Electronic cooking appliance

Claim 1

IN A COOKING APPLIANCE, METAL WALL STRUCTURE DEFINING A SUBSTANTIALLY CLOSED COOKING CAVITY, A PAIR OF SPACEDAPART ELECTRODES MOUNTED IN SAID COOKING CAVITY AND CONSTITUTING A CAPACITOR AND ADAPTED TO RECEIVE THEREBETWEEN THE FOOD TO BE COOKED BY ELECTROSTATIC HEATING THEREOF, WHEREBY THE CAPACITANCE OF SAID CAPACITOR IS DEPENDENT UPON THE CHARACTERISTIC LOAD IMPEDANCE OF THE FOOD BEING COOKED, AN INDUCTOR, MEANS CONNECTING TOGETHER SAID CAPACITOR AND SAID INDUCTOR TO DEFINE A TANK CIRCUIT, APPARATUS OPERATIVELY ASSOCIATED WITH SAID INDUCTOR AND SELECTIVELY OPERATIVE TO ADJUST THE INDUCTANCE THEREOF, AN AMPLIFYING DEVICE HAVING FIRST AND SECOND POWER TERMINALS AND A CONTROL TERMINAL, A SOURCE OF OPERATING POTENTIAL FOR SAID AMPLIFYING DEVICE, MEANS CONNECTING THE TERMINALS OF SAID AMPLIFYING DEVICE AND SAID TANK CIRCUIT AND SAID SOURCE OF POTENTIAL TO DEFINE AN OSCILLATOR HAVING A RESONANCE FREQUENCY IN THE HIGH FREQUENCY BAND THAT IS DEPENDENT UPON THE CAPACITANCE OF SAID CAPACITOR AND UPON THE INDUCTANCE OF SAID INDUCTOR AND THAT IS CHARACTERIZED BY A MINIMUM CURRENT THROUGH SAID AMPLIFYING DEVICE WHEN SAID OSCILLATOR IS OPERATING AT THE RESONANCE FREQUENCY THEREOF AND BY AN INCREASE IN THE CURRENT THROUGH SAID AMPLIFYING DEVICE WHEN SAID OSCILLATOR IS OPERATING AT A FREQUENCY IN THE HIGH FREQUENCY BAND OTHER THAN AT THE RESONANCE FREQUENCY THEREOF, WHEREBY A CHANGE IN THE CHARACTERISTIC LOAD IMPEDANCE OF THE FOOD BEING COOKED IS OPERATIVE TO CHANGE THE CAPACITANCE OF SAID CAPACITOR AND CONSEQUENTLY THE OPERATING FREQUENCY OF SAID OSCILLATOR TO INCREASE THE CURRENT THROUGH SAID AMPLIFYING DEVICE, AND MEANS RESPONSIVE TO AN INCREASE IN THE CURRENT THROUGH SAID AMPLIFYING DEVICE FOR OPERATING SAID APPARATUS TO ADJUST THE INDUCTANCE OF SAID INDUCTOR TO A VALUE SO AS TO EFFECT OPERATION OF SAID OSCILLATOR SUBSTANTIALLY AT THE RESONANCE FREQUENCY THEREOF, THEREBY TO COMPENSATE FOR DIFFERENT CHARACTERISTIC LOAD IMPEDANCES OF THE FOOD BEING COOKED.