KR20000031336A - Automatic deciding apparatus for cooking load of microwave oven - Google Patents

Abstract

PURPOSE: An automatic deciding apparatus of a cooking load is provided to automatically cook a cooking material by proper cooking time and cooking output after deciding the cooking load injected into a cooking chamber by detecting output voltage. CONSTITUTION: A key input unit(150) feeds the command of a user to a control unit(140) so the control as to control the action of a drive unit(110). A display unit(160) indicates the working state of a microwave oven through the control unit. A microwave oscillating unit(120) is driven by the voltage fed from a high voltage transformer(HVT). A voltage detecting unit(130) detects the output voltage of the microwave oscillating unit while the control unit decides the cooking load injected into a cooking chamber by employing the output voltage. Also, the drive unit drives the microwave oven with proper cooking time and cooking output depending on the cooking load. A filter matching unit(100) feeds alternating currents(AC) to the drive unit and prevents high frequency from feeding back to an input line.

Description

Automatic Cooking Load Determination Device of Microwave Oven

The present invention relates to a microwave oven, and more particularly, to a cooking load automatic determination device of a microwave oven for automatically determining a cooking load put into a cooking chamber.

In general, a microwave oven is a device for heating / cooking food using microwaves. To this end, a high voltage transformer typically boosts an AC power supply of 120/230 V to a high voltage, and the magnetron is driven at this high voltage to generate microwaves of approximately 2450 MHz. This microwave vibrates the water molecules contained in the food, and the food is heated / cooked by the heat generated at this time.

1 is a partial cutaway perspective view showing a typical microwave oven. In Fig. 1, reference numeral 1 denotes a main body, 2 a cooking chamber, 3 a device chamber, 4 a door, 5 a rotary plate, and 6 a cover. The main body 1 is divided into left and right spaces, and on one side, a cooking chamber 2 having an open front is provided, and on the other side, an apparatus chamber 3 in which various electric appliances are installed is provided. In addition, the cover 6 is formed on the upper and side surfaces of the main body 1 to form an external shape of the microwave oven. The door 4 is rotatably fixed to one side of the main body 1 so as to open and close the front of the cooking chamber 2. Rotating plate 5 is installed on the bottom surface of the cooking chamber 2, the food to be cooked is placed on the upper surface. The rotary plate 5 is rotated by a drive motor (not shown) provided on its bottom surface. In addition, reference numeral 7 denotes a front panel, 8 an air guide, 9 a cooling fan, HVT is a high voltage transformer, HVC is a high voltage capacitor, HVD is a high voltage diode, and MGT is a magnetron. These are installed in the apparatus chamber 3. The high voltage transformer (HVT) boosts the AC / AC of 120 / 230V to a voltage of approximately 2000V, which is converted into a high voltage of approximately 4000V through the high voltage capacitor (HVC) and the high voltage diode (HVD). Magnetrons (MGTs) are driven at this high voltage to generate microwaves of approximately 2450 MHz. The cooling fan 9 blows air to cool the electrical components inside the apparatus chamber 3, in particular, the magnetron (MGT), the high voltage transformer (HVT), and the like, which generate high heat. The air guide 8 is installed near the magnetron (MGT) to guide the heated air in the cooling process of the magnetron (MGT) to the cooking chamber (2). The front panel 7 is installed on the front of the apparatus room 3 to input the operation state of the user and display the operation state of the microwave oven.

FIG. 2 is a control block diagram schematically illustrating FIG. 1. In FIG. 2, reference numeral 10 is a filter matching unit, 20 is a driving unit, 30 is a microwave oscillating unit, 40 is a control unit, 50 is a key input unit, and 60 is a display unit. The key input unit 50 receives a user's operation command and applies it to the control unit 40, and the control unit 40 controls the operation of the driving unit 20. The display unit 60 displays the operation state of the microwave oven by the control unit 40. The key input unit 50 and the display unit 60 are preferably formed on the front panel 7 shown in FIG. The driving unit 20 operates various microwave driving loads such as the rotating plate 5, the cooling fan 9, and a lamp (not shown) described with reference to FIG. 1. Microwave oscillation unit 30 is composed of a high-voltage capacitor (HVC), a high-voltage diode (HVD) and a magnetron (MGT) is driven by the voltage supplied from the high-voltage transformer (HVT) and its action is as described above in FIG. The filter matching unit 10 receives the AC power source AC and applies it to the driving unit 20 to prevent the high frequency generated from the microwave oscillation unit 30 from being fed back to the input line.

Referring to the operation of the conventional microwave oven configured as described above in detail.

First, the user places the food on the upper end of the rotating dish 5 in the state in which the cooking chamber 2 is opened by opening the door 4 on one side of the main body 1. Then, the user closes the door 4 and operates the key input unit 50 formed on the front panel 7 to set a cooking time or cooking output according to the amount of food, and then operate the microwave oven. When the operation command of the microwave is input from the key input unit 50 as described above, the control unit 40 detects this and operates the driving unit 20. The driving unit 20 operates various microwave driving loads such as the rotating plate 5, the cooling fan 9, and a lamp (not shown), and applies AC power AC to the high voltage transformer HVT. AC power applied to the high voltage transformer HVT is converted into high voltage through the high voltage capacitor HVC and the high voltage diode HVD and then supplied to the magnetron MGT. Magnetron MTG is driven at the high voltage to generate microwaves. The microwave thus generated is emitted into the cooking chamber 2 to heat / cook the food. In addition, the inside of the cooking chamber 2 is rotated to rotate the rotating dish 5 is settled in the food to microwave the food evenly in the cooking chamber, in the apparatus chamber 3, the cooling fan 9 blows air to the inside Cool the electronics.

In addition, the food inside the cooking chamber 2 is appropriately heated / cooked through the above operation according to a cooking time or cooking output condition preset by the user. Here, since the microwave itself cannot determine the amount, type, shape, or volume of food, the operating conditions are usually set by the user's judgment and manipulation. However, if the cooking time is too short or the output is weak compared to the amount of food, the food will be unripe. On the contrary, if the cooking time is too long or the cooking power is strong compared to the amount of food, the food will burn. . Therefore, in order to cook the food accurately to the extent desired by the user, it is very important to accurately set the cooking time or the cooking power according to various cooking load conditions such as the quantity, type, shape, or volume of the food. . In a conventional microwave oven, a cooking load of a basic food is set by a product designer and exists as each function key in the key input unit 50 of the front panel 7. Therefore, a user can select this function key to immediately perform cooking. In the absence of a function key, the user sets the cooking time or cooking output directly.

However, such a conventional microwave oven, the user directly checks / determined the degree of various cooking loads such as the quantity, type, shape, or volume of the food put into the cooking chamber, and finds and inputs the corresponding function key. Or if there is no function key, the conditions such as cooking time or cooking power should be set intuitively or empirically. Therefore, if the operation and judgment is very inconvenient and complicated, and the user cannot set the correct cooking time according to the amount of food according to the user, proper cooking may not be performed. If manipulated, there is a problem in that it is not possible to obtain a cooked food that is cooked to a desired degree.

In addition, conventionally, there is an example in which a cooking load can be determined using a gas sensor or a weight sensor, but since these are very expensive parts, the installation and manufacturing process is complicated, thereby increasing the production cost of the product and improving workability. There are also other problems that degrade.

Therefore, the present invention has been made in order to solve the above-mentioned conventional problems, the object of the present invention is to detect the output voltage and determine the cooking load put into the cooking chamber, according to the appropriate cooking time or cooking output It is to provide a cooking load automatic determination device of the microwave oven to be automatically cooked.

Another object of the present invention is to provide a cooking load automatic determination device for a microwave oven, in which a production cost is reduced by using a low cost component, and a production process is simplified to improve product productivity.

1 is a partial cutaway perspective view showing a typical microwave oven,

2 is a control block diagram schematically showing FIG.

3 is a control block diagram showing a preferred embodiment of the automatic cooking load determination device of the microwave oven according to the present invention;

4 is a detailed circuit diagram illustrating a main part of FIG. 3;

5 is a graph showing the amount of change per hour of the magnetron output voltage according to the cooking load.

Explanation of symbols on the main parts of the drawings

110: driver 130: voltage detector

140: control unit HVT: high voltage transformer

MGT: Magnetron R10, R11: Resistance

Vap: Output Voltage Vbs: Bias Voltage

The automatic cooking load determination device of the microwave oven according to the present invention for realizing this, the voltage detection unit for detecting the output voltage and the control unit for determining the cooking load input into the cooking chamber using the output voltage detected by the voltage detection unit. Include. Preferably, the voltage detector detects an output voltage between both ends of the magnetron. The voltage detector includes at least one resistor connected in parallel to the magnetron. The voltage detector applies a bias voltage to one end of the resistor, and the controller receives the output voltage detected by the voltage detector for a predetermined time to determine the cooking load according to the change amount of the output voltage. The apparatus may further include a driving unit for driving the microwave oven according to the cooking load determined by the controller.

Therefore, the user does not need to determine the cooking load to be put into the cooking chamber or set the cooking time or cooking output accordingly, and detects the output voltage in the microwave itself to determine the cooking load put into the cooking chamber. Since the food is automatically cooked at a proper cooking time or cooking power, food can be cooked more conveniently and accurately. In addition, using low cost components can reduce production costs and simplify the manufacturing process, thereby improving productivity.

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

3 is a control block diagram showing a preferred embodiment of the automatic cooking load determination device of the microwave oven according to the present invention. Here, reference numeral 100 is a filter matching unit, 110 is a driving unit, 120 is a microwave oscillation unit, 130 is a voltage detector, 140 is a controller, 150 is a key input unit, and 160 is a display unit. The key input unit 150 receives a user's operation command and applies it to the controller 140, and the controller 140 controls the operation of the driver 110. The display unit 160 displays the operation state of the microwave oven by the controller 140. The microwave oscillator 120 is driven by the voltage supplied from the high voltage transformer (HVT). The voltage detector 130 detects the output voltage Vap of the microwave oscillator 120, and the controller 140 uses the output voltage Vap detected by the voltage detector 130 to adjust the cooking load input into the cooking chamber. To judge. To this end, the controller 140 may receive the output voltage Vap detected by the voltage detector 130 for a predetermined time and determine the cooking load according to the change amount of the output voltage Vap. In addition, the driving unit 110 drives the microwave oven with an appropriate cooking time or cooking output according to the cooking load determined by the control unit 140. The filter matching unit 100 receives the AC power source AC and applies it to the driving unit 110, and prevents the high frequency generated from the microwave oscillation unit 120 from being fed back to the input line.

4 is a detailed circuit diagram illustrating the main part of FIG. 3. Here, the microwave oscillator 120 is composed of a high voltage capacitor (HVC), a high voltage diode (HVD) and a magnetron (MGT) to drive at a voltage supplied from the high voltage transformer (HVT). The voltage detector 130 may detect the output voltage Vap between both ends of the magnetron MTG. To this end, the voltage detection unit 130 includes at least one resistor (R10) (R11) connected in parallel to the magnetron (MGT). In addition, the voltage detector 130 applies a bias voltage Vbs to one end of the resistor R11. The bias voltage Vbs is preferably supplied with a positive voltage (+). Unexplained ZD is a zener diode. The driver 110 includes a switching transistor Q1 turned on and off by the controller 140 and a relay RY1 operated according to the on / off state of the transistor Q1. The relay RY1 is composed of a relay coil L1 through which current is conducted according to an on / off state of the transistor Q1, and a relay contact RS1 on / off by the relay coil L1. Reference numeral D1 denotes a diode for preventing reverse voltage.

5 is a graph showing the amount of change in the magnetron output voltage according to the cooking load per hour, in which the output voltage Vap of the microwave oscillator 120 changes according to the cooking loads A, B, and C input to the cooking chamber. The figure which shows the result of having measured the quantity for the predetermined time.

According to the preferred embodiment of the present invention configured as described above, the user inputs food into the cooking chamber without setting cooking time or cooking output according to the amount of food to be cooked, and then directly manipulates the key input unit 150. Start the microwave. When the operation command of the microwave is input from the key input unit 150 as described above, the control unit 140 detects this and operates the driving unit 110. The driving unit 110 operates the driving load of the microwave oven and applies an AC power source AC to the high voltage transformer HVT. In more detail, the control unit 140 turns on the switching transistor Q1 of the driving unit 110, so that a current is conducted to the relay coil L1. The relay coil L1 turns on the relay contact RS1 so that the AC power source AC is applied to the high voltage transformer HVT. Subsequently, the AC power source AC applied to the high voltage transformer HVT is converted into high voltage through the high voltage capacitor HVC and the high voltage diode HVD and then supplied to the magnetron MGT. Magnetron MTG is driven at the high voltage to generate microwaves.

In this state, the voltage detector 130 detects the output voltage Vap between both ends of the magnetron MGT using the resistors R10 and R11 connected in parallel to the magnetron MGT. Since the output voltage Vap is usually detected as a negative voltage (−), a bias voltage Vbs is applied to one end of the resistor R11 to convert the output voltage Vap to a positive voltage (+). The operation of the controller 140 is facilitated. The controller 140 may receive the output voltage Vap detected by the voltage detector 130 for a predetermined time and determine the cooking load according to the change amount of the output voltage Vap. That is, as shown in Figure 5, the cooking load (A) (B) (C) put into the cooking chamber by analyzing the result of measuring the amount of change in the output voltage (Vap) of the microwave oscillation unit 120 for a predetermined time Will be judged. In addition, the controller 140 may operate / control the driving unit 110 according to the cooking load determined above to drive the microwave oven at an appropriate cooking time or cooking output, thereby making it possible to cook food more conveniently and accurately.

As described above, according to the automatic cooking load determination apparatus of the microwave oven according to the present invention, the user does not have to determine the cooking load to be put into the cooking chamber or set the cooking time or cooking output accordingly, and the microwave itself. Determining the output load in the cooking chamber to determine the cooking load put into the cooking chamber, thereby automatically cooking the food at a suitable cooking time or cooking output, there is an effect that the food can be cooked more conveniently and accurately.

In addition, it is possible to detect the cooking load using low-cost parts such as resistors without using expensive gas sensors or weight sensors to detect cooking loads put inside the cooking chamber, thereby reducing production costs and improving the manufacturing process. There are other effects that can be simplified to improve productivity.

In addition, when designing a microwave oven, it is not necessary to set the cooking load of basic foods in advance, and there is no need to make function keys according to it, and there is another effect that can further improve the productivity due to the reduction of parts and the simplicity of production. have.

While the invention has been shown and described with respect to certain preferred embodiments, the invention is not limited to the embodiments described above, but in the field to which the invention pertains without departing from the spirit of the invention as claimed in the claims. Various modifications are possible by those skilled in the art, and such changes are within the scope of the claims as set forth.

Claims (6)

A voltage detector detecting an output voltage; And And a control unit for determining a cooking load input into the cooking chamber by using the output voltage detected by the voltage detecting unit. The method of claim 1, wherein the voltage detector, A cooking load automatic judgment device for a microwave oven, characterized in that it detects an output voltage between both ends of a magnetron. The method of claim 2, wherein the voltage detector, The cooking load automatic determination device of the microwave oven, characterized in that it comprises at least one resistor connected in parallel to the magnetron. The method of claim 3, wherein the voltage detector, Cooking load automatic determination device of a microwave oven, characterized in that to apply a bias voltage to one end of the resistance. The method according to any one of claims 1 to 4, wherein the control unit, And an output voltage detected by the voltage detector for a predetermined time so as to determine a cooking load according to a change amount of the output voltage. The apparatus of claim 5, further comprising a driving unit for driving the microwave oven according to the cooking load determined by the controller.