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Air Bag Systems: Description and Operation





PURPOSE
The Supplementary Restraint System (SRS) further improves the protection afforded by the car's seat belts.

CONSTRUCTION
The system consists of two front sensors connected in parallel, a control module, and a steering wheel with gas generator and airbag. The airbag is mounted in the center of the steering wheel.

The belt tensioner on the passenger side is also connected to the system.

There is also a knee shield mounted on the steering column assembly which prevents submarining.

OPERATION
The system is activated when one of the two front sensors is subjected to a force corresponding to a frontal collision with a steel barrier at a speed of (25 km/h) 15 MPH. In a collision the airbag inflates and, together with the seat belt, prevents the driver from striking the steering wheel, dashboard and windshield.

The system is controlled by a control module. The front sensors transmit information to the control module which sends a current pulse to an electric detonator. The detonator sets off an explosive charge in a gas generator and causes the airbag to inflate.