KR100253550B1 - Magnetic and nonmagnetic induction cookers - Google Patents

Abstract

PURPOSE: An induction heating cooking device with magnetism and non magnetism is provided to reduce a manufacturing cost by replacing a high voltage relay with a low voltage relay. CONSTITUTION: An induction heating cooking device with magnetism and non magnetism comprises a rectification portion(101), a voltage branch portion(102), a heating portion(103), a load selection switching portion(104), and a switching portion(105). The rectification portion(101) rectifies a direct voltage to an alternative voltage. The voltage branch portion(102) branches the direct voltage. The heating portion(103) heats a plurality of heating plates. The load selection switching portion(104) heats selectively the load of the heating portion(103). The switching portion(105) comprises the first and the second switching devices(S1,S2).

Description

Magnetic and nonmagnetic induction cookers

The present invention relates to a magnetic and nonmagnetic combined induction heating cooker, and in particular, by replacing the high-voltage relay for changing the resonant frequency according to the load with a low-pressure relay, and also by switching while removing the resonant capacitor when heating the magnetic container Magnetic and nonmagnetic combined induction heating cooker to minimize the cost and volume of the entire system.

As shown in FIG. 1, the magnetic and nonmagnetic electromagnetic induction heating cooker according to the prior art includes a rectifier circuit unit 1 for rectifying an input AC power source into a DC power source, and the rectifier circuit unit 1. LC smoothing circuit unit 2 for smoothly smoothing the DC power rectified through the filter inductor Lf and the filter capacitor Cf, and first and second walking to resonate the output voltage of the LC smoothing circuit unit 2. LC resonant circuit portion 3 comprising a working coil portion Lr consisting of coils Lr1 and Lr2, first to third resonant capacitors Cr1 to Cr3, and a resonant frequency selecting relay Ry for selecting a load; It is composed of a switching circuit section 4 consisting of first and second switches S1 and S2 which are selectively switched in accordance with a control signal input from the LC resonant circuit section 3 to supply power to the LC resonant circuit section 3 to perform a heating operation. .

In the drawings, reference numerals D1, D2, and Ca1, Ca2 are antiparallel diodes for improving bandwidth and phase characteristics of the LC resonant circuit unit 3 and auxiliary resonance capacitors for auxiliary resonance.

Referring to Figure 1 attached to the operation of the combined magnetic and nonmagnetic electromagnetic induction heating cooker according to the prior art configured as described above are as follows.

First, the resonant frequency selection relay Ry of the LC resonant circuit unit 3 under magnetic load is turned on so that the first working coil Lr1 and the second and third resonant capacitors Cr2 and Cr3 form a resonant circuit. In this case, the resonant frequency selection relay Ry is turned off when the non-magnetic load is applied, and the working coil part Lr and the first to third resonant capacitors Cr1 to Cr3 form a resonant circuit. To form another half bridge.

Here, the operation of the nonmagnetic load is as follows.

First, when the second switch S2 in the switching circuit section 4 is turned off and the first switch S1 is turned on in response to an external control signal, the working coil Lr and the first through the first to the first in the LC resonant circuit section 3 are turned on. The input voltage Vd is applied to the three resonant capacitors Cr1 to Cr3, and resonance starts to cause a current to rise in the working coil Lr.

At this time, if the first switch S1 in the switching circuit section 4 is turned off before the resonant half cycle passes, the first and second auxiliary resonance capacitors Ca1 and Ca2 perform auxiliary resonance with the LC resonance circuit section 3 to perform The voltage of the second auxiliary resonance capacitor Ca2 drops from the input voltage Vd to zero while the voltage of the first auxiliary resonance capacitor Ca1 rises from zero to the input voltage Vd.

Thereafter, the anti-parallel diode D2 of the second switch S2 in the switching circuit section 4 is turned on so that zero voltage is applied to the LC resonant circuit section 3.

Then, resonance continues by the voltage charged in the first to third resonant capacitors Cr1 to Cr3 in the LC resonant circuit part 3, and at this time, the second switch S2 in the switching circuit part 4 is set to zero voltage. Turn on under conditions.

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

When the second switch S2 in the LC resonant circuit part 3 is turned off before the resonant half cycle passes, the first and second auxiliary capacitors Ca1 and Ca2 resonate with the LC resonant circuit part 3 to perform the first auxiliary. The voltage of the capacitor Ca1 drops from the input voltage Vd to zero, while the voltage of the second auxiliary capacitor Ca2 rises from zero to the input voltage Vd.

Thereafter, the antiparallel diode D1 of the first switch S1 is turned on so that the input voltage Vd is applied to the LC resonant circuit portion 3.

Then, resonance continues and at this time, the first switch S1 of the switching circuit section 4 is turned on under the condition of zero voltage.

Thereafter, when the resonance current drops to zero by the continuous resonance, one cycle of operation is terminated and the same operation is repeated.

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

The magnetic load operation is the same, but the only difference is that the LC resonant circuit portion 3 is composed of the first working coil Lr1, the second and third resonant capacitors Cr2 and Cr3.

However, such a conventional magnetic and nonmagnetic electromagnetic induction heating cooker has a problem that it is difficult to manufacture the relay due to excessive voltage of several thousand volts (V) in the operation of the nonmagnetic load and the price is also increased, and also the resonant capacitor when the magnetic container is heated. Since two more should be attached, there was a problem in that the cost of the entire system and the volume became large.

Therefore, the present invention replaces the high voltage relay for changing the resonant frequency according to the load with the low voltage relay and removes the resonant capacitor when heating the magnetic container, thereby enabling switching to minimize the cost and volume of the entire system. The purpose is to provide a nonmagnetic combined induction heating cooker.

The technical means of the present invention for achieving this purpose, the voltage branching means for branching the input voltage and improve the power factor, and the resonant circuit generates heat in accordance with the input voltage branched by the voltage branching means to load (magnetic / Non-magnetic) and a heating means for selectively heating the plurality of heating plates, and a resonance circuit together with the resonance circuit, but are switched in accordance with an external control signal to time-sharing the load (magnetic / non-magnetic) of the heating means. Load selection switching means for selecting and heating, and switching means for switching power according to an external control signal to supply power to heat the heating plate.

1 is a circuit diagram of a magnetic and nonmagnetic combined induction heating cooker according to the prior art.

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

3 is a waveform diagram of a current according to a switching operation of a load selection switching unit applied to FIG. 2.

*** Explanation of symbols for the main parts of the drawing ***

101: rectifier 102: voltage branch

103: heating unit 104: load selection switching unit (Ry)

105: switching unit

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a circuit diagram of a magnetic and nonmagnetic combined induction heating cooker according to the present invention. The rectifying unit 101 rectifies the input AC voltage into a DC voltage and through the rectifying unit 101. A filter inductor Lf for branching a rectified DC voltage and improving a power factor, a voltage branch unit 102 including first and second capacitors Cf1 and Cf2, and a resonant circuit to form the voltage branch unit ( Working coil part Lr consisting of first and second working coils Lr1 and Lr2, which generate heat according to the input voltage branched by 102 and selectively heat a plurality of heating plates according to the load (magnetic / nonmagnetic). And a heating unit 103 provided as a resonance capacitor and a resonance circuit together with the resonance circuit, but are switched according to an external control signal to timely select a load (magnetic / nonmagnetic) of the heating unit 103. Load selection switching unit 104 for heating by , Is switched according to an external control signal has been composed of a first, a second switching element (S1) the switching unit (105) provided with (S2) for powering the heating element 103 to heat the heating plate.

Referring to Figures 2 and 3 attached to the operation and effect of the present invention configured as described above are as follows.

First, when the operation of the magnetic load is described, when the first switching device S1 of the switching unit 105 is turned on while the load selection switching unit 104 is turned off, the heating unit 103 has half the input voltage (Vd). / 2) is applied and the current of the working coil part Lr of the heating part 103 rises by starting resonance.

Thereafter, when the first switching device S1 of the switching unit 105 is turned off before the resonant half-cycle passes, the first and second auxiliary resonance capacitors Ca1 of the first switching device S1 and the second switching device S2 are turned off. (Ca2) and the resonance circuit of the heating unit 103 to perform an auxiliary resonance.

Then, the voltage of the second auxiliary resonance capacitor C2 of the second switching element S2 drops from the input voltage Vd to half Vd / 2, and the first auxiliary resonance capacitor of the first switching element S1 is interposed therebetween. The voltage at C1 rises from half Vd / 2 to the input voltage Vd.

Thereafter, the first antiparallel diode D2 of the second switching element S2 is turned on so that zero voltage is applied to the resonance circuit of the heating unit 103.

Then, resonance continues by the voltage charged in the resonant capacitor Cr of the heating unit 103, and at this time, the second switching element 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.

In this case, when the second switching device S2 of the switching unit 105 is turned off before the resonant half cycle passes, the first and second auxiliary resonance capacitors Ca1 of the second switching device S2 and the first switching device S1 are turned off. (Ca2) and the secondary resonance together with the resonant circuit of the heating unit 103, so that the voltage of the first auxiliary resonance capacitor Ca1 of the first switching element (S1) is half (Vd / 2) of the input voltage (Vd) In the meantime, the voltage of the second auxiliary resonance capacitor Ca2 of the second switching element S2 increases from half Vd / 2 to the input voltage Vd.

Thereafter, the first antiparallel diode D1 of the first switching element S1 is turned on, and an input voltage Vd is applied to the heating unit 103.

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

Then, when the resonance current drops to zero due to the continuous resonance, one cycle of operation is terminated and the same operation is repeated.

3 shows a current waveform diagram of the first working coil Lr of the heating unit 103 during switching according to the switching operation of the load selection switching unit 104.

The magnetic flux is generated by the induced current, and the magnetic flux is connected with the load vessel (not shown), and an eddy current is generated at the bottom of the container.

The load vessel is heated by Joule heat caused by this eddy current.

As described above, the present invention minimizes the cost and volume of the entire system by replacing the high voltage relay for changing the resonant frequency according to the load with the low voltage relay and removing the resonant capacitor while heating the magnetic container. It is effective.

Claims (5)

Voltage branch means for branching the input voltage and improving the power factor; Heating means for generating a resonant circuit and selectively heating a plurality of heating plates according to a load (magnetic / non-magnetic) by generating heat according to an input voltage branched by the voltage branch means; A load selection switching means which forms a resonance circuit together with the resonance circuit and is switched according to an external control signal so as to timely select and load the load (magnetic / non-magnetic) of the heating means; Magnetic and nonmagnetic combined induction heating cooker comprising a switching means for switching in accordance with an external control signal to supply power to the heating means to heat the heating plate. The method of claim 1, The smoothing means is a magnetic and nonmagnetic combined induction heating cooker, characterized in that provided with a filter inductor (Lf) for branching the input voltage and the first, second filter capacitor (Cf1) (Cf2). The method of claim 1, The heating means is a working coil part Lr consisting of first and second working coils Lr1 and Lr2 which form a resonant circuit for operating a non-magnetic load by operating at an input voltage according to the switching operation of the switching means. And a first heating part (Lr1) which forms a resonant circuit together with the first heating part including the resonant capacitor Cr and the resonant circuit, and operates at a voltage input according to a switching operation of the switching means. Magnetic and nonmagnetic combined induction heating cooker, characterized in that provided with a second heating unit consisting of a non-resonant circuit of the. The method of claim 1, The switching means is provided in accordance with an external control signal is provided with the first and second switching elements (S1) (S2) for supplying power to perform the heating operation independently of the first and second heating unit. Magnetic and nonmagnetic combined induction heating cooker. The method of claim 1, The load selection switching means is a magnetic and nonmagnetic combined induction heating cooker, characterized in that the switch is switched in accordance with an external control signal to select the load of the heating means (Ry).

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