KR20040005292A - Driving apparatus for microwave oven - Google Patents

Abstract

PURPOSE: A driving device for a microwave oven is provided to generate the microwave energy by switching the low DC power to output the high voltage and large current. CONSTITUTION: A driving device for a microwave oven includes a power supply(1), a capacitor(2), an inverter(3), a HVT(High Voltage Transformer)(4), a MGT(5), and a controller. The power supply(1) is used for supplying the low DC power. The capacitor(2) is used for smoothing the low DC power of the power supply(1). The inverter(3) is used for switching the low DC power of the power supply(1). The HVT(4) is used for receiving the output signal of the inverter(3) and outputting the high voltage. The MGT(5) is used for rectifying the high voltage of the HVT(4) and generating the electromagnetic waves. The controller is used for controlling a switching operation of the inverter(3).

Description

Drive of microwave oven {DRIVING APPARATUS FOR MICROWAVE OVEN}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a microwave oven, and more particularly, to a drive device for a microwave oven that generates electromagnetic waves using a LOW DC power source.

In general, a microwave oven obtains a second high voltage by directly applying a commercial AC power source (AC) to a primary side of an iron core type HVT (high voltage transformer).

The operating principle of the microwave oven is that when the cathode filament provided in the magnetron is heated and a high voltage of about 4,000 volts is applied, the magnetron oscillates to radiate microwave energy.

The microwave energy is converted into thermal energy when it meets an object (ie, food ingredients, etc.) containing moisture or moisture in a closed space, and cooking can be performed by the characteristics of the microwave oven.

1 is a circuit diagram schematically showing the configuration of a conventional microwave oven. As shown in the figure, the conventional microwave oven is a power supply 51, the HVT 53 for generating a high voltage by the power supplied through the power supply, and the high voltage generated in the HVT 53 MGT device 55 for heating the food contained in the cooking chamber of the microwave by generating electromagnetic waves, a relay 57 for controlling the supply of voltage and frequency on and off, and a power supply device 51. The control unit 59 controls the HVT 53, the MGT device 55, and the relay 57 when the power is supplied from the power supply.

By such a configuration, when power is supplied from the power supply device 51 and the relay 57 is energized by the control of the control unit 59, current flows to the primary side of the HVT 55, whereby HVT ( 55) Voltage is induced on the secondary side.

At this time, the secondary winding of the HVT 55 is provided with a voltage of several volts for heating the filament of the MGT device 55 and thousands of volts for the oscillation of the MGT device.

On the other hand, since the direct current should be applied to the cathode of the MGT apparatus 55, rectification and smoothing means for performing rectification and smoothing are provided.

That is, the above-described conventional apparatus applies a DC 4KV power supply, which rectifies the AC voltage of the HVT to a double voltage using a commercial AC power supply, to a MGT device that generates microwaves, and thereby applies electromagnetic energy generated by the MGT device. To cook food.

Here, since the conventional apparatus described above uses a commercial AC power source, there is a problem in that it is not possible to cook food in the open air without a commercial AC power source or in a power-free state such as a power failure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a driving apparatus of a microwave oven to drive microwaves by generating microwave energy using a widely used LOW DC power source. .

1 is a circuit diagram schematically showing the configuration of a conventional microwave oven.

Figure 2 is a circuit diagram showing the configuration of one embodiment of a drive device of the present invention microwave oven.

3 is a switching current waveform diagram in FIG. 2;

4 is a circuit diagram of an embodiment showing the configuration of an inverter section in FIG.

Fig. 5 is a diagram of current waveforms of respective parts in Fig. 4;

Figure 6 is a circuit diagram of an embodiment showing the configuration of the inverter in Figure 2;

Fig. 7 is a diagram of current waveforms of respective parts in Fig. 6;

***** Description of the symbols for the main parts of the drawings *****

1: power supply unit 2: smoothing capacitor

3: inverter portion 4: HVT

5: MGT

The present invention for achieving the above object, the power supply for supplying a LOW DC power supply; A smoothing capacitor for smoothing a LOW DC power supply of the power supply unit; An inverter unit receiving the LOW DC power of the power supply unit and switching the same; An HVT generating a high voltage by receiving a signal output from the inverter; MGT for receiving the high voltage generated by the HVT rectified by half-wave double voltage and generates an electromagnetic wave; For generating electromagnetic waves, it characterized in that it comprises a control unit for controlling the switching of the inverter unit.

Hereinafter, with reference to the accompanying drawings, the operation and effects of the driving apparatus of the microwave oven according to the present invention will be described in detail.

Figure 2 is a block diagram showing an embodiment of a drive device of the microwave oven of the present invention, a power supply unit 1 for supplying a LOW DC power as shown therein; A smoothing capacitor (2) for smoothing the LOW DC power of the power supply (1); An inverter unit 3 receiving the LOW DC power of the power supply unit 1 and switching the same; An HVT 4 receiving a signal output from the inverter unit 3 to generate a high voltage; MGT (5) for receiving the high voltage generated by the HVT (4) by rectifying the half-wave double voltage to generate an electromagnetic wave; In order to control the amount of electromagnetic wave generation, a control unit (not shown) for controlling the switching of the inverter unit 3 is provided, and the operation of the present invention will be described.

First, when the LOW DC power is supplied from the power supply unit 1 and the switching elements S1 and S2 of the inverter unit 3 are energized by the control of a controller (not shown), a current is supplied to the primary side of the HVT 4. Flows, thereby inducing a 4KV DC voltage on the secondary side of the HVT 4.

That is, the secondary winding of the HVT 4 is provided with a voltage of several volts for heating the filament of the MGT (5) and thousands of volts for the oscillation of the MGT (5).

Subsequently, the MGT receives the 4KV DC voltage induced at the secondary side of the HVT 4 by rectifying the half-wave double voltage to generate electromagnetic waves, and the food is cooked by the electromagnetic waves.

Here, the inverter unit 3 is connected to the primary coil of the HVT 24 as shown in FIG. 2, and under the control of a controller (not shown), resonates the magnitude of the LOW DC power supply to the secondary coil of the HVT. Enter it.

In this case, the inverter unit 3 is configured by connecting two switching elements in parallel because the switch peak current is high, and the two switching elements S1 and S2 respectively prevent reverse current between the collector and the emitter stage. It is an ENP transistor with a diode attached.

3 is a waveform diagram of the switching current.

In addition, the inverter unit 3-1 may be configured as a half bridge circuit by connecting two switching devices S1 and S2 in series, as shown in FIG. 4. The two switching devices S1 and S2 may be used. Are NMOS transistors each having a reverse current prevention diode and a capacitor between a drain and a source.

That is, the inverter unit 3-1 is supplied with the current as shown in FIG. 5A through the smoothing capacitor 2 through the LOW DC power supply of the power supply unit 1, and controlled by a controller (not shown). As a result, when the switching elements S1 and S2 of the inverter unit 3-1 are energized as shown in Fig. 5C, a current as shown in Fig. 4B flows to the primary side of the HVT 4, As a result, a 4KV DC voltage is induced on the secondary side of the HVT 4.

In addition, the inverter unit 3-2 may be configured as a series resonant full bridge circuit using four switching elements S1 to S4 as shown in FIG. 6. The four switching elements S1 to S4 may be configured. ) Are NMOS transistors with a reverse current prevention diode and a capacitor between the drain and the source, respectively.

That is, the inverter unit 3-2 is supplied with the current as shown in FIG. 7A through the smoothing capacitor 2 to supply the LOW DC power of the power supply unit 1 to the control of the controller (not shown). As a result, when the switching elements S1 to S4 of the inverter unit 3-2 are energized as shown in Fig. 7C, a current as shown in Fig. 7B flows to the primary side of the HVT 4, As a result, a 4KV DC voltage is induced on the secondary side of the HVT 4.

In other words, the inverter unit generates a high voltage through semiconductor oscillation, and the magnitude of the high voltage obtained here can be freely increased or decreased by varying a control signal (oscillation frequency) of the controller, that is, by lowering the oscillation frequency output from the controller. As the resonance current increases, the secondary high voltage increases, and when the oscillation frequency is increased, the secondary high voltage decreases.

That is, the low-voltage power supply, not the commercial AC power supply, is boosted by the inverter device, and the food is cooked by generating a microwave with a DC 4KV power supply in which the power of the HVT induced by the boosted power supply is double-pressure rectified.

The specific embodiments or examples made in the detailed description of the present invention are intended to clarify the technical contents of the present invention to the extent that they should not be construed as limited to these specific embodiments and should not be construed in consultation. Various changes can be made within the scope of.

As described in detail above, the present invention converts a LOW DC power source widely used into high voltage and high current switching to a DC 4KV power supply, thereby generating microwave energy using the DC 4KV power supply, regardless of location constraints or power supply. There is an effect of driving the range.

Claims (7)

A power supply unit for supplying LOW DC power; A smoothing capacitor for smoothing a LOW DC power supply of the power supply unit; An inverter unit receiving the LOW DC power of the power supply unit and switching the same; An HVT generating a high voltage by receiving a signal output from the inverter; MGT for receiving the high voltage generated by the HVT rectified by half-wave double voltage and generates an electromagnetic wave; In order to generate electromagnetic waves, a drive device for a microwave oven comprising a control unit for controlling the switching of the inverter unit. The method of claim 1, wherein the inverter unit, The first and second switching elements connected in parallel to each other, the on / off control by the control signal of the control unit, characterized in that the driving device of the microwave oven. The method of claim 2, wherein the first and second switching elements, A drive device for a microwave oven, characterized in that each of the NPE transistors with a reverse current prevention diode attached between the collector and the emitter stage. The method of claim 1, wherein the inverter unit, The first and second switching device is connected to the series resonant half-bridge, the on and off control by the control signal of the control unit. The method of claim 4, wherein the first and second switching elements, Each of the driving device of the microwave oven, characterized in that the NMOS transistor with a reverse current prevention diode and a capacitor between the drain and the source. The method of claim 1, wherein the inverter unit, It is connected to the series resonant type full bridge, the driving device of the microwave oven, characterized in that the first to fourth switching elements which are controlled on and off by the control signal of the control unit. The method of claim 6, wherein the first to fourth switching elements, Each of the driving device of the microwave oven, characterized in that the NMOS transistor with a reverse current prevention diode and a capacitor between the drain and the source.