KR100242575B1 - Microwave oven - Google Patents

Abstract

The present invention relates to a microwave oven in which a microwave oven having a plurality of magnetrons implements a monitor circuit for stably shutting off a continuous generation of magnetrons even in a power-off condition.

In the microwave oven having first and second oscillation circuit sections for oscillating a plurality of magnetrons, the configuration is connected to a low voltage transformer and a low voltage transformer connected to a power supply terminal, and interlocked with a safety switch of the first oscillation circuit section when opening the door. It is operated and connected to the safety switch of the first oscillation circuit portion to cut off the power supply to the high voltage portion of the first oscillation circuit portion, and the safety switch of the first oscillation circuit portion, interlocked with the safety switch of the second oscillation circuit portion when opening the door. And a fuse connected to a safety switch of the second oscillation circuit part and a safety switch of the second oscillation circuit part to cut off power supply to the high voltage part of the second oscillation circuit part, and one end of which is connected to a power supply terminal.

Description

microwave

The present invention relates to a microwave oven, and more particularly, to a microwave oven in which a monitor circuit for stably shutting off a continuous generation of a magnetron in a microwave oven having a plurality of magnetrons even under a power interruption condition. will be.

In general, a microwave oven is a cooking appliance equipped with a magnetron as a high frequency generator to irradiate food with high frequency generated from the magnetron to move the molecular arrangement of the food to cook food using heat generated at this time. Therefore, the cooking time of the food is closely related to the amount of high frequency generation in the magnetron.

FIG. 1 is an electrical connection diagram of a commercial microwave oven having two magnetrons for increasing the amount of high-frequency generation in the related art. Microwave ovens perform cooking through high frequency oscillation, and a safety switch, which is a power switching means, is provided to prevent leakage of ultra-high frequency caused by the opening of a door during cooking. The magnetron is continuously operated due to a malfunction (short circuit) of the safety switch. A monitor circuit for intermittent high frequency oscillation is provided.

The configuration is that the first oscillation circuit portion 10 for oscillating the first magnetron 14 and the second oscillation circuit portion 20 for oscillating the second magnetron 24 are connected in parallel with respect to the power supply terminal, and the first The low voltage transformer LVT is connected to the oscillation circuit unit 10 for supplying power to the main PCB and all the power devices. In addition, the oscillation circuit units 10 and 20 interlock with the high voltage parts 15 and 25 for supplying the oscillation power to the magnetrons 14 and 24, and the power supply to the high voltage parts 15 and 25 in conjunction with the opening and closing of the microwave oven. When the safety switch (11, 21) and the magnetron (15, 25) is overheated, the thermo switch (TCO1, TCO2) for controlling the power to the high voltage section (15, 25) and the control of the micro The power relay switches 13 and 23 for controlling the output of the magnetrons 14 and 24 by controlling the power to the 15 and 25 and the door are opened due to the malfunction of the safety switches 11 and 21. When the power is supplied to the high voltage parts 15 and 25 continuously, a short circuit is formed to blow the fuses 1 and 2 so that the power supply to the high voltage parts 15 and 25 is cut off.

Among the above-described components, the monitor circuit is provided in each of the oscillation circuit parts 10 and 20, and the first monitor circuit provided in the first oscillation circuit part 10 forms a short circuit in conjunction with the opening of the door. ) And a fuse (fuse1) which is blown when the short circuit is configured by the first monitor switch 12 to cut off power to the first oscillation circuit unit 10, and is provided in the second oscillation circuit unit 20. The second monitor circuit 22 is also interlocked with the opening of the door to form a short circuit, and when the short circuit is configured by the second monitor switch 22, the second oscillation circuit part 20 is melted. It is composed of a fuse (fuse2) for shutting off the power to the furnace.

That is, when the door of the microwave oven is opened, the first safety switch 11 and the second safety switch 21 open a circuit to cut off power to the high voltage parts 15 and 25 primarily. In addition, the monitor switches 12 and 22 form a short circuit in conjunction with the door. However, since the power is cut off by the safety switches 11 and 12, the short circuit by the short circuit does not occur. However, when the first safety switch 11 or the second safety switch 21 is not interlocked with the door open, and the circuit is continuously closed, there is a risk of harmonic leakage due to the oscillation of the magnetrons 14 and 24. Will be. Therefore, in order to prevent this, when the door is opened, the short circuit is configured by the monitor switches 12 and 22. As a result, the fuses fuse 1 and fuse 2 on the circuit are blown to cut off the power supply to the oscillation circuit units 10 and 20.

However, the conventional microwave oven has the following problems.

That is, when the circuit cannot be opened while the door is open due to the failure of the first safety switch 11 of the first oscillation circuit unit 20, the short circuit is configured by the operation of the first monitor switch 12 to fuse the fuse. ) Is brave. Therefore, the power of the microcomputer operating by receiving power from the low voltage transformer (L.V.T) is cut off. The microcomputer is operated by the microcomputer to cut off the power supply of the microcomputer, and the first and second power relays 13 and 23 for controlling the output of the magnetrons 14 and 24 are turned off. Therefore, the oscillation operation of the first and second magnetrons 14 and 24 is stably interrupted. However, the fuse of the second oscillation circuit unit 20 is operated by the operation of the second monitor switch 22 when the circuit cannot be opened while the door is open due to a failure of the safety switch 21 of the second oscillation circuit unit 20. ) Is melted, and the power supply to the second magnetron 24 is cut off. However, the first magnetron 14 is continuously oscillated when the door of the microwave oven is closed regardless of the monitor circuit of the second magnetron 24.

Therefore, the user cooks in a state in which the output of the microwave is reduced, and when cooking is performed by a preset program, problems such as less cooking occur. In addition, since the cooking is continuously performed while the output is reduced, it is difficult for the user to confirm the actual microwave failure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object thereof is to provide a microwave oven having a plurality of magnetrons, wherein when a monitor circuit of at least one of the oscillating circuits for oscillating each magnetron is operated, The present invention provides a microwave oven capable of satisfactorily shutting off power to the entire microwave oven.

1 is an electrical connection diagram of a conventional microwave oven,

2 is an electrical connection diagram of the microwave oven according to the present invention.

* Explanation of symbols for main parts of the drawings

30: first oscillation circuit section 31: first safety switch 32: second monitor switch

33: The first power relay 35: The first high pressure part 36: The first magnetron

40: second oscillation circuit portion 41: second safety switch 42: second monitor switch

43: 2nd power relay 45: 2nd high voltage part 46: 2nd magnetron

L.V.T: Low voltage transformer

In order to achieve the above technical problem, a configuration of the present invention includes: a first oscillation circuit portion for oscillating a first magnetron and a second oscillation circuit portion for oscillating a second magnetron are connected in parallel to a power supply terminal, and the first, The second oscillation circuit part includes first and second high voltage parts for supplying oscillation power to the first and second magnetrons, and first and second powers for interrupting power supply to the first and second high voltage parts when opening the door. When the power is supplied to the first and second high voltage parts by a safety switch and the first and second safety switches, the first and second magnetrons are interrupted to output the first and second magnetrons. A first and a second power relay for controlling the voltage, a monitor circuit for melting the fuse of the circuit stage to cut off the power supply when the first and second safety switches fail to open the circuit when the door is opened; One, A microwave oven comprising a low voltage transformer for supplying power to a microcomputer for operating and controlling a two-power relay, wherein the monitor circuit is connected to the low voltage transformer connected to a power supply and the low voltage transformer, and the first opening is performed. A first safety switch for interlocking with a first safety switch, for disconnecting power supply to the first high voltage part, and connected to the first safety switch, and interlocking with the second safety switch when the door is opened; The second safety switch to cut off the power supply to the second high voltage portion, characterized in that it comprises a fuse connected to the second safety switch and one end thereof is connected to the power supply terminal.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

2 is an electrical connection diagram of a microwave oven according to the present invention, the configuration of which is as follows.

The first oscillation circuit portion 30 for oscillating the first magnetron 36 and the second oscillation circuit portion 40 for oscillating the second magnetron 46 are connected in parallel to the power supply terminal. In addition, the oscillation circuit sections 30 and 40 interlock with the high voltage parts 35 and 45 for supplying the oscillation power to the magnetrons 36 and 46 and the opening and closing of the microwave oven to control the power to the high voltage parts 35 and 45. The safety switches 31 and 41, the magnetrons 36 and 46, and the thermo switches TCO3 and TCO4 for controlling the power to the high voltage parts 35 and 45, The power relays 33 and 43 for controlling the output of the magnetrons 36 and 46 by controlling the power to the high voltage parts 35 and 45, and the magnetrons 36 and 46 are started when the microwave oven door is opened. A low voltage transformer (LVT) for supplying power to the main PCB and the general power device, a first monitor switch 32 of the first oscillation circuit part 30, and a second oscillation circuit part 40. Is connected to the second monitor switch 42 and the monitor fuse 4.

That is, the monitor circuit includes a low voltage transformer LVT connected to receive power regardless of the opening / closing operation of the first safety switch 31, and the first magnetron when the first safety switch 31 is turned on. Switched to (31), the first monitor switch 32, the circuit switch to the second monitor switch 42 in the off operation of the first safety switch 31, the on of the second safety switch 42 A second monitor switch 42 that is switched to the second magnetron 46 during operation, and a circuit switch to the first monitor switch 32 when the first safety switch 31 is turned off; and the second monitor It is composed of a monitor fuse (fuse5) connected to the switch 42 and connected to the power supply terminal. Therefore, the monitor circuit is connected to the low voltage transformer (L.V.T), the first monitor switch 32, the second monitor switch 42, and the monitor fuse (fuse5) to form a short circuit.

That is, when the first safety switch 31 of the first oscillation circuit unit 30 does not block the circuit in a state in which the door of the microwave oven is opened due to a poor contact, the first monitor switch 32 interlocked with the door. The contact of is switched from gh to gi. In addition, the contact of the second monitor switch 42 is switched from l-k to | -j in a state where the contact i of the first monitor switch 32 and the contact of j of the second monitor switch 42 are connected. At this time, the second safety switch 41 of the second oscillation circuit part 40 is in a state where the circuit is interrupted. Therefore, one end is connected to the j stage, and the other end is constituted as a short circuit as a whole through the monitor fuse (fuse 5) connected to the power supply stage. When the short circuit is configured, the monitor fuse (fuse 5) on the monitor circuit is melted and the supply of power to the low voltage transformer (L.V.T) is cut off by the melt of the monitor fuse.

In addition, when the safety switch of the second oscillation circuit portion 40 does not block the circuit in the state in which the door of the microwave oven is opened due to a contact failure, the contact point of the first monitor switch 32 interoperating with the door is at gh. switch to gi. In addition, the contact of the second monitor switch 42 is switched from l-k to | -j in a state where the contact i of the first monitor switch 32 and the contact of j of the second monitor switch 42 are connected. Accordingly, the current applied through the fuse 4 of the second oscillation circuit part 40 is sequentially applied to the shorted second safety switch 41, the second monitor switch 42, and the monitor fuse 5 to monitor. The fuse 5 is blown. Accordingly, the power supply to the low voltage transformer L.V.T is cut off. That is, when the safety switches 31 and 41 of any one of the first oscillation circuit section 30 and the second oscillation circuit section 40 do not block the circuit in the state that the door of the microwave oven is opened due to a contact failure, a short circuit occurs. The circuit is constructed so that the monitor fuse (fuse5) is blown to cut off the power supply to the low voltage transformer (LVT). Therefore, the microcomputer operating by being supplied with power by the low voltage transformer (L.V.T) also stops operating. When the microcomputer stops operating, the power relays 43 of the first oscillation circuit unit 30 and the second oscillation circuit unit 40 which are switched by the control of the microcomputer are turned off to the high voltage units 35 and 45. The power supply is cut off and the oscillation of the magnetrons 36 and 46 is also stopped.

As described above in detail, according to the present invention, when the monitor circuit is operated in any one of the oscillation circuit portions in the microwave oven having the oscillation circuit for driving the plurality of magnetrons, by stably shutting off the power of the entire microwave oven, 2 It is possible to prevent accidents that may occur in the future.

Claims (1)

The first oscillation circuit portion for oscillating the first magnetron and the second oscillation circuit portion for oscillating the second magnetron are connected in parallel to the power supply terminal, and the first and second oscillation circuit portions are connected to the first and second magnetrons. The first and second high pressure parts for supplying the oscillation power, the first and second safety switches for interrupting the power supply to the first and second high pressure parts when the door is opened, and the first and second safety switches. First and second power relays for controlling the outputs of the first and second magnetrons by intermittent power to the first and second high voltage parts when power is supplied to the first and second high voltage parts by means of: When the first and second safety switches fail to open the circuit when the door is opened, a monitor circuit that blows the fuse of the circuit stage and cuts off the power supply, and a microcomputer for operation control of the first and second power relays. Power ball In a microwave oven configured with a low-voltage transformer for urgent, The monitor circuit includes the low voltage transformer connected to a power supply terminal; A first safety switch connected to the low voltage transformer, interlocked with the first safety switch when the door is opened, and interrupting power supply to the first high voltage unit; A second safety switch connected to the first safety switch, the second safety switch interlocked with the second safety switch when the door is opened, and for interrupting power supply to the second high pressure part; And And a fuse connected to the second safety switch and one end of which is connected to a power supply terminal.

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