Actuating element on the basis of a films switch for the operation of an electronically controlled electric device and method for the evaluation of the switching pulses triggered by the adjusting element

摘要

The aim of the invention is to improve a control element which is used to operate an electronically controlled electrical appliance, said control element being suitable for combining with digital circuits and operating on the basis of a membrane switch. To this end, a movable knob (14, 15, 16, 17) comprising elastic contact springs (19) on its lower side is arranged in an opening of a front plate (11), and a membrane switching element (13) comprising a base layer, an upper layer consisting of a deformable material, and an elastic spacer layer is provided. The base layer and the upper layer are provided with strip conductors on their opposing surfaces, said strip conductors comprising contact points at defined points of intersection. The inventive control element is provided with an integrated circuit which continuously scans the electrical connections of all contact points in quick succession and is always operative, even in standby mode, in addition to an electronic, non-volatile memory which is used to store information about the respective switching position of the knob.