KR100214614B1 - Magnetic and nonmagnetic combined heating induction cooker - Google Patents

Abstract

The present invention relates to a magnetic and nonmagnetic combined heating electromagnetic induction cooker, conventionally has a disadvantage that only a portion of the container is heated using only a portion of the working coil. Therefore, the present invention is to use all of the portion of the working coil that is not used in the prior art to increase the usability of the working coil and to eliminate the phenomenon of local heating.

Description

Magnetic and nonmagnetic combined heating induction cooker

1 is a circuit diagram of a conventional magnetic and nonmagnetic combined heating induction heating cooker.

2 is a circuit diagram of the magnetic and nonmagnetic combined heating electromagnetic induction cooker of the present invention.

3 is a first embodiment of the present invention magnetic and nonmagnetic combined heating electromagnetic induction cooker.

Figure 4 is a second embodiment of the present invention magnetic and nonmagnetic combined heating electronic induction cooker.

5 is a third embodiment of the present invention magnetic and nonmagnetic combined heating electronic induction cooker.

* Explanation of symbols for main parts of the drawings

100: half bridge inverter 200: series resonance unit

C _a1, C _a2 : auxiliary capacitor C _r1, C _r2: resonant capacitor

D _a1, D _a2 : auxiliary diode L _r1, L _r2 : working coil

Ry: relay S1, S2: first and second switch

The present invention relates to a half-bridge induction heating cooker capable of heating both magnetic and nonmagnetic, and in particular, to prevent the local heating phenomenon by using all of the working coils that previously used only a part of the working coils when heating the magnetic container, Magnetic and nonmagnetic combined heating electromagnetic induction heating cooker to increase the usability of the coil.

The circuit configuration of the conventional magnetic and nonmagnetic combined heating and cooking oil cooking apparatus, as shown in Figure 1, the rectifier 10 for rectifying the input commercial power (AC) to a DC voltage using a bridge diode; An LC filter (L _f and C _f ) for receiving the DC voltage rectified through the rectifying unit 10 and filtering and smoothing the power factor to improve the power factor; First and second switches S1 and S2 connected in series between an electrostatic terminal and a sub-power terminal for switching in response to a control signal and providing a resonance voltage; It is divided into two and connected to a common connection point of the first and second switches S1 and S2 to induce eddy currents in the cooking vessel by the resonance voltage supplied from the rectifying view 10 to heat food in the cooking vessel. A working coil (L _r1 ) (L _r2 ); A resonant capacitor C _r1 connected to the working coil L _r2 to change a frequency according to a container; A resonant capacitor (C _r21 ) (C _r22 ) which is continuously resonated with the working coil (L _r1 ) (L _r2 ) by a DC voltage connected in series between the electrostatic source terminal and the sub power supply terminal; It is connected between the connection point of the working coil (L _r1 ) (L _r2 ) and the connection point of the resonant capacitor (C _r21 ) (C _r22 ) is selected to operate only one working coil or to operate both working coils It consists of a relay switch Ry for controlling.

Looking at the prior art configured as described above in detail.

Conventionally, only ferromagnetic iron containers have been heated, but recently, research on induction heating cookers capable of heating non-magnetic aluminum containers has been actively conducted.

In general, it is well known to increase the number of turns of the working coil and increase the operating frequency compared to the iron-based container to heat the nonmagnetic container. Therefore, to heat both magnetic and nonmagnetic containers, the circuit constants must be changed for each container.

Therefore, when the magnetic load relay Ry is turned on _, L _r1, C _r21, C _r22 forms a resonant tank to operate as a half bridge, and when the non-magnetic load relay Ry is turned off, L _r , C _r1 , C _r21 and C _r22 form a resonant tank to operate another half bridge.

First, the nonmagnetic on-load operation is as follows.

When the nonmagnetic load is to be heated, first, the relay Ry is turned off, and the second switch S2 is turned off and the first switch S1 is turned on.

Then, in the resonant tanks L _r and C _r1, C _{r21 and} C _r22 , the DC voltage rectified and filtered through the rectifier 10 and the LC filters L _f and C _f (V _d ) is provided in the first switch S1. Is applied through, and thus the resonance starts to increase the current in the working coil L _r .

If the first switch S1 is turned off before the resonant half cycle passes, the auxiliary capacitors C _{a1 and} C _a2 resonate with the resonant tank so that the voltage of the auxiliary capacitor C _a2 drops from the V _d voltage to zero and the auxiliary voltage therebetween. The voltage on capacitor _Ca rises from zero to V _d .

Thereafter, the antiparallel diode D _a2 of the second switch S2 is turned on _, and zero voltage is applied to the resonant tanks L _{r , Cr r1, Cr r21, and Cr r22} .

Then, resonance occurs continuously by the voltage charged in the resonance capacitor, and at this time, the second switch S2 is turned on under the condition of zero voltage.

The resonance current drops to zero by the continuous resonance, and this time the resonance current increases by resonance in the opposite direction.

If the second switch S2 is turned off before the resonant half-cycle passes, the auxiliary capacitors C _{a1 and} C _{a2 perform} auxiliary resonance with the resonant tanks L _r and C _r1, C _{r21 and} C _r22 , thereby causing the auxiliary capacitor C _{a1 to be turned off} . the voltage will drop to zero in the voltage V _d of the voltage between the auxiliary capacitor (C _a2) is rising from zero to V _d.

Thereafter, the antiparallel diode D _a1 of the first switch S1 is turned on so that the voltage V _d is applied to the resonant tanks L _r and C _r1, C _{r21, and} C _r22 .

Then, resonance continues and at this time, the first switch S1 is turned on under the condition of zero voltage.

When the resonance current drops to zero due to the continuous resonance, one cycle of operation ends and the same operation is repeated.

The load is heated by the eddy current generated in the load by the induced current.

In the case of the magnetic load, the relay Ry is turned on and the operation is the same as the above operation. The only difference is that the resonant tank is composed of L _r1, C _{r21, and} C _r22 .

As described above, the relay Ry is turned on or off to change the number of turns of the working coil so that both the magnetic and nonmagnetic containers can be heated.

However, in the prior art as described above, when the magnetic container is heated, only a part of the container is heated because the working coil (L _r2 is not used at all and only a part of the working coil is used).

Accordingly, an object of the present invention for solving the above disadvantages is to use all of the working coil to use only a portion of the working coil when heating the magnetic container to increase the use of the working coil and to prevent the magnetic container is heated locally It is to provide an electric induction heating cooker.

Magnetic and nonmagnetic combined heating electromagnetic induction cooking circuit of the present invention for achieving the above object, as shown in Figure 2, a plurality of heating coils (L _r1, L _r2 ) and the resonance capacitor (C _{r1) ,} C _r2 ) and the series resonator 200; A half bridge inverter (100) comprising a first switch (S1) and a second switch (S2) capable of zero voltage switching capable of generating a high frequency current in the series resonator unit according to a control signal; The relay Ry is configured to switch the connection of the heating coil of the series resonator 200 and the resonance capacitor so that the resonance frequency can be changed.

Referring to the features and effects of the present invention configured as described above in detail.

In case of non-magnetic load, the relay Ry is turned off, and the working coil L _r and the resonant capacitor C _r2 form a resonant tank to form a high resonance frequency. In the case of magnetic load, the relay Ry is turned on in series. C _r1 is connected in parallel to L _r2 and C _r2 , and L _r1 is connected in series.

To do this, because the series L _r2 and C _r2 connected to the C _r1 connected in parallel and when excited L _r1 is coupled in series relative to C _r2 C _r1 has a very large capacity of the resonance frequency is mainly the L _r1 and C _r1 Is determined by.

In addition, the voltage of the C _r2 will follow the voltage of C _r1 because it takes a small voltage, L _r2 thus current flows in the L _r2, only a small current compared with the current of the L _r1.

This value is set according to the values of each resonant element, which is about 10-20%. Thus, the whole working coil is used even when the magnetic container is heated to eliminate the local heating phenomenon.

The operation when the heating vessel is a nonmagnetic load is as follows.

First, when the second switch S2 is turned off and the first switch S1 is turned on, the resonant tanks L _r and C _r2 are applied while the input voltage V _d is applied, and the resonance starts and the current starts to flow in L _r . do.

If the first switch S1 is turned off before the resonant half cycle passes, the auxiliary capacitors C _{a1 and} C _a2 resonate with the resonant tanks L _r and C _r2 so that the voltage of the auxiliary capacitor C _a2 is set at V _d . The voltage falls to zero, and the voltage of the auxiliary capacitor _{Ca 1} rises from zero to V _d .

Since the second switch (S2) the antiparallel diode (D _a2) of the resonant tank is conductive (L _r and C _r2), the applied voltage is zero.

Then, resonance is continuously generated in the resonant capacitor by the charged voltage. At this time, the second switch S2 is turned on under the condition of zero voltage.

The resonance current drops to zero by the continuous resonance, and this time the resonance current increases by resonance in the opposite direction.

If the second switch S2 is turned off before the resonant half cycle passes, the capacitors C _{a1 and} C _a2 resonate with the resonant tanks L _r and C _r2 so that the voltage of the auxiliary capacitor C _a1 can be _changed from V _d to zero. In the meantime, the voltage of the auxiliary capacitor _{Ca a2} rises from zero to V _d .

Thereafter, the antiparallel diode D _a1 of the first switch S1 is turned on so that the voltage V _d is applied to the resonant tanks L _r and C _r2 .

Then, resonance continues and at this time, the first switch is turned on under the condition of zero voltage.

When the resonance current drops to zero due to the continuous resonance, one cycle of operation ends and the same operation is repeated.

The load is heated by the eddy current generated in the load by the induced current.

In magnetic load, the same operation as in non-magnetic load, but the difference is that as mentioned earlier, C _r1 is connected in parallel to L _r2 and C _r2 connected in series by turning on the relay (Ry), and L _r1 is in series. It works by using a resonant tank connected with

As described above, the relay Ry is turned on or off under magnetic and nonmagnetic load so as to operate the resonant tanks differently so that all the containers can be heated.

In another embodiment, the resonant tank is connected to the first switch as shown in FIG. 3, and in this case, the roles of the two switches are reversed.

4 is divided into two resonant capacitors (C _r1 ) used to heat the magnetic container, one connected to the collector terminal of the first switch (S1) and the other to the emitter terminal of the second switch (S2). The operation is the same.

Finally, FIG. 5 divides the resonant capacitor C _r2 , which is used to heat the nonmagnetic container, into two, one of which is connected to the collector terminal of the first switch S1 and the other to the emitter terminal of the second switch S2. The operation is the same.

As described in detail above, the present invention has an effect of increasing the usability of the working coil and eliminating local heating by using a part of the working coil that is not used in the related art.

Claims (2)

A series resonator 100 comprising a plurality of heating coils L _{r1 and} L _r2 and resonant capacitors C _{r1 and} C _r2 ; According to a control signal, zero voltage switching capable of generating a high frequency current in the series resonance unit 100 is possible, and the first switch S1 and the second switch S2 connected in series between the electrostatic source terminal and the sub-power terminal. In the electromagnetic induction heating vessel consisting of a half bridge inverter 100 made of a), the series resonator 100 is a heating coil separated at a common connection point of the first switch (S1) and the second switch (S2) to connect the (L _r1, L _r2), and the heating coil of the relay (Ry) and the resonance and the second switch (S2) to the capacitor (C _r2) for the switching means is connected to the common connection point of the (L _r1, L _r2) Magnetic and characterized in that it is configured in parallel, and configured to connect another resonance capacitor (C _r2 ) connected to the heating coil (L _r2 ) in parallel with the relay (Ry) and the resonance capacitor (C _r2 ). Non-magnetic combined heating induction cooker. The magnetic induction and nonmagnetic heating electromagnetic induction heating cooker according to claim 1, wherein the series resonator unit 100 is connected to the first switch S1 in parallel.