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. 30, 1996
Filed:
Sep. 19, 1994
Jon Tourville, Colorado Springs, CO (US);
Christopher J Kemp, Monument, CO (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A circuit for determining the operability an airbag squib resistor. The circuit includes a current source, the squib resistor to be measured, a first resistor whose resistance is equal to the minimum acceptable resistance of the squib resistor, a second resistor whose resistance is equal to the maximum acceptable resistance of the squib resistor, a voltage-to-current converter, a capacitor, a comparator, and a microprocessor with a counter. A first switch connects the squib resistor and first and second resistors in series. A second switch couples the inputs of the voltage-to-current converter individually across the squib resistor and first and second resistors. As the second switch is coupled to the squib resistor, the first resistor or second resistor, a third switch is opened to initiate charging of the capacitor which is coupled to the output of the voltage-to-current converter. A time measurement is made of the time required for the capacitor to charge to a predetermined threshold voltage. The time measurement is made with the second switch in each of its three states. The time measurements are compared and the squib resistor is deemed inoperative if the time measurement for the squib resistor is not within the range established by the time measurements for the first resistor and the second resistor.