Capacitative accelerometer for triggering airbag in motor vehicle

摘要

The appts. comprises a seismic mass (24) restrained to move along one axis from a rest position to which it is returned by an elastic means such as a spring (18). The mass (24) carries a moving electrode (16) which forms a capacitor with a fixed electrode (14). An electronic circuit (12) allows measurement of the capacitance. Stops (20) limit movement of the seismic mass.The appts. is adjusted so that the characteristics of spring extension and electrostatic force make contact at least one point.