As we have seen, deceleration sensors have a very important role in the operation of airbags in the event of an accident, and there are various ways of installing and using them depending on the type of sensor being used.
First, we find mechanical sensors , which use a spring-controlled rotating roller, which in the event of a frontal collision will move forward, closing a grounded switch.
It is the mass itself that will indicate to the control unit the initial procedure for inflating the balloon, so in the installation the direction of the sensor is usually indicated with an arrow stamped on it.
There are also electronic sensors , which have 4 Wheatstone bridge resistors, which register the deformation of the plate where they are installed, sometimes caused by a metal mass attached to one end.
Finally, the electromagnetic sensor has a fixed magnet and a movable magnet, which generate an electromagnetic field capable of displacing the movable magnet in cases of sudden deceleration, which compresses a spring and closes a contact.
This closure informs the control unit of the deceleration, and this in turn relays it to the microprocessor.