Sensor for indexing angle of rotation e.g. of steering column

摘要

The sensor for indexing the angle turned through by e.g. a steering column has a central boss (2) with integral rotor which can rotate with respect to a stator disc (6) having concentric tracks forming a variable resistor with the rotor contacts (3,4) to indicate clock/anticlockwise rotation. The sensor's range is extended to quantify up to 2.5 revs of the boss (2) in either direction by a toothed (24) star-wheel (22) which is advanced incrementally by the cam profile of a further disc (21) keyed to the boss (2). A sequential track (not shown) swept by a contact on the star-wheel (22) provides positional signals via conductors to the individual A-D inputs of a CPU (not shown) to give a high resolution index of rotation.