KR20010058107A - Power Circuit For DC Microwave Oven - Google Patents

Abstract

PURPOSE: A power supply circuit of a DC microwave oven is provided to be useful for the power supply of external electronic equipment by forming an additional AC power outlet to a DC power circuit of a microwave oven. CONSTITUTION: A DC power circuit includes: a DC power unit(2) generating DC voltage; a switching circuit(4) switched on/off to supply the DC voltage and to cook; an inverter circuit(6) converting the DC voltage into AC; and a magnetron drive circuit(10) for driving a magnetron(12). An HVT(High Voltage Transformer,14) is terminated to AC voltage through a primary coil(14a) while generating high voltage proportional to a winding ratio with the primary coil at secondary coils(14b,14c). A rated AC voltage of 220V is terminated in proportion to a winding ratio with the primary coil at an AC induction coil(14d) of the HVT. To cook with a microwave oven, a first and a second relay(RL1,RL2) are switched on while a third relay(RL3) is switched off. Thereby, the magnetron drive circuit is driven by high pressure at the secondary coil through the switched-on second relay. The magnetron generates microwaves by driving the magnetron drive circuit as the first relay is switched on.

Description

Power Circuit For DC Microwave Oven

The present invention relates to a power supply circuit of a direct current microwave oven, and more particularly, to a power supply circuit of a direct current microwave oven for drawing out a rated AC voltage to the outside of the microwave oven.

In general, microwave ovens are commercially available such that microwave ovens are designed to drive a magnetron by converting a rated commercial AC power supply into a high voltage. On the other hand, since such an AC microwave oven is designed to be driven using only a commercial AC power supply, there is a problem in that it is difficult to use in various transportation means or outdoor where supply of AC power is difficult.

In order to solve such a problem, in recent years, a microwave oven has been developed with an inverter for converting a DC voltage from an AC power source such as a vehicle, or a DC power source such as a battery power source that can be carried outdoors. It is used.

1 is a view showing a power supply circuit of a conventional microwave oven. As shown in FIG. 1, a conventional microwave oven includes a DC power supply 2, a switching circuit 4, an inverter circuit 6, a high voltage transformer 8, a magnetron driving circuit 10, and a magnetron ( 12).

The switching circuit 4 includes a door detection switch for detecting a state in which the cooking chamber door of the microwave oven is opened and closed, a primary interlock switch, and a secondary interlock switch switched according to the start of the cooking function. .

Here, when the door lock switch and the master lock switch of the switching circuit 4 are switched to operate in the state in which the cooking chamber door is closed, and the non-stop lock switch is switched according to the start of the predetermined cooking function, from the DC power supply 2 The DC voltage of is converted into an AC voltage by the drive of the inverter circuit 6.

On the other hand, the inverter circuit 6, as shown in the patent application No. 99-40702 filed by the applicant of September 21, 1999 (magnetron drive circuit of the AC / DC microwave oven), the push-pull circuit ( Push Pull Circuit) is preferably applied.

In addition, the inverter circuit 6, as shown in the patent application No. 99-40701 filed by the applicant of September 21, 1999 (AC / DC combined microwave oven capable of acquiring AC voltage), AC It is also possible to employ a rotary inverter as the converting means.

However, the technology of the push-pull circuit and the rotary inverter employed in the inverter circuit 6 and the magnetron driving circuit using the push-pull circuit and the rotary inverter are not yet disclosed and do not correspond to publicly known technologies. Do not.

Further, the high voltage transformer 8 is connected to the respective winding ratios through the secondary coils 8b and 8c in a state in which an AC voltage is induced in the primary coil 8a by driving the inverter circuit 6. AC voltage of proportional high voltage is generated.

The magnetron driving circuit 10 includes a high voltage diode and a high voltage capacitor, and backs up the high pressure induced in the secondary coil 8c of the high voltage transformer 8 to supply the magnetron 12. Therefore, the magnetron 12 receives microwaves generated through the magnetron driving circuit 10 to generate microwaves.

In the microwave oven configured as described above, the DC voltage from the DC power supply 2 is converted from the high voltage transformer 8 into an AC voltage by the drive of the inverter circuit 6, and the high voltage is applied by the high voltage transformer 8. After the conversion to the magnetron 12 is driven.

However, in such a conventional microwave oven, since the AC voltage converted from the DC power supply by the AC conversion means is used only for the function of driving the magnetron to perform the cooking operation, the AC voltage other than the DC microwave oven is used. In order to use other external electronic devices that require the supply of, since an AC converter for converting the DC power source to AC is separately provided, there is a disadvantage that an additional cost is inevitable.

Therefore, in recent years, the addition of a new function that makes it possible to easily supply the AC voltage to other external electronics by using the AC conversion function of the DC power provided in the microwave oven for DC.

The present invention has been made in view of the above-described conventional circumstances, and an object thereof is to form a separate AC power outlet circuit in a power circuit of a microwave oven for use in supplying operating power to an external electronic device. It is to provide a power supply circuit of a direct current microwave oven.

1 is a view showing a power circuit of a conventional direct current microwave oven,

2 is a view showing a power circuit of a microwave oven for direct current according to the first embodiment of the present invention;

3 is a view showing a power supply circuit of the microwave oven for DC according to the second embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

2: DC power supply, 4: switching circuit,

6: inverter circuit, 8,14: high voltage transformer,

10: magnetron drive circuit, 12: magnetron,

16: Auxiliary transformer, RL1 to RL4: Power supply relay.

In order to achieve the above object, according to the power supply circuit of the microwave oven for direct current according to the first embodiment of the present invention, an inverter circuit for converting the voltage of the DC power supply into alternating current, and the voltage converted into alternating current by the inverter circuit In the power supply circuit of a direct current microwave oven having a high voltage transformer having a primary coil and a secondary coil, and a magnetron driven by the high voltage of the high voltage transformer for boosting the voltage, the voltage converted into alternating current by the inverter circuit Provided is a power supply circuit for a microwave oven provided with a means for generating an alternating rated AC voltage and an AC drawing means for drawing out the rated AC voltage generated by the rated AC voltage generating means to the outside. .

Preferably, the rated AC voltage generating means is composed of an AC drawing coil which is installed on the secondary side of the high voltage transformer and induces an alternating AC voltage proportional to the winding ratio with the primary coil. This corresponds to an AC drawing terminal extending from both ends of the drawing coil.

More preferably, the AC drawing terminal is configured to be connected to a power outlet that can connect a plug of an external electronic device.

In addition, a power relay for controlling the drawing state of the rated AC voltage is additionally connected between the rated AC voltage generating means and the AC drawing means, and an execution state of a cooking function is provided between the secondary side of the high voltage transformer and the magnetron. An intermittent power supply relay is additionally connected.

In addition, the rated AC voltage generating means includes a primary coil in which the AC voltage converted by the drive of the inverter circuit is induced, and a secondary coil generating a rated AC voltage in proportion to the winding ratio of the primary coil. A power supply relay configured to be an auxiliary transformer, and additionally connected between the inverter circuit and the primary coil of the auxiliary transformer to interrupt a state in which the rated AC voltage of the auxiliary transformer is induced, is additionally connected.

According to the present invention configured as described above, in a microwave oven for driving a magnetron by converting a DC voltage from a DC power source into an AC by an AC conversion means, the AC voltage converted by the AC conversion means As the device converts into AC voltage of usable rating and supplies it to the outside, it is possible to supply the AC voltage of the rating provided by the microwave itself to an external electronic device without installing a separate AC converter outside. .

Hereinafter, the present invention configured as described above will be described in detail with reference to the accompanying drawings.

2 is a view showing a power supply circuit of the microwave oven for DC according to the first embodiment of the present invention.

As shown in Fig. 2, according to the power supply circuit of the microwave oven according to the first embodiment of the present invention, the DC power source 2 generates a DC voltage and the DC voltage from the DC power source 2 is generated. A switching circuit 4 which is switched for execution of a supply and cooking function, an inverter circuit 6 for converting a DC voltage from the DC power supply 2 into AC, and a magnetron driving circuit 10 for driving the magnetron 12. ) Is the same as the configuration for a conventional microwave oven.

However, the main feature of the power supply circuit of the direct-current microwave oven according to the first embodiment of the present invention is that the high-voltage transformer 14 is the primary side coil 14a in which an AC voltage is induced by the drive of the inverter circuit 6. And the secondary-side coil 14d is additionally configured on the secondary side, in addition to the secondary side coils 14b and 14c in which high pressure is induced in proportion to the winding ratio with the primary-side coil 14a. Is the point.

Here, the AC drawing coil 14d of the high voltage transformer 14 is predetermined with the primary coil 14a in order to induce an AC power supply rated at, for example, 220V, which can be used in other external electronic devices. The turns ratio of is set.

The AC lead-out coil 14d has an AC outlet terminal extending from both ends thereof, and it is preferable to connect a power outlet CON to the AC outlet terminal so that a plug of an external electronic device can be connected thereto. Do.

Meanwhile, a first power supply relay RL1 is connected between the secondary coil 14b of the high voltage transformer 14 and the connection terminal of the magnetron 12, and the secondary coil 14c and the magnetron driving circuit are connected to each other. A second power supply relay RL2 is interposed between the connection terminals of 10. A third power supply relay RL3 is connected between the AC drawing coil 14d and the AC drawing terminal.

The first to third power supply relays RL1 to RL3 may be individually or integrally switched and controlled by a single relay switch circuit, but may correspond to the first to third power supply relays RL1 to RL3, respectively. It is also good to provide a plurality of relay switch circuit to be made to the individual switching control. Further, the first to third power supply relays RL1 to RL3 preferably employ an electrically operated semiconductor element, but a mechanically operated switch may be employed.

Next, the operation of the present invention made as described above will be described in detail with reference to FIG.

First, in the state in which the inverter circuit 6 receives the DC voltage from the DC power supply 2 through the switching circuit 4 and converts it into an AC voltage, the high voltage transformer 14 passes through the primary coil 14a. The AC voltage is induced and the secondary coils 14b and 14c generate a high pressure proportional to the turns ratio with the primary coil 14a.

On the other hand, in the AC drawing coil 14d of the high voltage transformer 14, an AC voltage rated at, for example, 220V is induced in proportion to the winding ratio with the primary coil 14a.

In this state, when only the cooking function of the microwave is to be implemented, the first and second power supply relays RL1 and RL2 are switched and connected to each other during the first to third power supply relays RL1 to RL3. The power supply relay RL3 is switched open.

Accordingly, the magnetron driving circuit 10 is driven by being supplied with a high voltage induced in the secondary coil 14c of the high voltage transformer 14 through the second power supply relay RL2 in a switched connection state, and the magnetron 12 is driven. Generates microwaves by driving the magnetron driving circuit 10 in the switching connection state of the first power relay RL1.

On the other hand, when the AC power source is to be drawn to an external predetermined electronic device instead of interrupting the execution of the cooking function of the microwave oven, the first and second power sources among the first to third power supply relays RL1 to RL3. The relays RL1 and RL2 are switched open, while the third power supply relay RL3 is switched connected.

Accordingly, the magnetron driving circuit 10 does not receive high voltage induced by the secondary coil 14c of the high voltage transformer 14 according to the switching open state of the second power relay RL2. The magnetron 12 is stopped, and microwaves are not generated according to the driving stop state of the magnetron driving circuit 10.

However, in the AC drawing terminal connected to the AC drawing coil 14d of the high voltage transformer 14, the AC voltage of the rating induced in the AC drawing coil 14d is switched according to the switching connection of the third power supply relay RL3. It is authorized.

On the other hand, when a power outlet to which a plug of a predetermined external electronic device is connected is connected to the AC drawing terminal, the AC voltage rated from the AC drawing terminal can be supplied to the external electronic device side by the outlet and the plug. Can be.

However, in the case where the cooking function of the microwave oven is to be executed simultaneously with the AC power supply drawing function to the outside, the first to third power supply relays RL1 to RL3 may maintain the switching connection state.

Next, a second embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a view showing a power supply circuit of the microwave oven for DC according to the second embodiment of the present invention.

As shown in FIG. 3, according to the power supply circuit of the microwave oven according to the second embodiment of the present invention, the secondary coils 8b and 8c of the high voltage transformer 8, the magnetron driving circuit 10, and the magnetron (12) is connected between the first power supply relay RL1 and the second power supply relay RL2, respectively, and connected to the AC lead-out terminal via the third power supply relay RL3. One configuration is the same as the first embodiment of the present invention.

However, in the second embodiment of the present invention, the primary coil 16a connected to both ends of the primary coil 8a of the high voltage transformer 8, apart from the high voltage transformer 8, and the primary coil 16 An auxiliary transformer 16 having a secondary side coil 16b for converting an AC voltage induced in 16a into a rated AC voltage is configured. In addition, a fourth power supply relay RL4 is connected between the inverter circuit 6 and the connecting end of the primary coil 16a of the auxiliary transformer 16.

Here, a predetermined turns ratio of the primary coil 16a and the secondary coil 16b of the auxiliary transformer 16 is set such that an AC voltage rated at, for example, 220V can be drawn out.

On the other hand, the fourth power supply relay RL4 is preferably provided to be individually or integrally switched and controlled by the first to third power supply relays RL1 to RL3 and a single relay switch circuit. It is also possible to form a relay switch circuit separate from the relay switch circuit for switching the third power source relays RL1 to RL3 to perform individual switching control.

In addition, since the fourth power supply relay RL4 is connected for switching control of the AC voltage induced state of the auxiliary transformer 16, the third power supply relay RL3 connected to the rear end of the auxiliary transformer 16 is further connected. ) May be omitted.

According to the power supply circuit of the direct current microwave oven according to the second embodiment of the present invention made as described above, when only the cooking function of the microwave oven is to be performed, the first and second power supply relays RL1 and RL2 are connected to each other. By driving the magnetron driving circuit 10, the microwaves are generated in the magnetron 12. In addition, the third and fourth power supply relays RL3 and RL4 may be switched open so that an AC voltage is not induced in the auxiliary transformer 16.

On the other hand, when it is desired to supply the rated AC voltage to a predetermined external electronic device instead of interrupting the execution of the cooking function, the third and fourth power supply relays RL3 and RL4 are switched and connected to each other. The rated AC voltage induced in the secondary coil 16b of the transformer 16 is drawn to the AC lead-out terminal side.

Therefore, when an outlet to which a plug of a predetermined external electronic device is connected is connected to the AC outlet terminal, the rated AC voltage from the AC outlet terminal can be supplied to the external electronic device side by the outlet and the plug. .

According to the present invention made as described above, by forming a separate AC drawing circuit for supplying an AC voltage to the external electronic device side in a microwave oven for converting DC power into AC by employing an inverter means, It is possible to supply AC voltage to the external electronic device by using the AC conversion function inside the microwave without having an AC conversion device, which can reduce the additional cost. It will have the effect that it can provide consumers with the convenience of the new concept.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes are intended to fall within the scope of the claims set forth.

Claims (8)

An inverter circuit for converting a voltage of a direct current power source into an alternating current, a high voltage transformer having a primary coil and a secondary coil for boosting the voltage converted into alternating current by the inverter circuit, and a magnetron driven by the high voltage of the high voltage transformer. In the power supply circuit of the microwave oven provided, Means for receiving a voltage converted into alternating current by the inverter circuit and generating a rated alternating voltage; And an AC drawing means for drawing out an AC voltage of the rating generated by the rated AC voltage generating means to the outside. 2. The direct current generator according to claim 1, wherein the rated AC voltage generating means is constituted by an AC drawing coil which is installed on the secondary side of the high voltage transformer and induces an AC voltage rated in proportion to the winding ratio with the primary coil. Microwave power supply circuit. 3. The power supply circuit of a microwave oven according to claim 2, wherein the AC drawing means is an AC drawing terminal extending from both ends of the AC drawing coil. 4. The power supply circuit of a microwave oven according to claim 3, wherein a power supply outlet for connecting a plug of an external electronic device is connected to the AC drawing terminal. 2. The power supply circuit of a microwave oven according to claim 1, wherein a power relay for controlling a drawing state of the rated AC voltage is additionally connected between the rated AC voltage generating means and the AC drawing means. The power supply circuit of a microwave oven according to claim 1, wherein a power relay for controlling an execution state of a cooking function is further connected between the secondary side of the high voltage transformer and the magnetron. 2. The rated AC voltage generating means according to claim 1, wherein the rated AC voltage generating means generates a rated AC voltage in proportion to a winding ratio between the primary coil in which the AC voltage converted by the drive of the inverter circuit is induced and the primary coil. A power supply circuit for a direct current microwave oven, comprising: an auxiliary transformer having a side coil. 8. The power supply circuit of a direct current microwave oven according to claim 7, wherein a power supply relay for controlling a state in which the rated AC voltage of the auxiliary transformer is induced is additionally connected between the inverter circuit and the primary coil of the auxiliary transformer.