Abstract: An electrically operated control device and system for an appliance and method of operating the same are provided, the system comprising a power source of alternating electrical current that has a repeating voltage wave cycle and a repeating current wave cycle, a load for using the electrical current to provide an output of the load for the appliance, a relay having normally open contacts and a coil for closing the contacts only when the coil is energized, an electrical circuit for interconnecting the power source to the load through the contacts only when the contacts are closed, and a control unit for causing the coil to close the contacts substantially at a certain point on the voltage wave cycle each time the relay coil closes the contacts from the open condition thereof whereby the current flow through the contacts at each closing thereof is at substantially a desired level thereof.

Abstract: A rotary switch construction and method of making the same are provided, the switch construction comprising a surface unit having a substantially circular electrically conductive code pattern thereon, an electrically conductive wiper contact unit cooperating with the surface unit for making contact with a selected part of the pattern, and a rotary selector operatively associated with the units for selecting the desired part of the pattern that is to be contacted by the wiper contact unit, the wiper contact unit comprising a first pair of electrically connected wiper contacts disposed to respectively contact the pattern on a first substantially circular path thereof at points thereon that are disposed approximately 180.degree. from each other.

Abstract: An electrically operated control device and system for a microwave oven and method of making the same are provided, the device comprising a microprocessor for operating the power unit of the oven at various selected levels thereof, and a selector unit electrically interconnected to the microprocessor for selecting the desired power level that the microprocessor is to operate the power unit, the selector unit comprising a rotary switch that is electrically interconnected to the microprocessor in such a manner that the selector unit has a set sequence of the selection levels as the selector unit is rotated in one direction from a beginning position thereof to an ending position thereof, the beginning position being the position where the selector unit was last set for a previously desired power level setting of the microprocessor.

Abstract: A membrane keyboard construction and method of making the same are provided, the membrane keyboard construction comprising two circuit layers, a spacer disposed and secured between the circuit layers and having an opening passing therethrough to permit the circuit layers to be pressed together in the opening and thereby provide a switching function, a face plate, and an adhesive layer disposed between the face plate and one of the circuit layers and securing the face plate to the one circuit layer, the adhesive layer having a passage therein and leading from an area thereof that is aligned in superimposed relation with the opening to the exterior of the construction to vent that area thereof. The area is isolated from the opening by the one circuit layer and is vented by the passage to tend to enhance tactile feel and avoid false switch closure of the opening by tending to prevent entrapment of air bubbles in the area.

Abstract: A supervised start system for microprocessor based appliance controls and effective to prevent unwanted start operation of the associated appliance due to failure of a critical component of the starting system. The starting system requires a mechanical operation to effect starting of the associated appliance and the system tests all critical components thereof and failure of one component thereof will either render the associated appliance inoperative or cause an obvious but safe malfunction of the associated appliance.

Abstract: A rotary switch construction and method of making the same are provided, the switch construction comprising a surface unit having a substantially circular electrically conductive code pattern thereon, and electrically conductive wiper contact unit cooperating with the surface unit for making contact with a selected part of the pattern, and a rotary selector operatively associated with the units for selecting the desired part of the pattern that is to be contacted by the wiper contact unit, the wiper contact unit comprising a first pair of electrically connected wiper contacts disposed to respectively contact the pattern on a first substantially circular path thereof at points thereon that are disposed approximately 180.degree. from each other.

Abstract: A supervisory control system for microprocessor based appliance controls, the supervisory control system incorporating means for detecting dynamic failure of a microprocessor incorporated in the appliance control, means for disabling the high energy circuits in the associated appliance if the microprocessor is not operating in a normal mode and switch means requiring a physical or mechanical operation to enable energization of the high energy circuits of the associated appliance whereby the high energy circuits of the associated appliance are disabled unless at least two predetermined criteria are met.

Abstract: A membrane keyboard construction is provided and comprises two circuit layers, a spacer disposed and secured between the circuit layers and having an opening passing therethrough to permit the circuit layers to be pressed together in the opening and thereby provide a switching function, a face plate, and an adhesive layer disposed between the face plate and one of the circuit layers and securing the face plate to the one circuit layer, the adhesive layer having a passage therein and leading from an area thereof that is aligned in superimposed relation with the opening to the exterior of the construction to vent that area thereof. The area is isolated from the opening by the one circuit layer and is vented by the passage to tend to enhance tactile feel and avoid false switch closure of the opening by tending to prevent entrapment of air bubbles in the area.

Abstract: A solid state rotary entry control system for controlling appliances such as microwave ovens, dishwashers, washing machines, television sets and other appliances, the control system incorporating a first rotary entry means utilizing the angular displacement of a rotary switch to increment and decrement data, such as desired time, temperature or other data into a microprocessor based appliance control, the control system also incorporating a second rotary entry means for selecting, for example, a desired power level, such as a desired microwave oven magnetron power level, and also providing a power level bar graph display indicative of the power level selected by the user thereof.