Patent US3786219A successfully refreshed from Google Patents.
US3786219A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid state induction cooking systems for ranges and surface cooking units
Assignee: General Electric Co
•
Filing: 1971-12-27
•
Granted: 1974-01-15
•
Expires: 1991-12-27
Abstract
Abstract Solid state induction surface cooking units for domestic electric ranges and other cooking appliances are defined with respect to the operating parameters and functional components of complete induction heating systems suited for this use. The surface cooking units are designed for reliable, convenient, and safe operation, and for circuit packaging using hybrid and monolithic integrated circuits. Wide range power control of the inverter power circuits is needed for general cooking but is obtained within a limited ultrasonic operating range of the power semiconductors. The inter-dependent electrical and magnetic characteristics utilized in solid state induction cooking are related to the achievement of such desirable user features as the cool cooking surface, fast utensil warm-up, responsive heating, and unrestrained utensil mobility. In addition to cooking by changing the relative heating level, cooking is performed by setting the desired utensil temperature and by setting the desired utensil power level.
Inventors
- 👤 W Kornrumpf
- 👤 J Harnden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:24
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/06; H05B6/062; G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; H02; H02M; H02M5/00; H02M5/02; H02M5/04; H02M5/22; H02M5/25; H02M5/27; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/523; H02M7/525; H02M7/53; H02M7/537; H02M7/5387; H02M7/53871; H02M1/00; H02M1/0083; H02M1/0085
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
114 words
A domestic induction surface cooking unit comprising a nominally flat induction heating coil mounted adjacent a substantially unbroken non-metallic utensil support to thereby provide a relatively cool cooking surface, a solid state power conversion circuit for converting a supply voltage to ultrasonic output power that drives said induction heating coil and generates an alternating magnetic field for coupling the power to a cooking utensil, wherein the ultrasonic output power is between 50 and 2,500 watts and has a frequency between 18 and 40 kilohertz, and the solid state power conversion circuit produces wide range ultrasonic output power for general cooking purposes with a ratio of maximum to minimum output power of 10:1 to 50:1.
Claim 2
Dependent Claim
114 words
A domestic induction surface cooking unit comprising a nominally flat induction heating coil mounted adjacent a substantially unbroken non-metallic utensil support to thereby provide a relatively cool cooking surface, a solid state power conversion circuit for converting a supply voltage to ultrasonic output power that drives said induction heating coil and generates an alternating magnetic field for coupling the power to a cooking utensil, wherein the ultrasonic output power is between 50 and 2,500 watts and has a frequency between 18 and 40 kilohertz, and the solid state power conversion circuit produces wide range ultrasonic output power for general cooking purposes with a ratio of maximum to minimum output power of 10:1 to 50:1.
Claim 3
Dependent Claim
26 words
A cooking unit according to claim 1 in which the maximum output power is about 1,500 watts and the minimum output power is about 50 watts.
Claim 4
Dependent Claim
53 words
A cooking unit according to claim 1 in which said solid state power conversion circuit includes a full bridge inverter constructed with power semiconductors that produce rectangular voltage pulses, and means for controlling said power semiconductors to pulse width modulate said rectangular voltage pulses to adjust the power coupled to the cooking utensil.
Claim 5
Dependent Claim
26 words
A cooking unit according to claim 3 in which said bridge inverter is additionally operated at a variable ultrasonic frequency to achieve wide range power control.
Claim 6
Dependent Claim
138 words
A domestic induction surface cooking unit comprising a nominally flat induction heating coil mounted adjacent a substantially unbroken non-metallic utensil support to thereby provide a relatively cool cooking surface, a solid state power conversion circuit for converting a supply voltage to ultrasonic output power that drives said induction heating coil and generates an alternating magnetic field for coupling the power to a cooking utensil, wherein the output power is between 50 and 2,500 watts and has a frequency between 18 and 40 kilohertz, and said solid state power conversion circuit produces a unidirectional voltage and includes filter means for filtering the unidirectional voltage, and further includes an inverter energized by the filtered unidirectional voltage that produces wide range ultrasonic output power for general cooking purposes with a ratio of maximum to minimum output power of 10:1 to 50:
Claim 7
Dependent Claim
138 words
A domestic induction surface cooking unit comprising a nominally flat induction heating coil mounted adjacent a substantially unbroken non-metallic utensil support to thereby provide a relatively cool cooking surface, a solid state power conversion circuit for converting a supply voltage to ultrasonic output power that drives said induction heating coil and generates an alternating magnetic field for coupling the power to a cooking utensil, wherein the output power is between 50 and 2,500 watts and has a frequency between 18 and 40 kilohertz, and said solid state power conversion circuit produces a unidirectional voltage and includes filter means for filtering the unidirectional voltage, and further includes an inverter energized by the filtered unidirectional voltage that produces wide range ultrasonic output power for general cooking purposes with a ratio of maximum to minimum output power of 10:1 to 50:
Claim 8
Dependent Claim
26 words
A cooking unit according to claim 5 in which the maximum output power is about 1,500 watts and the minimum output power is about 50 watts.
Claim 9
Dependent Claim
45 words
A cooking unit according to claim 5 in which said solid state power conversion circuit includes a time ratio control circuit coupled between said filter means and inverter for changing the magnitude of the filtered uni-directional voltage energizing the inverter for wide range power control.
Claim 10
Dependent Claim
194 words
A domestic induction surface cooking unit comprising a nominally flat induction heating coil mounted adjacent a substantially unbroken non-metallic utensil support plate to thereby provide a relatively cool cooking surface, a static power conversion circuit including filter means and an inverter controlled by solid state power device means for converting a filtered unidirectional voltage to an ultrasonic frequency wave that drives said induction heating coil for coupling output power to a cooking utensil, a gating circuit for selecting the intervals of conduction of said power device means, an inhibit circuit coupled to said gating circuit for selectively inhibiting operation of said inverter, start-up and shut-down circuit means coupled to said inhibit circuit and gating circuit for controlling starting and stopping transients and the application to and removal of voltage from said inverter, device protection means for protecting said power device means from undesired voltages and currents, output power adjustment means coupled to said gating circuit and inhibit circuit for varying the output power of said inverter and therefore the heating level of the utensil, and user control means for energizing and de-energizing said static power conversion circuit and setting a selected utensil heating level.
Claim 11
Dependent Claim
194 words
A domestic induction surface cooking unit comprising a nominally flat induction heating coil mounted adjacent a substantially unbroken non-metallic utensil support plate to thereby provide a relatively cool cooking surface, a static power conversion circuit including filter means and an inverter controlled by solid state power device means for converting a filtered unidirectional voltage to an ultrasonic frequency wave that drives said induction heating coil for coupling output power to a cooking utensil, a gating circuit for selecting the intervals of conduction of said power device means, an inhibit circuit coupled to said gating circuit for selectively inhibiting operation of said inverter, start-up and shut-down circuit means coupled to said inhibit circuit and gating circuit for controlling starting and stopping transients and the application to and removal of voltage from said inverter, device protection means for protecting said power device means from undesired voltages and currents, output power adjustment means coupled to said gating circuit and inhibit circuit for varying the output power of said inverter and therefore the heating level of the utensil, and user control means for energizing and de-energizing said static power conversion circuit and setting a selected utensil heating level.
Claim 12
Dependent Claim
29 words
A cooking unit according to claim 8 further including surge protection means and a radio frequency interference filter connected across the input terminals of said static power conversion circuit.
Claim 13
Dependent Claim
46 words
A cooking unit according to claim 8 wherein said static power conversion circuit further includes a full wave rectifier and means for controlling the magnitude oF the filtered unidirectional voltage to obtain wide range control of the output power and therefore of the utensil heating level.
Claim 14
Dependent Claim
21 words
A cooking unit according to claim 8 further including cooling means for said induction heating coil and static power conversion circuit.
Claim 15
Dependent Claim
29 words
A cooking unit according to claim 8 further including a current meter located between said filter means and inverter for displaying the state of the circuit to the user.
Claim 16
Dependent Claim
41 words
A cooking unit according to claim 8 further including utensil presence detection circuit means coupled to said gating circuit for sensing the absence of a cooking utensil coupled to said induction heating coil and modifying the operation of said gating circuit.
Claim 17
Dependent Claim
40 words
A cooking unit according to claim 8 wherein said device protection means comprises means for monitoring the filtered unidirectional voltage supplied to said inverter and actuating said inhibit circuit in response to the sensing of a predetermined low voltage level.
Claim 18
Dependent Claim
47 words
A cooking unit according to claim 8 wherein said device protection means comprises means for monitoring the voltage at a terminal of said solid state power device means and reducing the power output of said inverter in response to the sensing of a predetermined high voltage level.
Claim 19
Dependent Claim
156 words
A solid state induction surface cooking unit comprising an induction heating coil for inductively heating a cooking utensil, a solid state power conversion circuit for converting a unidirectional voltage to variable ultrasonic output power that is applied to said induction heating coil and produces a range of utensil heating levels, a gating circuit for controlling said solid state power conversion circuit to produce a heating level in dependence upon the algebraic sum of a plurality of input signals, a plurality of control logic circuits each generating one of said input signals and including start circuit means, stop circuit means, watts control means, user safety means, and circuit protection means, summing means for deriving the sum of the control logic circuit input signals and applying the sum to said gating circuit, and user control means for energizing and de-energizing said solid state power conversion circuit and setting said watts control means to obtain a selected heating level.
Claim 20
Dependent Claim
156 words
A solid state induction surface cooking unit comprising an induction heating coil for inductively heating a cooking utensil, a solid state power conversion circuit for converting a unidirectional voltage to variable ultrasonic output power that is applied to said induction heating coil and produces a range of utensil heating levels, a gating circuit for controlling said solid state power conversion circuit to produce a heating level in dependence upon the algebraic sum of a plurality of input signals, a plurality of control logic circuits each generating one of said input signals and including start circuit means, stop circuit means, watts control means, user safety means, and circuit protection means, summing means for deriving the sum of the control logic circuit input signals and applying the sum to said gating circuit, and user control means for energizing and de-energizing said solid state power conversion circuit and setting said watts control means to obtain a selected heating level.
Claim 21
Dependent Claim
45 words
A cooking unit according to claim 16 in which said solid state power conversion circuit includes input voltage control means for reducing the magnitude of said unidirectional voltage for wide range control of the ultrasonic output power and therefore the range of utensil heating levels.
Claim 22
Dependent Claim
49 words
A cooking unit according to claim 16 in which said user safety means comprises a utensil presence detection circuit that is operative when metallic objects significantly smaller than a cooking utensil are coupled with said induction heating coil as well as when a cooking utensil is not coupled therewith.
References Cited (Backward Citations)
US26974A
Cited
US2971754A
Cited
US3075136A
Cited
US3256417A
Cited
US3260916A
Cited
US3320512A
Cited
US3506907A
Cited
US3551632A
Cited
US3518527A
Cited
US3637970A
Cited
US3710062A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |