| 摘要 |
PROBLEM TO BE SOLVED: To provide a malfunction alarming lamp lighting circuit for an air bag, allowing the lighting of a malfunction alarming lamp even when a wire harness is broken. SOLUTION: An air bag IC has a switching transistor TFET for detecting the malfunction of the air bag. The transistor is connected to a power supply and a ground potential and the lighting circuit for an alarming lamp L is connected to the power supply side of the transistor TFET via the wire harness so that the transistor is turned on to make the alarming lamp lit when the air bag is malfunctioned. The alarming lamp lighting circuit has a series circuit for a switching transistor Tr and the alarming lamp L and a series circuit for first-to-third resistances R1, R2, R3, connected in parallel between the power supply and the ground potential, and the base of the transistor connected between the first and second resistances, wherein a connection point between the second and third resistances is connected to the air bag IC via the wire harness.
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