Whirlpool Corporation

Ronald W Holling

Robert R Williams

Jerome D Huener

Patrick J Glotzbach

Larry J Manson

Julio C Moreira

Arne M Nystuen

Rosario Ciancimino

Donald R Vander Molen

Bonifacio D Malana

A motor controller for a single phase induction motor (SPIM), wherein the SPIM is driven by two windings, a line winding connected to the ac line and a control winding driven by the controller. The SPIM torque and hence the speed and direction is controlled by the voltage output of the controller for all speeds below the synchronous speed (set by ac line frequency). The controller adjusts the amplitude, the phase angle relative to the line winding, and the frequency of the voltage for the desired SPIM responses. The controller can also selectively switch power to the line winding for a different operating mode with both windings at below synchronous speed. Or, the controller can open the connection to the line winding after starting, and operate the SPIM via the control winding at any speed by adjusting the amplitude and frequency of the controller voltage.

Electric motor speed and direction controller and method

A cooking appliance or an electronic control for a cooking appliance and method of controlling the same including a remote control unit which has a built-in temperature sensor, positional switch and low-battery detection circuit is in two-way intermittent wireless communication with the appliance control unit of the present invention. The appliance control unit includes a switch means for controlling the heating elements of the cooking appliance wherein the switch means for each heating element includes two power switches connected in series and coupled with a redundancy detection circuit for the detection of a failure of one of the two power switches. Two-way communication between the two control units of the present invention is constantly monitored to ensure proper operation of the cooking appliance and to provide a mechanism to report errors to the user or to shut down the cooking appliance, as appropriate, soon after an error is detected. Mechanisms are also provided whereby the wireless communication means of the control units may be diagnosed to ensure the control units are properly communicating with each other.

Over temperature condition sensing method and apparatus for a domestic

The present invention is a cooking appliance or an electronic control for a cooking appliance and method of controlling the same. A remote control unit having a built-in temperature sensor, positional switch and low-battery detection circuit is in two-way intermittent wireless communication with the appliance control unit of the present invention. The appliance control unit includes a switch means for controlling the heating elements of the cooking appliance wherein the switch means for each heating element includes two power switches connected in series and coupled with a redundancy detection circuit for the detection of a failure of one of the two power switches. Two-way communication between the two control units of the present invention is constantly monitored to ensure proper operation of the cooking appliance and to provide a mechanism to report errors to the user or to shut down the cooking appliance, as appropriate, soon after an error is detected. Mechanisms are also provided whereby the wireless communication means of the control units may be diagnosed to ensure the control units are properly communicating with each other.

Diagnostic method and apparatus for a domestic appliance

A cooking appliance or an electronic control for a cooking appliance and a method of controlling the same including a remote control which has built-in temperature sensor, positional switch and low-battery detection circuit is in two-way intermittent wireless communication with the appliance control unit. The appliance control unit includes a switch means for controlling the heating elements of the cooking appliance wherein the switch means for each heating element includes two power switches connected in series and coupled with a redundancy detection circuit for the detection of a failure of one of the two power switches. Two-way communication between the two control units of the present invention is constantly monitored to ensure proper operation of the cooking appliance and to provide a mechanism to report errors to the user or to shut down the cooking appliance, as appropriate, soon after an error is detected. Mechanisms are also provided whereby the wireless communication means of the control units may be diagnosed to ensure the control unit are properly communicating with each other.

Fault detection method and apparatus for a domestic appliance

A cooking appliance or an electronic control for a cooking appliance or an electronic control for a cooking appliance and method of controlling the same includes a remote control unit having a built-in temperature sensor, positional switch and low-battery detection circuit is in two-way intermittent wireless communication with the appliance control unit. The appliance control unit includes a switch means for controlling the heating elements of the cooking appliance wherein the switch means for each heating element includes two power switches connected in series and coupled with a redundancy detection circuit for the detection of a failure of one of the two power switches. Two-way communication between the two control units of the present invention is constantly monitored to ensure proper operation of the cooking appliance and to provide a mechanism to report errors to the user or to shut down the cooking appliance, as appropriate, soon after an error is detected. Mechanisms are also provided whereby the wireless communication means of the control units may be diagnosed to ensure the control units are properly communicating with each other.

Remote control for a domestic 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 relay control for a cooking appliance having a heating element includes a sensor for detecting the occurrence of an arc upon a change of state of a relay coupled between the heating element and a power supply. Upon detecting an arc, the sensor provides a timing signal which is coupled to a microprocessor that controls the energization and deenergization of the relay. The microprocessor is responsive to the timing signal from the sensor to determine the time delay between the last energization/deenergization of the relay and the changing of the relay's state. From the time delay, the microprocessor determines a delay constant. Subsequently, the microprocessor energizes the relay at a time after the detection of a zero crossover point of the power supply signal, wherein the time is equal to the determined delay constant to cause the relay to change state at or slightly before a zero crossover point of the power supply signal. The sensor may take the form of an optical sensor mounted inside the housing of the relay or outside of the housing. Alternatively, the sensor may include an electromagnetic or RF pick-up coil for sensing an electromagnetic or RF signal in the radio frequency (RF) range radiated upon the generation of an arc. Alternatively, the sensor may be a vibration sensor, such as a piezoelectric transducer, capable of detecting vibrations associated with the opening or closing of the relay contacts.

Relay control apparatus

Relay control method and apparatus for a 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.

Growing community of inventors

Lincoln, MI, United States of America

Ronald W Holling