Induction heating circuit and winding method for heating coils
View Patent ↗A heating circuit for heating a conductive bowl includes a voltage source; a first heating coil provided between first and second nodes and being configured to heat the conductive bowl; a second heating coil provided between the second node and a third node and being configured to heat the conductive bowl; first capacitor and first switch provided in parallel between the first node and a fourth node; and second capacitor and second switch provided in parallel between the third node and the fourth node. The first and second heating coils define a circle-like shape having a center. The first and second heating coils are configured to be aligned to each other if one of the first and second heating coils is moved with respect to a line extending through the center of the circle-like shape.
1. A heating circuit for heating a conductive bowl, the circuit comprising:
a voltage source;
a first heating coil provided between first and second nodes and being configured to heat the conductive bowl;
a second heating coil provided between the second node and a third node and being configured to heat the conductive bowl;
first capacitor and first switch provided in parallel between the first node and a fourth node; and
second capacitor and second switch provided in parallel between the third node and the fourth node,
wherein the first and second heating coils define a circle-like shape having a center, and
wherein the first and second heating coils are overlapping each other at a plurality of points, the points defining a line extending through the center of the circle-like shape.
2. The heating circuit of claim 1 , wherein the first and second coils have substantially the same shape and size to provide substantially the same inductance.
3. The heating circuit of claim 1 , further comprising:
an inductor coupled to the second node and the voltage source;
a first diode provided anti-parallel to the first switch; and
a second diode provided anti-parallel to the second switch.
4. The heating circuit of claim 3 , wherein the first and second switches are IGBTs or BJTs.
5. The heating circuit of claim 1 , wherein the conductive bowl and the first and second heating coils define a transformer, wherein the first and second heating coils are configured to heat the conductive bowl, the conductive bowl having a single layer of metal, the heating circuit is a push-pull type heating circuit.
6. The heating circuit of claim 5 , wherein the single layer of metal is an aluminum layer.
7. A device for heating or cooking food, the device comprising:
a conductive bowl having a single layer of metal;
a voltage source;
a first heating coil provided between first and second nodes and being configured to heat the conductive bowl;
a second heating coil provided between the second node and a third node and being configured to heat the conductive bowl;
first capacitor and first switch provided in parallel between the first node and a fourth node; and
second capacitor and second switch provided in parallel between the third node and the fourth node,
wherein the first and second heating coils define a circle-like shape having a center, and
wherein the first and second heating coils are configured to overlap each other at a plurality of points, the points defining a line extending through the center of the circle-like shape.
8. The device of claim 7 , further comprising:
an inductor coupled to the second node and the voltage source;
a first diode provided anti-parallel to the first switch; and
a second diode provided anti-parallel to the second switch,
wherein the device uses a push-pull type heating circuit to heat the conductive bowl.
9. The device of claim 7 , wherein the conductive bowl and the first and second heating coils define a transformer, wherein the single layer of metal is an aluminum layer.
10. The heating circuit of claim 7 , wherein the first and second heating coils rotated about the line by 180 degrees from each other.