Abstract: An alternator for a motor vehicle has a rectifier bridge with positive diodes which are received in holes formed in a thermally conductive sector, which is fixed to an end plate of the alternator casing and which constitutes a thermal dissipator for the rectifier bridge. The rectifier bridge further includes a second sector of thermally conductive material, which is fixed to the first sector over the holes in the latter in which the positive diodes are received.

Abstract: A mechanism for supplying power assistance to the steering column of a vehicle is arranged to operate in response to signals indicating that power assistance is required, and therefore has periods in which it is inoperative and periods in which it is operative, all while the vehicle is in motion. The mechanism comprises a motor driving a speed reducing mechanism which is coupled to the steering column. The mechanism includes an epicyclic gear train, the planet wheel carrier of which is fitted around the steering column, the epicyclic gear train being driven by the power assistance motor. The outer crown of the epicyclic gear train is mounted so as to be free to rotate about the steering column, but when power assistance is required the outer crown is prevented from rotating by means of a releasable blocking or braking means actuated by an electro-magnet, thus causing the planet wheel carrier to rotate the steering column.

Abstract: A sensor for measuring an angle of rotation, and in particular the instantaneous angle of rotation of a rotatable member such as a steering column of a motor vehicle, is especially applicable in a power steering mechanism for a motor vehicle and includes a first wheel, the movement of which serves for measuring the angle of rotation and its direction. The sensor further includes a second wheel which is mechanically linked with but movable relative to the first wheel, the displacement of the second wheel being an indication of the number of rotations effected about an axis by the first wheel, and/or an indication of the direction of the rotation.