Whirlpool Corporation

Panasonic Holdings Corporation

Panasonic Corporation

Davide Guatta

Valeria Nocella

Mattia Rigo

Raffaele Paganini

Francesco Giordano

Alberto Morandotti

Henrik Mattfolk

Francesco Del Bello

Franco Brindani

Adriano Scaburri

Giovanni Dore

Paolo Sicher

Mariagrazia Dauria

Jutta Ziermaier

Mariagrazia D'Auria

Matteo Luciano Vanelli

An interrupting circuit () is configured to monitor for and detect a fault in a device () for generating a field of electromagnetic radiation (e-field) () from a radio frequency (RF) generator () configured to convert low voltage direct current (DC) into the e-field () for application to an article in the e-field (). If a fault is detected, the interrupting circuit () interrupts low voltage DC between an energy reserve () and the RF generator () within a predetermined time less than the time to dissipate energy stored in the energy reserve ().

Interrupting circuit for a radio frequency generator

An electromagnetic cooking device and method of controlling the same is provided herein. The cooking device includes a cavity in which a food load is placed and a plurality of RF feeds configured to introduce electromagnetic radiation into the cavity for heating the food load. A controller is provided and is configured to: (a) measure resonances in the cavity; (b) generate a resonance map resulting from the measured resonances; (c) conditionally repeat steps (a) and (b); (d) detect a melting state of the food load based on variations between the resonance maps; and (e) adjust a power level of the electromagnetic radiation in response to detection of the melting state.

Electromagnetic cooking device with automatic melt operation and method of controlling cooking in the electromagnetic cooking device

An electromagnetic cooking device and method of controlling the same is provided herein. The cooking device includes a cavity in which a liquid is placed and a plurality of RF feeds configured to introduce electromagnetic radiation into the cavity for heating the liquid. A controller is provided and is configured to analyze forward and backward power at the plurality of RF feeds to calculate efficiency; determine and monitor a coefficient of variation of the efficiency; detect a heating state in the liquid based on changes in the coefficient of variation; and adjust a power level of the electromagnetic radiation in response to detection of the heating state.

Electromagnetic cooking device with automatic boiling detection and method of controlling cooking in the electromagnetic cooking device

A method for analyzing a frequency response of a cooking device is disclosed. The method comprises controlling a plurality of RF signals within an operating range of the cooking device at plurality of phase shifts between a first RF signal and a second RF signal. A plurality of efficiencies of at least one reflection signal in the resonant cavity are measured in response to a plurality of RF feeds generated from the RF signals for the plurality of phase shifts. The frequency response of the resonant cavity is modeled with a numeric model and a plurality of interpolation parameters for the numeric model are calculated based on the plurality of measured efficiencies of the RF feeds. The frequency response of the cavity is estimated for the operating range of the cooking device based on the numeric model with the plurality of interpolation parameters.

System and method for analyzing a frequency response of an electromagnetic cooking device

An electromagnetic cooking device and method of controlling the same is provided herein. The cooking device has a cavity in which popcorn is placed and a plurality of RF feeds configured to introduce electromagnetic radiation into the cavity for popping the popcorn. A controller is provided and is configured to: analyze forward and backward power at the plurality of RF feeds to calculate efficiency; determine and monitor a coefficient of variation of the efficiency; detect a popping state of the popcorn based on changes in the coefficient of variation; and adjust a power level of the electromagnetic radiation in response to detection of the popping state.

Electromagnetic cooking device with automatic popcorn popping feature and method of controlling cooking in the electromagnetic device

A method of determining heating strategies for a cooking appliance () includes obtaining geometry dimensions, power values, and frequency values of the cooking appliance (), selecting a food item () and obtaining a food geometry, permittivity value, and initial temperature of the selected food item (). A heating pattern () for heating the selected food item () is estimated based on the food geometry, permittivity value, and initial temperature of the selected food item () and data indicative of the estimated heating pattern () is inputted to an operating control system () to achieve the estimated heating strategy.

Method and apparatus for determining heating strategies

A method for identifying a cooking level of a food load in an electromagnetic cooking device is disclosed. The method includes controlling a frequency and a phase of a first RF signal and a second RF signal and amplifying the first RF signal and the second RF signal thereby generating a first RF feed and a second RF feed. The method further includes emitting the first RF feed and the second RF feed into an enclosed cavity to heat a food load and measuring at least one reflection signal. The method further includes calculating a Q-factor for the enclosed cavity based on the reflection signal, monitoring the Q-factor, and identifying a change in the Q-factor exceeding a predetermined change threshold. In response to identifying the change exceeding the predetermined change threshold, a cooking level for the food load is identified.

System and method for detecting cooking level of food load

An electromagnetic cooking device is provided having a controller and a plurality of RF feeds configured to introduce electromagnetic radiation into an enclosed cavity to heat up a food load. The controller is configured to: (a) cause the generation of RF excitations at a specified frequency and phase shifts from each of the plurality of RF feeds for a predetermined time period; (b) during the predetermined time period: measure and analyze the backward power at the plurality of RF feeds to calculate efficiency, determine a coefficient of variation in the efficiency, and monitor the coefficient of variation to identify possible changes in a characteristic of the food load; and (c) repeatedly perform steps (a) and (b) until such time that a possible change is identified in a characteristic of the food load based on changes in the coefficient of variation. The characteristic may be the volume of the food load.

System and method for detecting changes in food load characteristics using coefficient of variation of efficiency

An electromagnetic cooking device and method of controlling the same is provided herein. The cooking device has a cavity in which a liquid is placed and a plurality of RF feeds configured to introduce electromagnetic radiation into the cavity for heating the liquid. A controller is provided and is configured to: analyze forward and backward power at the plurality of RF feeds to calculate efficiency; determine and monitor a coefficient of variation of the efficiency; detect a specified temperature of the liquid based on changes in the coefficient of variation; and adjust a power level of the electromagnetic radiation in response to detection of the specified temperature.

Electromagnetic cooking device with automatic liquid heating and method of controlling cooking in the electromagnetic cooking device

An electromagnetic cooking device and method of controlling the same is provided herein. The cooking device has a cavity in which a liquid is placed and a plurality of RF feeds configured to introduce electromagnetic radiation into the cavity for heating the liquid. A controller is provided and is configured to: analyze forward and backward power at the plurality of RF feeds to calculate efficiency; determine and monitor a coefficient of variation of the efficiency; detect a boiling state in the liquid based on changes in the coefficient of variation; and adjust a power level of the electromagnetic radiation in response to detection of the boiling state to prevent the liquid from splattering.

Electromagnetic cooking device with automatic anti-splatter operation

An electromagnetic cooking device is provided having a controller and a plurality of RF feeds configured to introduce electromagnetic radiation into an enclosed cavity to heat up a food load. The controller is configured to: select a heating target; generate a heating strategy to determine a sequence of desired heating patterns; cause the RF feeds to output an RF signal to thereby excite the enclosed cavity; monitor the created heating patterns to measure resonances in the enclosed cavity and store a map of efficiency in frequency and phase domains from which the controller identifies resonant modes and Q-factors associated therewith; continue to monitor the created heating patterns and store maps of efficiency in the frequency and phase domains until a specified change is detected in at least one Q-factor; and when the specified change in the at least one Q-factor is identified, stop cooking the food load.

Detecting changes in food load characteristics using Q-factor

An electromagnetic cooking device includes a cavity in which a food load is placed, a plurality of RF feeds for introducing electromagnetic radiation into the enclosed cavity, and a controller configured to detect asymmetries and select rotations that compensate for the asymmetries; select a heating target including a plurality of resonant modes that are rotated using the selected rotations in the preceding step; generate a heating strategy based on the heating target to determine a sequence of desired heating patterns; cause the RF feeds to output a radio frequency signal to thereby excite the enclosed cavity with a selected set of phasors for a set of frequencies; and monitor the created heating patterns based on the forward and backward power measurements at the RF feeds to use closed-loop regulation to selectively modify the sequence of resonant modes into the enclosed cavity based on the desired heating patterns as monitored.

Method and device for electromagnetic cooking using non-centered loads management through spectromodal axis rotation

An electromagnetic cooking device includes a cavity in which a food load is placed, a plurality of RF feeds for introducing electromagnetic radiation into the enclosed cavity, and a controller configured to select a heating target including a plurality of unrotated resonant modes; detect asymmetries of the food load relative to a center of the enclosed cavity and select rotations for the plurality of unrotated resonant modes that compensate for the detected asymmetries of the food load to generate a plurality of optimized resonant modes; generate a heating strategy having a selected sequence of the optimized resonant modes; cause the RF feeds to excite the enclosed cavity with a selected set of phasors for a set of frequencies corresponding to each resonant mode of the selected sequence of optimized resonant modes; and monitor the created heating patterns using closed-loop regulation to selectively modify the sequence of optimized resonant modes.

Method and device for electromagnetic cooking using non-centered loads

A method for controlling a power of an electromagnetic cooking device is shown. The method includes controlling a power supply to deliver a power level to the amplifier and monitoring at least one RF feed delivered to an enclosed cavity. The method further includes identifying an output power based on the RF feed and comparing the output power to a maximum power. A power difference of the output power compared to a target power is determined, and the power difference is compared to a plurality of difference thresholds. Based on the comparison, the power level is adjusted by a plurality of power adjustment magnitudes.

System and method for controlling power for a cooking device

An electromagnetic cooking device is disclosed. The device comprises an enclosed cavity configured to receive a food load and a plurality of amplifiers configured to amplify a first RF signal and a second RF signal thereby supplying the RF signals to the enclosed cavity. A controller is in communication with the plurality of amplifiers. The controller is configured to control the first RF signal and the second RF signal along a stirring path between a first approximate resonant mode and a second approximate resonant mode of the enclosed cavity. Each of the resonance modes comprises a frequency and phase shift between the first RF signal and the second RF signal.

Growing community of inventors

Brescia, Italy

Davide Guatta