Abstract: An automatic washing machine having an automatic washing liquid level control system including an ultrasonic apparatus for detecting the height of the clothes load in the washing machine and generating a signal representative of the clothes height, a control panel means for allowing user selection of the agitator speed, and means for generating a signal representative of the desired agitator speed. A control unit is provided including a fuzzy control which performs fuzzy inference on the basis of the signal representative of the clothes height and the signal representative of the agitator speed such that the optimum washing liquid level is achieved. In particular, membership functions according to fuzzy theory are defined for the clothes height and the agitator speed. Rules are defined for the height and agitator speed conditions such as for very high clothes height and low agitator speed, or medium high clothes height and high agitator speed, and so on.

Abstract: A water temperature control system for achieving one of a plurality of wash water temperatures for a washing machine having a hot water valve, a cold water valve and an inlet conduit for carrying a combined supply of water from the hot and cold water valves to a wash bath. If a WARM FILL option is selected by the user, the cold water valve is continuously energized thereby maintaining the valve in an open condition and a normally closed temperature responsive switch is connected in series with the hot water valve. The normally closed temperature responsive switch has a predetermined temperature set point and is located on the inlet conduit. The normally closed temperature responsive switch operates to cycle the hot water valve on and off to control the inlet wash water temperature at or below the first preselected set point. If a HOT FILL option is selected, the hot water valve is continuously energized and a normally open temperature responsive switch is connected in series with the cold water valve.