Abstract

A device for the non-contact control of a sanitary fitting comprises in an emitting/receiving unit, in addition to an emitter and a receiver and their associated detection circuit as is known, a second receiver which can be reached directly by the radiation emitted by the emitter, and with which a second detection circuit is associated. In an initialization mode in front of a stationary reflector, the operating voltage of the emitter or the amplification of the detection circuits is continuously increased by a control unit until the desired sensitivity is reached. The values of representative voltages at which the two detection circuits are triggered are stored in respective stores. The quotient of these two values is put into a third store. In an adjusting mode, which is executed at set time intervals, the control unit continuously increases the operating voltage of the emitter, or the amplification of the detection circuits, and finds the value of the representative voltage at which the second detection circuit releases an output signal. This value is passed, together with the quotient stored in the third store, to a multiplier. The output signal of the latter is representative of a desired operating voltage of the emitter or amplification of the detection circuits, which is finally set by a microprocessor.