Device for driving a positioning element by means of a stepping motor

摘要

A device for driving a positioning element via a stepping motor is described. This device makes it possible to continue operating the stepping motor in conjunction with its use as an encoder during phases without electrical control, so that the position last reached under electrical control, with a zero-current change in the position, possibly as a result of manual operation of the positioning element that is rotationally or frictionally coupled with the motor rotor, is constantly updated so that the control electronics is informed at all times of the actual position from which the stepping motor is to be controlled electrically to assume a new position. The device not only permits eliminating indexing devices that are subject to wear, but also allows automatic return, for example of a positioning element to its previous starting position after it has been shifted or adjusted from by an outside influence. The device is usable in conjunction with an operating or adjusting element in a vehicle and in this regard is especially advantageously usable in conjunction with an adjusting element that functions as a manual operating element of the heating or air conditioning system.