Whirlpool Corporation

Robert R Williams

Ronald W Holling

Edward L Thies

Raveendran Vaidhyanathan

Michael A Dirlam

Richard E Sinn

George Angelov

Bonifacio D Malana

Methods and system consistent with the present invention provide an appliance having inlet valves connected to respective supply lines with a control system that senses a temperature of a fluid supplied by a first of the supply lines, associates the first inlet valve connected to the first supply line with one of a plurality of predetermined temperature ranges, one of which includes the sensed temperature of the fluid in first supply line, and activates the first inlet valve upon a request by the appliance for a fluid in the one predetermined temperature range.

Electronic labeling of hot and cold fluid supply lines for an appliance

A fail-safe control system for operating a power relay to energize an electrical load such as a resistive heating element in a cooking apparatus includes first and second driving transistors connected in series with the control winding of the power relay and a source of power. A logic circuit, such as a microcomputer, produces pulses having specified characteristics at a single output port in order to energize the control winding. A circuit interconnecting the output port of the logic circuit with the driving transistors includes a first branch connected with the first transistor and a second branch connected with the second transistor. The first branch of the circuit includes an operational amplifier connected by a capacitor with the logic circuit output port in a manner that the first branch will drive the first transistor for a sufficiently long period of time initially in order to energize the relay control winding and cause the power relay to pull in. Thereafter, the first branch will only drive the first transistor if presented with pulses of much shorter duration; however, the shorter-duration pulses are capable of holding in the power relay. The second branch includes an operational amplifier connected directly with the logic circuit output port to apply all pulses produced at the output port to the second driving transistor.

Fail-safe relay drive system for cooking apparatus

The present invention is a fault detecting membrane potentiometer keyswitch. The keyswitch includes circuitry for providing a reference voltage signal when not activated, so that a faulty switch can be determined by absence of a reference voltage signal. Specifically, the wiper of the membrane potentiometer keyswitch is coupled to the resistive element of the keyswitch intermediate a sensing portion and a reference portion. With this arrangement, as long as the keyswitch is inoperative, the reference portion provides a reference voltage signal which is distinguishable from any of the setting voltage signals, and also distinguishable from a grounded condition. When a setting signal is observed, a timer is used to determined whether the setting signal is a user entered setting signal or a short between the wiper and the resistive element.

Fault detecting membrane potentiometer switch

A keyboard switch assembly includes a thin, flexible, glass top layer forming a membrane. Disposed on an inner surface of the glass membrane is a first conductive layer forming an electrode. Disposed beneath the first conductive layer is an insulating layer or spacer having an aperture therein that defines a switch contact area. Beneath the spacer a rigid portion of the keyboard switch assembly is provided. The rigid portion of the keyboard switch assembly includes a rigid substrate with a conductive coating formed thereon to provide a second conductive layer or electrode disposed beneath the spacer. A flexible polymer layer may further be disposed between the rigid substrate and the second conductive layer to reduce point contact degradation in the keyboard switch assembly. Decorative paint layers may be formed on the inner surface of the glass membrane between the glass membrane and the first conductive layer. Alternatively, where the layers forming the keyboard switch assembly are transparent, a decorative paint layer may be disposed on an outer surface of the rigid substrate.

Glass membrane keyboard switch assembly for domestic appliance

An electric range having a self-cleaning oven utilizes a digital electronic microprocessor based oven temperature control system having multiple, redundant oven temperature sensing elements. The output signal from a first one of the multiple oven temperature sensing elements disposed in the cavity of the oven is used as a primary sensed bake temperature signal for controlling the temperature of the oven during its BAKE mode of operation and as a redundant or back-up sensed clean temperature signal for safely shutting down the oven during its CLEAN mode of operation in the event that the sensed oven temperature significantly exceeds the top of the clean temperature range. Correspondingly, the output signal of a second oven temperature sensing element is used as the primary sensed clean temperature signal for controlling the operation of the oven during its CLEAN mode of operation and as a redundant or back-up sensed bake temperature signal for safely shutting down the oven in the event that the sensed oven temperature during the BAKE mode of operation significantly exceeds the top of the bake temperature range. Oven temperature sensing proves associated with the above two temperature sensors may be individually mounted in separate housings in the oven cavity or may be mounted in a single sensor housing in the oven cavity where space or mounting considerations are particularly acute.

Self-cleaning oven temperature control with multiple redundant oven

A capacitive touch panel control provided with first and second conductive circuit pads on opposite faces of a thin dielectric sheet in the form of a film secured to a dielectric panel by adhesive. The panel is provided with a touch pad. The circuit pads are disposed so that at least a portion of each is in appositional facial registration with the touch pad and out of appositional facial registration with each other so as to provide a variable capacitance between the circuit pads as an incident of selective touching and non-touching of the touch pad by a user. The circuit pads may form a portion of a printed circuit on the film which further includes electrical conductors for making connection to associated apparatus. Ground conductors may be provided on the film adjacent the output voltage conductors of the circuit to reduce leakage between the circuit conductors. The provision of the circuit pads on opposite faces of the film permits electrically insulated crossover of the conductors for facilitated layout of the circuit.

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Lincoln, MI, United States of America

Robert R Williams