Device for detecting the direction and change of rotational speed of a rotating element

摘要: Device for detecting the direction and change of rotational speed a rotating element. In one embodiment, pair phototransistors which are energized by light source according to an ordered sequence through disk formed opaque transparent sectors coupled The two controls, when switching on transistors enable discharge capacitors, charging with predetermined time constant in interval between discharges. control action first capacitance is however conditioned charge level reached other therefore both order energization frequency. If frequency lower than certain limit or not correct one, capacitor reaches higher reference value supplies indication signal accordingly.