Dual coil induction heating system
View Patent ↗A dual coil induction cooking system and method for heating ferrous and non-ferrous cooking vessels. The system includes a first resonant circuit for inducing a current in a ferrous metal cooking vessel at a first frequency and a second resonant circuit, wired in a parallel combination with the first resonant circuit, for inducing a current in a non-ferrous metal cooking vessel at a second frequency. The system also includes a power source for powering the parallel combination, so that one of the first and the second resonant circuits is coupled to supply power through the parallel combination to a respective one of the cooking vessels. A method for coupling power to a load includes sweeping a parallel combination of resonant circuits with a variable frequency power, detecting a resonant frequency response corresponding to a metallic composition of the load, and simultaneously powering the parallel combination of resonant circuits at a frequency corresponding to the detected resonant frequency.
1. A dual coil induction cooking system comprising:
a first resonant circuit for inducing a current in a ferrous metal cooking vessel at a first frequency;
a second resonant circuit, wired in a parallel combination with the first resonant circuit, for inducing a current in a non-ferrous metal cooking vessel at a second frequency; and
a power source for powering the parallel combination, without changing a wiring arrangement to the parallel combination, so that one of the first and the second resonant circuits is coupled to supply power through the parallel combination to a respective one of the cooking vessels.
2. The system of claim 1 , wherein the first resonant circuit further comprises a first capacitor and a first coil wired in series.
3. The system of claim 2 , wherein the first resonant circuit further comprises an inductor wired in series with the first capacitor and the first coil.
4. The system of claim 1 , wherein the second resonant circuit comprises a second capacitor and a second coil wired in series.
5. The system of claim 4 , wherein the second resonant circuit further comprises an inductor wired in series with the second capacitor and the second coil.
6. The system of claim 1 , wherein the power source is configured to operate at the first frequency and the second frequency.
7. The system of claim 1 , wherein the power source is configured to operate at an intermediate frequency between the first frequency and the second frequency.
8. The system of claim 1 , wherein the power source further comprises a frequency varying circuit for sequentially varying a frequency of power provided to the parallel combination.
9. The system of claim 8 , wherein the frequency varying circuit is configured to vary the frequency of power provided to the parallel combination from a comparatively higher frequency to a comparatively lower frequency.
10. The system of claim 8 , wherein the frequency varying circuit is configured to vary the frequency of power provided to the parallel combination from a comparatively lower frequency to a comparatively higher frequency.
11. The system of claim 1 , wherein the power source further comprises a detector for identifying at least one resonant frequency of the parallel combination.
12. A dual coil induction cooking system comprising:
a first series resonant circuit comprising a first cooking coil, the first series resonant circuit tuned to resonate at a first frequency with a first load;
a second series resonant circuit comprising a second cooking coil, the second series resonant circuit wired in a parallel circuit with the first series resonant circuit and tuned to resonate at a second frequency with a second load; and
a frequency source for driving the parallel circuit.