Rotary operating element for automobile heating or air-conditioning provides electrical signal representing rotation of manual operating element rotated through more than 360 degrees

摘要

The rotary operating element converts a mechanical rotation of a manual operating element into a corresponding electrical signal via a rotary potentiometer (42) with a signal-free rotation range having a slider contact (58) cooperating with an ohmic resistance element (52) in the form of an open ring concentric to the rotation shaft (48) of the slider contact. The rotation shaft is driven by the rotation of the operating element via an intermediate gearing , a detector determining location of the operating element relative to a number of sectors corresponding in number and angular size to the gearing ratio, the electrical signal defined by the potentiometer signal and the detector signal.