Patent ID: 8754351

Claim:
An induction cooking system comprising: (a) an induction cooking appliance comprising: (i) a cooktop having an upper and lower surface; (ii) power electronics located below the lower surface of the cooktop; (iii) an electrical coil positioned immediately below and spaced from the lower surface of the cooktop, wherein the electrical coil is operatively connected to the power electronics and configured to produce an electromagnetic field when the coil is energized by the power electronics; and (iv) one or more cooktop cooling fans that cause air to flow over at least the lower surface of the cooktop: (b) custom cookware configured to be placed on the cooktop above the electrical coil, the custom cookware comprising: (i) an inner wall that forms a cavity to hold a substance, and that heats the substance; (ii) an outer wall made at least in part of electrically non-conductive material, where the outer wall has a lower wall portion that is spaced from the inner wall and that is configured to rest on the upper surface of the cooktop above the electrical coil during cooking; (iii) a seal between the inner and outer walls; (iv) a target layer located at least in part in the space between the inner wall and the lower portion of the outer wall and formed of an electrically conductive material, wherein an electrical current is induced in the target layer by the electromagnetic field generated by the coil, where the target layer is thermally coupled to the inner wall such that it heats the inner wall when current is induced in the target layer; (v) a first layer of thermal insulation material that is spaced from the target layer such that there is a gap between the thermal insulation and the target layer; (vi) a gas or vacuum in the space between the inner and outer walls, and wherein the thermal resistance of the space between the inner and outer walls and the first layer of thermal insulation material in combination is at least 10 degrees C. per watt; (vii) a temperature sensor located within the cookware and that senses a temperature of the cookware; (viii) a transmitter operatively coupled to the temperature sensor, the transmitter wirelessly transmitting a signal related to the temperature sensed by the temperature sensor; and (ix) a power coil tuned to couple to an electromagnetic field produced by the electrical coil to generate electrical power that is provided to the transmitter so as to operate the transmitter; wherein the induction cooking appliance further comprises a controller that receives the signal from the transmitter and in response controls the cooling fans.