KR20050001714A - Microwave Oven And Method Of Controlling The Same - Google Patents

Abstract

PURPOSE: A microwave oven and a control method thereof are provided to reduce the size of the electric component by cooling the high voltage transformer continuously in cooking and stopping cooking. CONSTITUTION: A microwave oven comprises an electric component formed in a machine room to generate high frequency, a blower fan cooling the electric component by blowing external air, a fan driving unit operating the blower fan, and a controller(54) driving the blower fan by controlling the fan driving unit in stopping cooking. The fan driving unit is composed of a fan motor(26) and a motor relay(28), and the blower fan is driven for the predetermined time by the controller. The motor relay supplies driving power to the fan motor by the controller, and the fan motor drives the blower fan in supplying power. The electric component includes a high voltage transformer(42) and a magnetron(50), and the high voltage transformer boosts input voltage to apply high voltage to the magnetron.

Description

Microwave Oven and its Control Method {Microwave Oven And Method Of Controlling The Same}

The present invention relates to a microwave oven having a blowing fan for preventing overheating and a control method thereof.

Microwave ovens are equipped with a blower fan to cool the electrical components because the heat generated by the high-temperature transformer, magnetron, such as high temperature heat. Blower fans are usually installed at the rear of the machine room to allow outside air to flow into the machine room where the electrical components are installed.

In order to effectively dissipate heat generated from the high voltage transformer, it is good to increase the total size of the high voltage transformer. However, if the size of the high-voltage transformer is increased, the occupancy area is increased, which is a burden on the miniaturization of the product, and also increases the manufacturing cost.

The blowing fan is operated in conjunction with the cooking operation, and usually drives the blowing fan at the start of cooking and stops the driving of the blowing fan at the end of cooking.

However, in the conventional microwave oven, the cooking may be stopped while cooking by driving the magnetron. For example, when the user cuts the driving power to stop cooking, such as when a user operates a pause key and a cancel key, the blowing fan is also stopped. That is, when the cooking was stopped, the blowing fan was not driven.

As the cooling effect of the high pressure transformer by the blowing fan is better, it is advantageous to miniaturize the high pressure transformer. Therefore, a method of miniaturizing the high pressure transformer is required by performing the cooling operation of the high pressure transformer by the blowing fan more efficiently. .

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 microwave oven and a control method thereof to improve the control of the blower fan to reduce the size of the high-voltage transformer.

1 is an electrical circuit of a microwave oven according to the present invention.

2 is a flowchart illustrating a control method of the microwave oven according to the first embodiment of the present invention.

3 is a flowchart illustrating a method for controlling a microwave oven according to a second embodiment of the present invention.

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

26: fan motor

28: motor relay

52: relay drive unit

54: controller

The present invention for achieving the above object is an electrical component provided in the machine room to generate a high frequency, a blowing fan for blowing outside air to cool the electrical component, a fan driving unit for driving the blowing fan, and cooking is stopped If it is characterized in that it comprises a controller for controlling the fan driving unit to drive the blowing fan.

The fan driving unit includes a fan motor and a motor relay, the motor relay supplies driving power to the fan motor under control of the controller, and the fan motor drives the blower fan when power is supplied.

The controller drives the blower fan for a set time.

The electrical component includes a high voltage transformer and a magnetron, and the high voltage transformer boosts an input voltage to apply a high voltage to the magnetron.

In order to achieve the above object, the present invention determines whether a cooking stop command is input during cooking using an electrical component such as a high voltage transformer and a magnetron, and when a cooking stop command is input, cuts off driving power supplied to the electrical part. Cooking is stopped and cooling of the electrical components is performed.

Cooling on the electrical components drives the blower fan to blow outside air.

The driving time of the blowing fan is counted and the blowing fan is stopped when the counted time reaches the first set time.

The driving time of the magnetron to be driven for cooking is counted and the blower fan is driven when the counted time reaches the second set time.

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

1 is a circuit diagram of a microwave oven according to the present invention.

The microwave oven according to the present invention is connected to a power cord 10 and a power cord for providing a commercial AC power supply to the filter unit 12, the magnetron 50 to remove the noise included in the power supply voltage to provide a high voltage For this purpose, a high voltage transformer 42 for boosting and outputting an input voltage is provided. In addition, the present invention is the first temperature sensor 14, the second temperature sensor 16, the safety switch 20, the monitor switch to the power line connecting the output side of the filter unit 12 and the input side of the high-voltage transformer 42 40) and the power relay 36 is connected. The lamp 22 and the lamp relay 24 are connected in series between the safety switch 20 and the power relay 36, and the fan motor 26 and the motor relay 28 are connected in series. The drive motor 30 is connected between the intermediate tap of the fan motor 26 and the motor relay 28. The fan motor 26 drives the blower fan to cool the electrical components including the high voltage transformer. The drive motor 30 drives the cooking dish installed in the cooking chamber.

The inrush relay 32 and the relay PTC 34 are connected in parallel to the power relay 36 to prevent inrush current generated at the initial stage of power input.

The low voltage transformer 18 depressurizes the AC power from which the noise is removed by the filter unit 12 to provide a predetermined DC power to each unit.

The first temperature sensor 14 is turned on and off to cut off the driving power according to the temperature of the magnetron, the second temperature sensor 16 is turned off to cut off the driving power according to the temperature of the cooking chamber, the safety switch 20 ) Is turned on and off to cut off the driving power according to the door opening and closing.

The monitor switch 40 is operated opposite to the safety switch when the safety switch is broken to form a short circuit.

The high voltage fuse 44, the high voltage capacitor 46, and the high voltage diode 48 are connected between the high voltage transformer 42 and the magnetron 50.

The present invention also includes a controller 54 for controlling the overall operation of the microwave oven. An input unit 56 for inputting various operation commands from a user is connected to an input terminal of the controller, and a relay driver 52 for driving relays including a lamp relay 24 and a motor relay 28 is connected to an output terminal of the controller. do.

The controller 52 turns off the power relay 36 when a cooking stop command, for example, a pause command or a cancel command is input through the input unit during cooking. Accordingly, the power applied to the primary coil of the high voltage transformer 42 is cut off and the driving of the magnetron 50 is eventually stopped. At this time, the controller 52 continues to drive the fan motor 26 by turning on the motor relay 28 even when a cooking stop command is input, and maintains the drive of the fan motor 26 for a set time. As a result, even when the cooking is interrupted, the cooling of the electrical components including the high-voltage transformer is continued.

A control method of the microwave oven according to the present invention having the above configuration will be described with reference to the accompanying drawings.

2 is a flowchart illustrating a control method of the microwave oven according to the first embodiment of the present invention.

The user sets a desired cooking condition via the input unit 56 (60). The controller 54 receives an input command by the user and determines whether the input command is cooking start (62). When the input command for the cooking start is input, the controller 54 controls the relay driver 52 to turn on the inrush relay 32 and the power relay 36 in order to drive the magnetron 50 and the motor. The relay 28 is turned on to drive the fan motor 26. Accordingly, the cooking is made and the blowing fan is operated by the fan motor (64).

During cooking, the controller 54 determines whether a cooking stop command is input through the input unit 56 (66), and when the cooking stop command is input as a result of the determination, the controller 54 controls the relay driver 52. The power relay 36 is turned off while the motor relay 28 is turned on. Accordingly, the driving of the magnetron is stopped, but the cooling action by the blower fan is continued by the driving of the fan motor 26 (68). At this time, the controller 54 counts the driving time of the blowing fan using the internal counter (70), and determines whether the counted time reaches the first predetermined time. Here, the first preset time is approximately 1 minute (72).

If it is determined that the counted time has not reached the first set time, the process returns to operation 68 to continue to operate the blower fan.

As a result of the determination, the determination returns to operation 66 when the counted time reaches the first preset time.

When the cooking stop command is not input as a result of the determination of operation 66, the controller 54 determines whether the cooking is completed according to the elapse of cooking time (67), and if the cooking is not the cooking end, the cooking process continues to cook. Return to operation 64.

As a result of the determination, when the cooking ends, the controller 54 controls the relay driver 52 to turn off the power relay 36 and to turn off the motor relay 28. Accordingly, the driving of the magnetron is stopped, the cooking operation is finished, and the blowing fan is stopped (69).

In the above-described first embodiment, when the cooking stop occurs, the magnetron is stopped and the fan motor is continuously driven. On the other hand, when the driving time of the magnetron is longer than the set time, the cooling action by the blower fan may be practically useful in the state where the temperature of the high-voltage transformer is increased. Only when the set time is reached, a method of driving the fan motor 26 may be introduced. This will be described with reference to FIG. 3.

Referring to FIG. 3, a cooking condition set by a user is set through the input unit 56 (80). Accordingly, the controller 54 determines whether an input command by the user starts cooking (82). When the input command for the cooking start is input, the controller 54 controls the relay driver 52 to turn on the inrush relay 32 and the power relay 36 in order to drive the magnetron 50 and the motor. The relay 28 is turned on to drive the fan motor 26. Accordingly, the cooking is made and the blower fan is operated by the fan motor (84). At this time, the controller 54 counts the driving time of the magnetron using an internal counter (86), and then the controller 54 determines whether a cooking stop command is input through the input unit 56 (88), and the determination result. When the cooking stop command is input, the controller 54 determines whether the drive time of the counted magnetron reaches the second preset time. The second set time is set to approximately 10 minutes (90). As a result of the determination, when the counted time reaches the second set time, the controller 54 controls the relay driver 52 to turn off the power relay 36 and turn on the motor relay 28. Accordingly, the driving of the magnetron is stopped, but the cooling action by the blowing fan is continued by the driving of the fan motor 26 (92). At this time, the controller 54 counts the driving time of the blowing fan using the internal counter (94), and determines whether the counted time reaches the first predetermined time. Here, the first preset time is approximately 1 minute (96).

As a result of the determination, if the counted time does not reach the first set time, the operation returns to operation 92 to continue to operate the blower fan.

As a result of the determination, when the counted time reaches the first preset time, the operation returns to operation 88.

When the cooking stop command is not input as a result of the determination in operation 88 or when the driving time of the counted magnetron does not reach the second preset time as a result of the determination in operation 90, the controller 54 corresponds to the end of cooking according to the passage of the cooking time. If it does not correspond to the end of cooking, the process returns to operation 84 to continue cooking.

As a result of the determination, when the cooking ends, the controller 54 controls the relay driver 52 to turn off the power relay 36 and to turn off the motor relay 28. Accordingly, the driving of the magnetron is stopped, the cooking operation is finished, and the blowing fan is stopped (91).

As described in detail above, the present invention can achieve miniaturization of an electric component (high voltage transformer) by continuing to cool the electric component (high voltage transformer) during cooking as well as when cooking is stopped.

Claims (8)

Electrical parts provided in the machine room to generate a high frequency, a blowing fan for blowing outside air to cool the electrical parts, a fan driver for driving the blowing fan, and if the cooking is stopped by controlling the fan driver Microwave oven comprising a controller for driving a blowing fan. The fan driving unit of claim 1, wherein the fan driving unit includes a fan motor and a motor relay, wherein the motor relay supplies driving power to the fan motor under control of the controller, and the fan motor drives the blower fan when power is supplied. Microwave oven characterized in that. The microwave oven according to claim 1, wherein the controller drives the blower fan for a set time. The microwave oven of claim 1, wherein the electrical component includes a high voltage transformer and a magnetron, and the high voltage transformer boosts an input voltage to apply a high voltage to the magnetron. It is determined whether a cooking stop command is input during cooking using an electrical component such as a high voltage transformer and a magnetron. When the cooking stop command is input, the cooking is stopped by cutting off the driving power supplied to the electrical part. Control method of a microwave oven, characterized in that for performing cooling. 6. The method of claim 5, wherein the cooling of the electric component drives a blower fan to blow external air. 7. The control method according to claim 6, wherein the blowing fan is stopped when the driving time of the blowing fan is counted and the counted time reaches the first set time. 7. The control method according to claim 6, wherein the blowing fan is driven when the driving time of the magnetron driving for cooking is counted and the counted time reaches the second set time.