KR100420532B1 - Method for preventing a microwave range from operating in idling condition - Google Patents

Abstract

The present invention relates to a control method for preventing the microwave from operating in the no-load state by detecting whether the inside of the cooking chamber is in a no-load state by the amount of temperature change detected in the cooking chamber.

The present invention is a step of sensing the temperature change by the temperature sensor inside the cooking chamber when the microwave oven is driven; Calculating a voltage change value according to the temperature change amount by the microcomputer; Determining whether the voltage change value calculated by the microcomputer is within a range of a voltage change value of a preset no-load state at predetermined time intervals; And stopping the driving of the microwave oven by the microcomputer if the calculated voltage change value is within a range of the voltage change value in the no-load state.

Description

Method for preventing a microwave range from operating in idling condition}

The present invention relates to a method for controlling the operation of a microwave, and more particularly, a control method for preventing the microwave from operating in a no-load state by detecting whether the inside of the cooking room is no-load by the amount of temperature change detected in the cooking chamber. It is about.

In general, a microwave oven vibrates water molecules contained in food by applying high voltage electricity to the high frequency oscillation tube, the netron, and rapidly moves the food outside and inside simultaneously by frictional heat. It is an electronic product which heats up easily.

The microwave oven is composed of a cooking chamber which is a cooking space inside the main body of the microwave oven and an electric equipment chamber having various driving devices for driving the microwave oven.

The inside of the cooking chamber is provided with a rotary tray for rotating the food to uniformly cook the whole, the lower portion of the rotary tray is equipped with a drive motor for rotating the rotary tray.

In the electrical compartment, high-voltage transformers, high-voltage capacitors, high-voltage diodes, magnetrons, and cooling fans for cooling each of these driving devices are installed as components necessary for oscillating high frequency, a cooking heating source of food. The high voltage transformer applies the high voltage required to the magnetron to generate a high frequency.

On the other hand, when the microwave oven is operated in the absence of food in the cooking chamber, that is, in the no-load state, since the high frequency oscillated from the magnetron has no object to be irradiated, the high frequency is reflected back to the magnetron and returned. . Accordingly, it is possible to cause fatal damage to various drive devices such as electrical components in the cooking chamber and magnetrons in the electrical compartment.

Therefore, in order to prevent the microwave from operating in such a no-load state, as shown in FIG. 1, a thermostat 3 is installed at one side of the magnetron 2 disposed outside the cooking chamber 1. do.

The thermostat (3) is a temperature control device for maintaining a constant temperature, and when the temperature rises up to a certain temperature by using an amount changed by the temperature rise, the temperature rise is stopped by this change amount. At this time, a mechanism such as expansion of water temperature or curvature of bimetal is used.

When there is no food in the cooking chamber 1, that is, no load state, since the high frequency oscillated from the magnetron 2 has no object to irradiate, this high frequency wave reflects back to the magnetron 2 and returns. Accordingly, the reflected high frequency is converted into heat, and the changed heat causes the thermostat 3 attached on the outer surface of the magnetron to operate to stop the no-load operation state of the microwave oven.

However, in the conventional microwave oven, the high frequency oscillated from the magnetron is reflected back to the magnetron, the reflected high frequency is converted into heat, and the thermostat is operated by the converted heat. Therefore, such a complicated and slow operation has a problem that it is very difficult to detect the no-load state of the microwave oven and to prevent the microwave from operating in the no-load state.

In addition, since the temperature inside the cooking chamber is sensed by a thermostat mounted outside the cooking chamber, it is not able to efficiently detect the no-load operating state, and in the case of a product that cannot easily reflect high frequency depending on the type of microwave oven, the no-load operation There was a disadvantage that the detection of the condition was very difficult.

The present invention has been made to solve the above problems, by detecting and preventing the no-load operation state of the microwave oven by the amount of temperature change detected inside the cooking chamber, it is possible to achieve a simple and fast detection and prevention of no-load operation. It is an object of the present invention to provide a method for preventing the no-load operation of a microwave oven.

1 is a schematic view showing a conventional microwave oven.

2 is a conceptual diagram of an apparatus for implementing the method of preventing the no-load operation of the microwave oven of the present invention.

3 is a flowchart illustrating a method of preventing a no-load operation of a microwave oven according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: cooking chamber 20: temperature sensor

30: microcomputer PCB: printed circuit board

The present invention for achieving the above object, the microwave oven is driven, the step of sensing the temperature change amount by a temperature sensor inside the cooking chamber; Calculating a voltage change value according to the temperature change amount by the microcomputer; Determining whether the voltage change value calculated by the microcomputer is within a range of a voltage change value of a preset no-load state at predetermined time intervals; And stopping the driving of the microwave oven by the microcomputer if the calculated voltage change value is within a range of the voltage change value in the no-load state.

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

2 is a conceptual diagram of an apparatus for executing a method for preventing the no-load operation of the microwave oven of the present invention, and FIG. 3 is a flowchart illustrating the method for preventing the microwave no-load operation of the present invention.

First, as shown in FIG. 2, the microwave no-load operation preventing device according to the present invention further includes a temperature sensor 20 at a predetermined point inside the cooking chamber 10 in a general microwave oven, and the temperature sensor 20. ) Is electrically connected to the microcomputer 30 on the printed circuit board (PCB).

On the other hand, the above-described temperature sensor 20 may use a semiconductor device with a large change in electrical resistance with temperature, such as a thermistor (thermistor), such a negative resistance characteristics of the thermistor, the resistance value is reversed decreases as the temperature increases There is also a positive resistance thermistor in which the resistance increases with the recent increase in temperature. However, in one embodiment of the present invention, a negative resistance thermistor is used.

When the temperature change in the cooking chamber 10 is detected by the temperature sensor 20, the microcomputer 30 connected to the temperature sensor 20 calculates a change in voltage according to the temperature change. Accordingly, by comparing the voltage change value of the no-load state preset by the amount of change of the voltage detected by the microcomputer 30 to detect whether the microwave oven operates in the no-load state.

Hereinafter, a method of preventing the no-load operation of the microwave oven according to the present invention will be described in detail.

As shown in Figure 3, first, it is determined whether the microwave is on (S1).

When the microwave oven is driven, the temperature sensor 20 detects a temperature change in the cooking chamber at a predetermined time interval ΔT (S2), and a difference in voltage input to the microcomputer 30 by the detected temperature change amount. The microcomputer 30 calculates a change value of the voltage according to the temperature change amount detected by the temperature sensor (S3).

Next, it is judged whether or not the above-described voltage change value is within the range (ΔV) of the voltage change value at no load state at the set predetermined time interval (ΔT), and the voltage change value is within the range of the voltage change value at no load state If (ΔV) is inside (S4), the microwave is stopped (S5).

Here, the range (ΔV) of the voltage change value in the no-load state described above may be set as shown in Table 1 below, wherein the predetermined time interval ΔT for calculating the temperature and voltage change values is 30 seconds apart. Is set. In addition, it is obvious that the range (ΔV) and the detection time of the voltage change value in the no-load state may be variously changed according to the product specifications of the microwave oven and the surrounding environment.

Range of voltage change in no-load state (ΔV) Detection time (△ T) Voltage value Voltage value △ V1 30 seconds 0.02V 0.10 V △ V2 60 seconds 0.07V 0.20V △ V3 90 sec 0.14 V 0.30V △ V4 120 seconds 0.20V 0.40V △ V5 150 sec 0.30V 0.50V △ V6 180 seconds 0.40V 0.60V

On the other hand, if the voltage change value is outside the range (ΔV) of the voltage change value in the no-load state, it returns to the step S2 and continuously detects whether it is in the no-load state.

The present invention as described above has a very excellent effect that can achieve a simple and fast detection and prevention of no-load operation by detecting and preventing the no-load operation state of the microwave oven by the amount of temperature change detected in the cooking chamber.

In the above, the present invention has been illustrated and described with respect to certain preferred embodiments. However, the present invention is not limited only to the above-described embodiments, and those skilled in the art to which the present invention pertains may vary without departing from the spirit of the technical idea of the present invention described in the claims below. It may be changed.

Claims (1)

Detecting a temperature change amount by a temperature sensor inside the cooking chamber when the microwave oven is driven; Calculating, by the microcomputer, a voltage change value according to the temperature change amount; Determining whether the voltage change value calculated by the microcomputer is within a range of a voltage change value of a preset no-load state at a predetermined time interval; And And stopping the driving of the microwave oven by a microcomputer if the calculated voltage change value is within a range of the voltage change value of the no-load state.