Multi-coil induction hob and method
AssigneeTrustees of Dartmouth College
InventorsFridon Shubitidze, Robert Vincent Stigliano
Life of this patent
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Abstract
An induction hob uses induction heating to provide safe, energy efficient and flexible heating of vessels by using multiple coils and a controllable magnetic fluid. In addition, the hob provides increased control over electromagnetic (EM) field spatial distribution in the vicinity of the hob by guiding the EM field through the controllable magnetic fluid, and allows for more precise tuning of each load (which varies with vessel geometry, material properties, and placement) by controlling the volume and spatial distribution of magnetic fluid at each load coil, effectively acting as a tunable inductance in each load.
Claims21
A multi-coil induction hob, comprising:
- a plurality of coils;
- magnetic fluid;
- and
- control circuitry for detecting one or more active coils of the plurality of coils and for causing the magnetic fluid to aggregate near the one or more active coils.
A multi-coil induction hob, comprising:
- a plurality of work coils arranged in an array forming a plane;
- a plurality of holding coils, each holding coil associated with a work coil and rotated out of the plane formed by the array of work coils;
- magnetic fluid;
- control circuitry for detecting a presence of a vessel above one or more active coils of the plurality of work coils;
- a DC (direct current) source operatively coupled to the plurality of holding coils, said DC source causing the magnetic fluid to aggregate near the one or more active coils by supplying current to one or more holding coils associated with the one or more active coils;
- and
- an AC (alternating current) source operatively coupled to the plurality of work coils for transmitting AC to the plurality of work coils.
A method of operating a multi-coil induction hob comprising a plurality of work coils, a plurality of holding coils and magnetic fluid, the method comprising:
- determining active work coils by testing for each of the plurality of work coils an impedance indicating a presence of cookware above the work coil and a magnitude of alternating current (AC) needed for heating the work coil to a temperature input by a user;
- connecting a direct current (DC) source to one or more holding coils, each associated with an active work coil, for drawing magnetic fluid to the one or more holding coils;
- continuing to test the impedance of the active coils while increasing the direct current until a desired load impedance is achieved;
- and
- connecting an AC source to the plurality of work coils.
Dependencies are inferred from the claim text.