US Patent 9282593 Device and system for induction heating

An induction heating system comprises inductive rings, which in one example are concentrically wound about a center axis to form a coil array. The inductive rings are situated in the coil array to permit activation of the inductive rings independent of the other inductive rings in the coil array. In one embodiment, the induction heating system includes a control structure with a power supply and switches coupled to each of the inductive rings, wherein activation of the switches permits current from the power supply to flow to the corresponding inductive ring. The induction heating system is amenable to appliances such as ovens and ranges, as well as to cooktops such as free-standing cooktops for countertops.