KR100225625B1 - Controlling apparatus of heating temperature for microwave oven - Google Patents

Abstract

The present invention senses the temperature of the food cooked in the microwave oven to determine the current state of cooking of the food based on the detected temperature and cooking time and then adjust the heating temperature food heating temperature of the microwave oven to improve cooking efficiency A control apparatus, comprising: a cooking chamber having a predetermined space for cooking food, a magnetron for generating a high frequency to cook the food, and a microwave oven having a rotating plate for rotating the food so that the high frequency is uniformly incident on the food. A temperature detecting means for detecting a present temperature of the cooked food, a second control means for comparing the food temperature value detected by the temperature detecting means with a reference value and generating an output signal as a result of the comparison; Song for generating a remote signal corresponding to the food temperature value in accordance with the output signal of the second control means Means, a receiving means for receiving the food temperature value transmitted from the transmitting means, and a food temperature value inputted through the receiving means to determine the current food cooking state, and according to the determination result, the heating temperature of the food Characterized in that the first control means for controlling the.

Description

Food heating temperature control device of microwave oven

1 is a schematic front sectional view of a conventional microwave oven.

2 is a schematic front sectional view of the microwave oven of the present invention.

Figure 3 is a schematic layout of the second DC power supply means, the transmission means of the present invention.

4 is a block diagram of a food heating temperature control apparatus of the present invention.

5 is a detailed circuit diagram of the temperature detecting means, the transmitting means and the receiving means of FIG.

6 is a voltage waveform diagram of a transmitting means and a receiving means of FIG.

7 is a graph of the relationship between the temperature of food and the waveform period.

8 is a graph of the relationship between food temperature and cooking time.

9 is an operation circuit diagram of a second DC power supply driving means of the present invention.

* Explanation of symbols for main parts of the drawings

20, 25: DC power supply means 40, 41: control means

70: temperature detecting means 80: transmitting means

90: receiving means

The present invention can improve the cooking efficiency by adjusting the heating temperature of the food after detecting the temperature of the food to be cooked in the microwave, determining the current cooking state based on the detected temperature and cooking time. The present invention relates to a food heating temperature control device for a microwave oven.

As a specific conventional example, as shown in FIG. 1, the cooking chamber 3 is formed at a predetermined portion inside the main body 1 to prevent the heat source applied to the food F from flowing out. At the lower right end of 3), a high voltage transformer 5 generating high pressure when the microwave oven is operated is mounted.

In addition, a magnetron 7 that generates a high frequency by receiving a high pressure from the high voltage transformer 5 is mounted on an upper portion of the high voltage transformer 5, and the magnetron 7 is located at a lower left end of the magnetron 7. A waveguide 9 is formed to guide the high frequency generated in the cooking chamber 3.

In addition, the cooking dish 3 has a rotating dish 11 mounted therein and rotated during the operation of the microwave oven so that the rotating dish 11 placed thereon evenly cooks the food F. At the lower end of the rotary plate 11, a rotary plate roller 13 supporting the rotary plate 11 is mounted.

At the lower end of the rotary plate roller 13, the rotary plate (when the microwave oven is driven)

11) is equipped with a drive motor 15 for generating a driving force to rotate.

In the conventional microwave oven configured as described above, when the food (sea animal) to be cooked is placed on the rotary dish 11 in the cooking chamber 3 formed at a predetermined portion of the main body 1, the magnetron is selected. The high frequency generated in (7) is guided through the waveguide (9) and hydraulically distributed into the cooking chamber (3).

The high frequency introduced and dispersed into the cooking chamber 3 is reflected by the metal wall, which is a structure of the cooking chamber 3, and is applied to the food F from various directions or directly to the food F, while being applied to the food dish F. It starts to heat uniformly the food F rotated by it.

In this state, the temperature of the food to be cooked is detected and based on the detected result, the control means (not shown) adjusts the heating temperature in the cooking chamber 3. A conventional microwave oven is a method for detecting food temperature. There are two ways to do this:

One is to use a non-contact infrared sensor. That is, in the infrared sensor method, when the infrared sensor is mounted at a predetermined place inside the cooking chamber of the microwave oven and emits infrared rays toward the food under the control of the control means, the control means receives the reflected signal and displays the current of the food in the control means based on the received value. It is to detect the temperature. However, such an infrared sensor method has a disadvantage that the cost is rather expensive.

Another method is to use a probe, which is a contact method. That is, the probe method is a method of adjusting a heating temperature based on a temperature detected by contacting a probe directly with food.

However, such a probe method is not only more likely to detect the temperature of the food than the food, but also inconvenient to use, so the detection result is also inaccurate.

Accordingly, an object of the present invention is to improve the disadvantages as described above, an object of the present invention is to detect the temperature of food using a temperature detecting element mounted on the bottom of the rotating plate, and based on the detection result of the heating temperature of the food The present invention provides an adjustable food heating temperature control device of a microwave oven.

In order to achieve the above object, the present invention provides a food compartment such that a cooking chamber having a predetermined space for placing food thereon, a magnetron generating high frequency to cook the food, and a high frequency generated by the magnetron are uniformly delivered to the food. In a microwave oven having a rotating dish for rotating, a temperature detecting means for detecting a present temperature of the cooked food, and a food temperature value detected by the temperature detecting means are compared with a reference value to output an output signal as a comparison result. A second control means for generating, a transmitting means for generating a remote signal corresponding to a food temperature value according to the output signal of the second control means, a receiving means for receiving a food temperature value transmitted from the transmitting means, and After analyzing the food temperature value input through the receiving means to determine the current food cooking state, And the second being configured as a first control means for controlling the heating temperature of the food in accordance with the end result.

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

The same reference numerals are given to the same constituent parts as in FIG. 1, and redundant descriptions are omitted for convenience.

In FIG. 2 and FIG. 3, the temperature detecting means 70 is attached to the lower side of the rotary dish 11 so as to detect the temperature of the food F which is placed and cooked on the rotary dish 11. The temperature detecting means 70 uses a thermistor which is a conventional temperature sensor. In other words, since the thermistor has a characteristic that the resistance value changes with temperature, the temperature of the food to change is detected using this principle.

In addition, at a constant outside of the cooking chamber 3, a transmitting means 80 for generating a predetermined signal is arranged according to a result of comparison between the temperature detected by the temperature detecting means 70 and the reference value of the second control means described later. It is. The output signal of the transmitting means 80 is sent to the first control means through the receiving means 90 to be described later to control the heating temperature based on the temperature of the current food.

In addition, a second DC power supply unit 25 for supplying a DC voltage necessary for driving the temperature detecting means 70, the transmitting means 80, and the second control means is provided at a predetermined outer lower portion of the cooking chamber 3. This second DC power supply means 25 is a battery.

4 to 8, the first DC power supply means 20 converts a commercial AC voltage supplied from an AC power supply terminal (not shown) into a predetermined DC voltage required for driving the microwave oven.

The second DC power supply means 25 is composed of a battery by supplying a DC voltage necessary for driving the temperature detecting means 70, the transmitting means 80, and the second control means 41.

The key input unit 30 is provided with a plurality of function keys on the control panel to input a cooking function (cooking time, cooking menu, output of the microwave, start / stop of cooking operation, etc.) desired by the user.

In addition, the first control unit 40 receives the DC voltage output from the first DC power supply unit 20 to initialize the microwave oven, and at the same time, to the key signal input by the key input unit 30. Therefore, the microcomputer controls the overall cooking operation of the microwave oven.

The first control means 40 also stores a program for adjusting the oscillation output of the magnetron 7 to control the heating temperature based on the food temperature detected by the temperature detection means 70.

In addition, the first control means 40 is controlled so that the intensity of the high frequency output oscillated from the magnetron 7 for the first predetermined time after the start of the microwave drive is different from the high frequency output oscillated from the magnetron 7 for a predetermined time thereafter. The control program is stored.

That is, as shown in FIG. 7 and FIG. 8, during the first predetermined time, the oscillation output of the magnetron 7 is increased so that the temperature of the food F reaches a certain temperature (a ° C) relatively quickly. During a certain time, the temperature of the food F rises relatively slowly to reach the temperature of the cooking completion point of the food F.

In addition, the magnetron driving means 50 receives the control signal output from the first control means 40 according to the key signal input by the key input means 30 to supply or cut off the driving power of the magnetron 7. It is.

The display means 60 displays the cooking time or cooking menu input by the user by the key input means 30 under the control of the first control means 40.

As shown in FIG. 5, the second control means 41 compares the temperature of the food and drink detected by the temperature detection means 70 with a reference value and generates the comparison result as an output signal. The non-inverting terminal to which the voltage value Va set according to the food temperature detected by the detecting means is input, and the reference voltage value Vr compared with the voltage value Va corresponding to the food temperature input to the non-inverting terminal. A comparator composed of the set inverting terminals, a diode D1 for converting the voltage value Va into a square wave voltage having a constant value, and the reference voltage value (

It is comprised by the capacitor C which removes the ripple of Vr.

The transmitting means 80 remotely transmits the temperature value of the food to the receiving means 90, as shown in FIG. 5, by the output signal of the comparator 42 of the second control means 42. The transistor 81 is turned on or off, and the light emitting diode 82 emits light as the transistor 81 is turned on.

The receiving means 90 receives the food temperature signal input from the transmitting means 80 and inputs it to the first control means 40. The receiving means 90 turns on or off by the signal output from the transmitting means 80. The phototransistor 91 is comprised.

On the other hand, in FIG. 4, the lifespan of the second DC power supply means 25 that applies a voltage required for driving the second control means 41, the temperature detecting means 70, and the transmitting means 80 is extended. In order to extend, the circuit shown in FIG. 9 is used, which will be described in detail as follows.

Even when the microwave oven is not operated, the battery of the second DC power supply means 25 has a temperature detecting means 70.

By applying power to the second control means 41 and the transmission means 80, a comparison operation according to temperature detection and a signal transmission / reception operation generated according to the comparison result are performed. As shown in FIG. 9 in order to prevent life shortening, the battery is operated only by the control signal of the first control means 40. That is, for example, when the user operates the operation start button through the key input means 30, the first control means 40 that recognizes the high level signal outputs the high level signal to the second DC power supply driving means 26 so that the transistor ( TR1 is turned on, and the phototransistor PH1 receiving this light is also turned on by the light emitting diode LED1 connected to the collector of the transistor TR1 being emitted by the voltage Vcc applied through the resistor R11. do. Accordingly, the transistor TR2 connected to the base of the phototransistor PH1 via the resistor R13 is turned on to drive the battery having the positive terminal connected to the emitter of the transistor TR2. Will be.

The operation procedure of the food heating temperature control device of the present invention configured as described above will be described in detail.

First, when the food to be cooked is placed on the rotating plate 11 and the power is applied, the first DC power supply unit 20 converts the commercial AC voltage supplied from the AC power source into a predetermined DC voltage required for driving the microwave. Supply to the key input means 30, the first control means 40, the magnetron driving means 50, the display means 60 and the receiving means (90). As a result, each of the components becomes an operating state. At the same time, as described above, the first control means 40 sends a high level signal to the second DC power drive means 26 to drive the battery, and the battery power is supplied to the second control means 41 and the temperature. It is applied to the detection means 70 and the transmission means 80 to cause each component to be in an operating state.

Then, when the user presses the stop button of the key input means 30, the control means 40 outputs a control signal for driving the magnetron 7 to the magnetron driving means 50. Accordingly, the magnetron driving means 50 oscillates the magnetron 7 by the control signal of the first control means 40 so as to generate a high frequency, and the generated high frequency is generated in the cooking chamber 3 through the waveguide 9. Inflow and dispersion. At this time, the high frequency introduced into and dispersed in the cooking chamber 3 is reflected by the metal wall that is the structure of the cooking chamber 3 and applied to the food F or directly applied to the food F to cook the food F.

That is, the food (F) is uniformly heated while cooking by driving the drive motor 15 fixed to the bottom of the rotary plate 11 by the control of the first control means 40 to rotate the rotary plate 11. do.

At this time, the high frequency output by the oscillation of the magnetron (7) is adjusted to be strong for the first predetermined time, and weak for a certain period thereafter, as shown in FIG. As cooking gradually enters the completion stage, the intensity of occurrence of high frequency is also weakened.

As described above, in the state where the high frequency generated from the magnetron 7 flows into the cooking chamber 3 and heats the food, the temperature detecting means 70 detects the surface temperature of the food.

At this time, as the cooking time of the food elapses, the surface temperature of the food F increases, so that the resistance of the temperature detecting means 70 gradually decreases. That is, the voltage value Va input to the non-inverting terminal + of the comparator 42 of FIG. 5 becomes low, and this voltage value Va is equal to the reference voltage value Vr set in the inverting terminal −. Are compared. As a result of this comparison, when the voltage value Va is greater than the reference voltage value Vr, the output value of the comparator 42 becomes a high level signal, and when the reference voltage value Vr is larger than the input voltage value Va, The output value of the comparator 42 becomes a low level signal. On the other hand, when the output value of the comparator 42 is a high level signal, the transistor 81 is turned on, and thus the light emitting diode 82 is turned on. When the output value of the comparator 42 is a low level signal, the transistor 81 is turned off. Therefore, the light emitting diode 82 is also turned off.

As described above, the light emitting diode 82 transmits a constant frequency signal while repeatedly turning on or off in accordance with the level of the output value that is the result of the comparison of the comparator 42.

This means that the detected value of the temperature detecting means 70 changes, and if the resistance value of the thermistor of the temperature detecting means 70 changes, the voltage value Va of the comparator 42 also changes, and the reference voltage value Since the charge / discharge time of (Vr) also changes, the turn-on or turn-off period (frequency) of the light emitting diode 82 also changes, so that the frequency signal changes according to the temperature of the food.

In this way, the frequency signal that changes in accordance with the temperature change of the food is sent to the receiving means 90 to turn on or off the phototransistor 91. The frequency signal in which the turn-on and turn-off are repeated is converted into a voltage value Vc and input to the first control means 40. Accordingly, the first control means 40 determines the temperature of the food currently being cooked using the reference value stored therein. As a result, when the temperature of the food is lower than the predetermined temperature (a ℃), the food is not yet heated enough.

Maintain strong intensity of high frequency generated from). On the other hand, when the temperature of the food is higher than the predetermined temperature (a ℃), the determination results that the food is sufficiently heated, and sends a control signal for reducing the oscillation output of the magnetron 7 to the magnetron driving means 50. . As a result, the oscillation output of the magnetron 7 is weakened, so that the amount of heat applied to the food is weakened.

In this way, the temperature detection means even while heating the food in a state in which the calorific value is weakened

The detected value of 70 is continuously applied to the transmitting means 80 and compared with the reference voltage value Vr at the comparator 42, and inputted to the receiving means 90 according to the output value of the comparator 42 as a result of the comparison. The frequency signal is different.

The frequency signal thus varied is continuously analyzed by the first control means 40 and compares the magnitude of the food temperature with the constant temperature (b ° C.). As a result of the comparison, when the temperature of the food is lower than the predetermined temperature (b ° C), the food is continuously heated in a state in which the oscillation output of the magnetron 7 is weakened. On the other hand, when the temperature of the food is a predetermined temperature (b ℃) or more as a result of the comparison means that the food has been completed, the first control means 40 is the magnetron driving means 50 for controlling the driving of the magnetron (7) Send a signal. Accordingly, the driving of the magnetron 7 is stopped and the cooking operation is terminated.

As described above, according to the present invention, the heating temperature of the food to be cooked is detected by using the thermistor mounted on the bottom of the rotating plate, and the detected signal is analyzed by the control means received through the transmitting means and the receiving means. By controlling the heating temperature appropriately according to the cooking state of the food has the advantage of improving the cooking efficiency.

Claims (5)

And a cooking chamber having a predetermined space for cooking food, a magnetron for generating a high frequency to cook the food, and a rotating plate for rotating the food so that the high frequency generated by the magnetron is uniformly transmitted to the food. Analyzing the temperature value of the food by the transmitting means for generating a remote signal corresponding to the temperature value of the food detected through the receiving means and the receiving means for receiving the remote signal from the transmitting means and the remote signal received through the receiving means In the microwave food heating temperature control device comprising a first control means for controlling the heating temperature of the food in accordance with the determination result after determining the current food cooking state, the temperature sensing means is a predetermined portion of the rotary dish A thermal resistance variable element attached to the resistor, and a resistance value of the thermal resistance variable element Characterized in that it comprises a temperature detecting means for detecting the current temperature of the food through the second and second control means for generating an output signal as a result of comparing the food temperature value detected by the temperature detecting means with a reference value. Food heating temperature control device of microwave oven. The food heating temperature control apparatus according to claim 1, wherein the temperature detecting means, the second control means, and the transmitting means of the temperature sensing means are driven by receiving a DC voltage from a second DC power supply means. The method of claim 2, wherein the second DC power supply means, by the control of the first control means during operation of the microwave oven directs a DC voltage to the temperature detecting means of the temperature sensing means and the second control means and the transmitting means, etc. Food heating temperature control device of a microwave oven, characterized in that the supply. 4. The light emitting device according to claim 2 or 3, wherein the second DC power supply means emits light when the transistor TR1 is turned on / off in response to a control signal of the first control means, and the transistor TR1 is turned on. A DC voltage applied to a diode DC1, a phototransistor PH1 that is turned on by receiving light of the light emitting diode LED1, and is turned on / off according to an operating state of the phototransistor PH1 and applied from a predetermined DC power source. Food heating temperature control device of a microwave oven, characterized in that consisting of a transistor (TR2) for switching. The non-inverting terminal according to claim 1, wherein the second control means includes a non-inverting terminal to which a voltage value Va set to a predetermined level is input according to the food temperature detected by the temperature detecting means, and a food temperature input to the non-inverting terminal. A comparator comprising an inverting terminal having a reference voltage value Vr to be compared with a voltage value Va corresponding thereto, a diode D1 for converting the voltage value Va into a square wave voltage having a predetermined value, and Food heating temperature control device of a microwave oven, characterized in that consisting of a capacitor (C) for removing the ripple of the reference voltage value (Vr).