Temperature self-regulating food delivery system
DCFirst Claim
1. In a method of heating a ferromagnetic heating element including the steps of magnetically coupling the element with the magnetic field of a magnetic field generator in order to heat said element, said magnetic field produced by an induction coil, said induction coil forming a part of a resonant circuit, the improvement which comprises the steps of controlling the temperature of said element about a regulation temperature of the element by detecting an induction heater circuit parameter related to the amplitude of the resonant current passing through the resonant circuit, and altering the field strength of said magnetic field in response to the magnitude, or rate of change of said magnitude, of said detected parameter, said controlling and altering steps occurring during the course of heating of said element.
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Accused Products
Abstract
Temperature self-regulating food delivery systems are provided having a magnetic induction heater (32, 126) and an associated food container (76, 124) equipped with an essentially permanent ferromagnetic heating element (82, 100, 128). The heater (32, 126) and heating elements (82,100, 128) are designed so as to heat the element (82, 100, 128) to a user-selected regulation temperature when the elements (82, 100, 128) are coupled with the heater'"'"'s magnetic field, and to maintain the temperature in the vicinity of the regulation temperature indefinitely temperature regulation is a heating achieved by periodically determining at least two parameters of the heaters resonant circuits related to the amplitude of the resonant current passing therethrough during heating and responsively altering the field strength of the magnetic field. Preferably, the value of the resonant circuit amplitude and the rate of change of the amplitude are determine.
104 Citations
21 Claims
- 1. In a method of heating a ferromagnetic heating element including the steps of magnetically coupling the element with the magnetic field of a magnetic field generator in order to heat said element, said magnetic field produced by an induction coil, said induction coil forming a part of a resonant circuit, the improvement which comprises the steps of controlling the temperature of said element about a regulation temperature of the element by detecting an induction heater circuit parameter related to the amplitude of the resonant current passing through the resonant circuit, and altering the field strength of said magnetic field in response to the magnitude, or rate of change of said magnitude, of said detected parameter, said controlling and altering steps occurring during the course of heating of said element.
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6. Food temperature control apparatus comprising:
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a container including a ferromagnetic induction heating element;
a magnetic induction heater including a magnetic field generator for generating a magnetic field, said heater including a resonant circuit having an induction coil;
said heater operable to heat said element when the element is magnetically coupled with said magnetic field; and
a temperature controller for controlling the temperature of said element during the course of heating of the element including a detector operable to detect an induction heater circuit parameter related to the amplitude of the resonant current passing through the resonant circuit, and control circuitry operable to alter the magnetic field strength of said magnetic field in response to the magnitude, or rate of change of said magnitude, of said detected parameter. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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- 17. In a method of heating a ferromagnetic heating element including the steps of magnetically coupling the element with the magnetic field of a magnetic field generator in order to heat said element, said magnetic field produced by an induction coil, said induction coil forming a part of a resonant circuit, the improvement which comprises the steps of controlling the temperature of said element between predetermined limits by detecting an induction heater circuit parameter related to the amplitude of the resonant current passing through the resonant circuit, and altering the field strength of said magnetic field in response to the magnitude, or rate of change of said magnitude, of said detected parameter, said controlling and altering steps occurring during the course of heating of said element.
Specification