltage and each FET is turned on alone to apply battery or ground voltage to the squib. High and low voltage detectors sense the voltage excursion past respective thresholds to verify FET operation, and a logic circuit immediately turns off the FET to result in a very short FET on time. If a short is present before the FET is commanded on, a detector and the logic circuit prevents FET conduction to avoid firing or degrading the squib.