Fault detection device for occupant protective systems
First Claim
1. In a fault detection device for an occupant protective system for use in an automotive vehicle, said occupant protective system having a plurality of squibs, a power supply for supplying electric current to said squibs, a power supply switch connected to said power supply, and actuating means for generating a common signal for actuating said squibs to operate said system when said vehicle undergoes deceleration in excess of a predetermined value, said squibs being connected in parallel with each other with respect to said actuating means for causing at least a predetermined amount of electric current as said common signal to flow in parallel through said squibs,the improvement comprising:
- a squib circuit having said squibs;
at least one resistance connected to said squibs for allowing a slight amount of electric current which is smaller than said predetermined amount of electric current to flow through said squibs when said power supply switch is activated;
at least one unilateral conductive element connected to said squibs and said at least one resistance for normally causing said slight amount of electric current to flow in series through said squibs; and
a fault detection circuit for detecting a fault in any of said squibs at one time by comparing a potential at a predetermined point in said squib circuit with at least one predetermined reference voltage.
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Accused Products
Abstract
A fault detection device for an occupant protective system for use in an automotive vehicle, which has a plurality of squibs connected in parallel with each other. A common signal is generated for actuating the squibs to operate the system when the vehicle undergoes deceleration in excess of a predetermined value. A squib circuit has the squibs, at least one resistance connected to the squibs in such a manner that a slight amount of current flows through the squibs, and a unilateral conductive element connected to the squibs and the resistance in such a manner that the slight amount of current flows through the squibs in a predetermined single direction. A fault detection circuit detects a fault in any of the squibs based on a potential at a predetermined location in the squib circuit.
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Citations
8 Claims
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1. In a fault detection device for an occupant protective system for use in an automotive vehicle, said occupant protective system having a plurality of squibs, a power supply for supplying electric current to said squibs, a power supply switch connected to said power supply, and actuating means for generating a common signal for actuating said squibs to operate said system when said vehicle undergoes deceleration in excess of a predetermined value, said squibs being connected in parallel with each other with respect to said actuating means for causing at least a predetermined amount of electric current as said common signal to flow in parallel through said squibs,
the improvement comprising: -
a squib circuit having said squibs; at least one resistance connected to said squibs for allowing a slight amount of electric current which is smaller than said predetermined amount of electric current to flow through said squibs when said power supply switch is activated; at least one unilateral conductive element connected to said squibs and said at least one resistance for normally causing said slight amount of electric current to flow in series through said squibs; and a fault detection circuit for detecting a fault in any of said squibs at one time by comparing a potential at a predetermined point in said squib circuit with at least one predetermined reference voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification