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. 04, 1992
Filed:
Nov. 14, 1990
Leonard W Behr, Pontiac, MI (US);
Craig W White, Grosse Pointe, MI (US);
Automotive Systems Laboratory, Inc., Farmington Hills, MI (US);
Abstract
An air bag firing circuit comprises a firing path which includes redundant acceleration sensors, i.e., two sensors of like threshold connected in parallel. Each sensor comprises normally-open switch means operated by an inertial mass and shunted by a resistor. A battery maintains a known voltage across the firing path while a microprocessor checks the integrity of the firing path by periodically reading and comparing the voltages achieved at various points thereabout. The microprocessor further tests each sensor individually by electromagnetically biasing the sensor's inertial mass in a manner so as to close the switch means thereof while determining the effect of such testing on the voltages achieved about the firing path. Upon the detection of a sensor failure, the microprocessor electromagnetically biases the sensor's inertial mass in a manner so as to maintain the switch means thereof in its open position, whereby the malfunctioning sensor is functionally removed from the firing path without impairing the function of the other sensor connected in parallel therewith.