Contactless magnetic signal transfer from rotating shaft - using rotating coils and static stray field sensor in one of two variants esp. suitable for periodic or non-periodic signals respectively

摘要

A contactless method of magnetically transferring signals from a rotating shaft using rotating coils and a static sensor can involve one of two variants. One variant is partic. suitable for lock-in amplification in the case of periodic signals whose frequency can, but need not, coincide with the rotation frequency. The second variant of contactless, double astatised magnetic signal transfer is partic. suitable for lock-in amplification of non-periodic, constant or slowly varying weak and very weak electrical signals. USE/ADVANTAGE - For analoque, high resolution, astatised and distortionless measurement of very small direct and alternating electrical signals down to nanoampere or considerably lower than nanovolt region.