Device, in particular a tachometer wheel, for contactless tapping of rotational speed or contact making in machines

摘要

When reed contacts are used to scan tachometer wheels, they are not as reliable as required with respect to the high operating sequences occurring in the measurement of rotational speed and speed in machines and motors, and in particular with respect to the necessary high number of make-break operations. The device is therefore constructed for scanning by means of Hall sensors or other semiconductor sensors (6) sensitive to magnetic fields in such a way that the strength (intensity) of the magnetic fields of the magnet poles (N or S) used for the scanning outweighs the strength of the magnetic fields of the magnet poles (S or N) not used. <IMAGE>