Rotational speed pick=up with interference suppression - provides threshold varying with pulse amplitude level with pulses over threshold recognised as useful

摘要

The pulses are generated by a pickup measuring a speed of a rotating element, and their amplit ude greatly varies. In order to suppress lower amplitude interference pulses, a threshold is provided, and pulses exceeding it are recognised as useful pulses and are processed. The threshold is variable with the pulse amplitude level. The rotating shaft (1) has a flat (2) which accommodates a peg (3) which does not project outside the circular outline of the shaft. A sensor (4) is placed close to the shaft.