Occupant safety is one of the most critical elements of the automobile design. As a result, safety systems continue to become more sophisticated in order to limit, and ultimately prevent, personal injury in the case of an accident
Seat Position Sensor
Occupant safety is one of the most critical elements of the automobile design. As a result, safety systems continue to become more sophisticated in order to limit, and ultimately prevent, personal injury in the case of an accident.
Seat position sensing is used in safety systems to determine the position of an occupant in relation to the steering wheel, preventing the air bags from deploying with excessive force.
The most common solution today incorporates two-wire, unipolar, Hall-effect switches to sense discrete seat position zones. The sensor must relay this information in the form of a digital output to the controller unit indicating a particular zone. This information must be correct at start up of the vehicle, so the sensor output must decode without any user action.
The seat track is typically a ferrous metal material capable of interrupting the magnetic field between the Hall-effect sensor and a magnet. The ferrous metal of the seat track passes between the switch and the magnet causing the switch to turn on or off, relaying seat position information to the controller unit. A change in the output state of the sensor indicates to the controller unit that the seat has passed into a particular zone.
Read More: http://www.allegromicro.com/en/Products/Design/vehicle_safety/index.asp
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