Method and circuitry for control of a sanitary mixer for cold and hot

Abstract

In a method for control of a sanitary mixer for cold and hot water, merely the actual temperature is continuously measured in the mixed water and compared to a preset temperature. At least two separate, time-varying regulating values, used for electromechanical adjustment both of the cold as well as of the hot water supply, are electronically derived from the difference between the set and actual temperature. A preset flow rate of the mixed water that is to be kept constant during temperature control is taken into account in the determination of the regulating values. Furthermore, partial flow rates for the cold water supply and hot water supply that are proportional to the regulating values can be determined from the time-varying regulating values. These are then used to continuously determine the instantaneous cumulative filling volume of the mixed water. As soon as a cumulative filling volume value equal to a preset cumulative filling volume is reached, the cold and hot water supplies can be shut off. In addition, a filling operation can be interrupted and resumed taking into account the filling volume drawn up to the interruption. In this way actuation of the cold and hot water valves is made possible via a simple temperature measurement while dispensing with the flow rate determination; in this case temperature, flow rate and/or filling volume can be preset.