KR19980020554A - Electric rice cooker and its control method - Google Patents

Abstract

The present invention relates to an electric rice cooker and a method of controlling the same, after the preheating step of the rice cooker senses the temperature inside the rice cooker, and compares the temperature and the reference temperature stored in the microcomputer for the time corresponding to the temperature difference reference heating time An electric cooker and a control method for determining the cooking amount by correcting the total heating time by adding to or 뺌, have an effect of determining the correct cooking amount and determining the heater output amount accordingly.

Description

Electric rice cooker and its control method

The present invention relates to an electric rice cooker and a control method thereof, and in more detail, after the preheating step of the electric rice cooker is sensed by adjusting the total heating time by sensing the temperature inside the rice cooker with a temperature sensor, and also determining the correct cooking amount. The present invention relates to an electric rice cooker capable of controlling a boiling step and the like suitable for the cooking amount and a control method thereof.

In general, the configuration of the electric rice cooker, as shown in Figure 1, the power supply unit for supplying a constant power from the power source to the microcomputer (Micro Computer), the heater driving unit for supplying power to the cooking heater (Heater) under the control of the microcomputer and A key input unit for accepting the user's key input, a display unit for displaying the user's key input situation or cooking stage, a temperature sensor unit for sensing the temperature of the cooked food in the cooker and sending it to the microcomputer; It is composed of a microcomputer that a predetermined program (Program) is built so that such a control or operation process occurs.

The control method of the conventional electric rice cooker having such a configuration, as can be seen in the cooking curve of Figure 2, according to each cooking step so that the appropriate fire power is supplied to the cooker through the heater, preheating step, heating step, boiling step, moxibustion step It is divided into two. Here, the preheating step is performed by applying power to the heater for a predetermined time (t1) and then stopping power supply to the heater for a predetermined time (t2), and the heating step takes time to reach the temperature of the designated rice cooker (y ℃). (t3) is counted, and the cooked amount of the rice cooker is determined by comparing the counted time (t3) and the reference time previously stored in the microcomputer, and the boiling step uses a constant firepower for a predetermined time (t4) according to the determined cooked amount. In the rice cooker, the moxibustion step is to complete the cooking by stopping the thermal power supply for a specified time (t5), where the X-axis of Figure 2 represents the time of the Y-axis cooker temperature.

In the above description, when the microcomputer further describes the heating step of determining the cooking amount of the rice cooker, as shown in FIG. 2, the total time t3 taken to increase the temperature of the rice cooker to y ° C. after the heating step starts is counted. After that, the time t3 is compared with the reference time previously stored in the microcomputer, and the cooking amount of the rice cooker is determined according to the cooking amount allocated to each reference time, and the cooking time is again provided to the rice cooker in the boiling step based on the cooking amount. The total output of the heater to be determined. The concept thereof is shown in Table 1 below.

TABLE 1

Determination of Cooking Range of Electric Rice Cooker and Total Output of Heater in Boiling Process

For example, the determination of the cooking quantity according to the above Table 1 and the total output of the heater in the boiling step will be described. For example, if the time taken to reach y ° C. in the heating step after the preheating step is large is-large. The microcomputer judges the cooking amount as large compared to the reference time memorized in advance, and operates the heater driving unit so that the heater output is large in the subsequent boiling step, and if the time taken to reach y ℃ is small, If small, the microcomputer judges the cooking amount as small compared with the reference time stored in advance, and determines the cooking amount by driving the heater driving unit so that the heater output amount becomes small in the subsequent boiling step. .

However, the control method of the conventional electric rice cooker as described above does not consider the temperature at the time when the rice and water was first put into the electric rice cooker has caused some problems. For example, when 1 liter of water at 0 ° C is heated for 1 minute with 300 ° C of thermal power, the final temperature of the water is different from the final temperature of 1 liter of water at 50 ° C with 300 ° C of thermal power for 1 minute. It is easy to see the fact: (If the boiling time of the two waters is infinite, the final temperature will be similar, but it is unreasonable to do so because of time constraints or increased power consumption.) The temperature at the time of adding rice and water is different depending on the situation, and thus the cooking temperature in the cooker after the completion of preheating is also different. However, conventionally, as shown in Table 2, the heating time required for the internal temperature of the rice cooker to reach y ° C is large under the assumption that the initial temperature of the cooked water is constant at medium (Table 2 in Table 2). The heating time was divided into small, medium, and small, and the corresponding cooking amount was determined by comparing the heating time with a reference time previously stored in the microcomputer. However, as shown in the following Table 2, various problems may occur when the initial temperature of the cookware is high or low.

TABLE 2

Relationship between the cooking quantity determined by the temperature and cooking time

For example, when the temperature of the cooked food is high in the first rice cooker, but the actual amount of cooking is large, the heating time (t3) taken to reach a constant temperature y ° C in the heating step of the cooker is the temperature of the first cooked food. Because of the high time t3 to y ° C. will be further shortened. Therefore, the microcomputer judges the cooking amount as the medium or small cooking amount rather than the large by the shortened time t3, and the thermal power determined by the cooking amount is applied to the rice cooker during the boiling step. Will be supplied.

However, because the actual amount of cooking is large (large), there is a problem that can not be cooked properly. In other words, although not described in all the examples above, as shown in Table 2, when the temperature of the first cooking product is low or high rather than medium, the thermal power supply reflecting the actual cooking amount is not supplied. It will be easy to see.

An object of the present invention is to devise to solve the conventional problems as described above, by sensing the temperature inside the rice cooker after the preheating step of the electric rice cooker, and compares the temperature and the reference temperature previously stored in the microcomputer and The rice cooker and its control method can be determined by determining the heating time and cooking amount in consideration of the difference ΔT ° C and determining the output amount of the heater to be supplied in the boiling step of the next step. To provide.

1 is a block diagram of a general electric cooker.

Figure 2 is a cooking curve showing the cooking stage of the electric cooker.

Figure 3 is a flow chart showing a control method of the electric rice cooker according to the present invention.

The configuration of the present invention for achieving the above object is a power supply unit for supplying a constant power from the power supply to the microcomputer, a heater drive unit for supplying power to the cooking heater under the control of the microcomputer, and accepts the user's key input A key input unit, a display unit for displaying the user's key input status or cooking stage, a temperature sensor unit for sensing the temperature of the cooked food in the cooker and sending it to the microcomputer, and a predetermined program is built so that the above control or calculation process occurs. It is characterized by the made microcomputer.

In addition, the control method of the electric rice cooker to achieve the above object, the step of initializing all memory variables when the power is applied (S1), and by turning on the power to the heater to a predetermined temperature to preheat the cooker and then turn on the power of the heater Turning off for a predetermined time (S2), sensing the temperature inside the cooker by a temperature sensor (S3), comparing the detected temperature with a previously stored reference temperature (S4) and the temperature difference A heating time correction step (S5) of correcting the total heating time by adding or subtracting the time to the reference heating time, a heating step (S6) of applying power to the heater according to the corrected heating time, and the total heating time. The cooking amount determination step (S7) of sensing and comparing the time with the reference heating time stored in the microcomputer to determine the cooking amount of the rice cooker, and determines the heater output amount according to the determined cooking amount and outputs the heater. Key is made of an a boiling step (S8), and a step (S9) to the steam by turning off the power of the heater and to its features.

Another embodiment of the present invention for achieving the above object, the command means for initializing all the memory variables when the power is applied, and by heating the power to the heater to a predetermined temperature to preheat the cooker after a predetermined time Command means for sensing the temperature inside the cooker by means of a temperature sensor, and comparing the detected temperature with a previously stored reference temperature and adding or subtracting the time corresponding to the temperature difference to the reference heating time. Command means for correcting the heating time, command means for applying power to the heater according to the corrected heating time, and the cooking amount of the cooker by detecting the total heating time and comparing the time with the reference heating time stored in the microcomputer Command means for determining a heater output amount according to the determined cooking quantity and outputting a heater; The computer memory as they are made for the instruction means and moxibustion off power to the heater group as its features.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

1 shows an electric circuit configuration of the present invention, wherein a power supply unit for supplying a low voltage constant DC power supply to a microcomputer from a high voltage AC power supply is connected, and the transistor is configured to supply power to the cooking heater under the control of the microcomputer. And a heater driver made of a combination of a relay and a relay (not shown). On the other hand, the user is provided with a key input unit for key input and a display unit in a digital display format for displaying the key input or cooking step to the user, and the temperature sensor unit is connected to detect the temperature in the rice cooker for each cooking step The microcomputer has an analog / digital converter for processing the signal of the temperature sensor unit, and a predetermined program is embedded in a read only memory (ROM) to perform the above process.

On the other hand, Figure 2 is a cooking curve according to the present invention, it can be seen that divided into preheating step, heating step, boiling step, steaming step and the like. Here, the preheating step is performed by applying power to the heater for a predetermined time (t1) and then stopping the power supply to the heater for a predetermined time (t2), and the heating step detects the temperature of Ta and corrects the heating time. The cooking time of the rice cooker is determined by counting the time t3 to reach the temperature of the rice cooker (y ° C.) and comparing the counted time t3 with the reference heating time previously stored in the microcomputer. Here, the boiling step is to provide a constant firepower to the rice cooker for a certain time (t4) according to the determined cooking amount, the moxibustion step is to complete the cooking by stopping the heating power for a specified time (t5). Here, the X-axis of Figure 2 represents the temperature of the rice cooker Y-time.

3 is a flowchart illustrating a control method of an electric rice cooker according to the present invention, when power is applied by an operator, the microcomputer initializes all memory variables, sends a signal to the heater driving unit, and preheats the rice cooker to a predetermined temperature, followed by a heater driving unit. Will turn off the operation for a certain time. Soon the microcomputer detects the temperature Ta inside the cooker by the temperature sensor and compares the value with the reference temperature previously stored in the microcomputer, and adds the time corresponding to the temperature difference ΔT ℃ to the reference heating time or By subtracting, the total output time of the heater is controlled. In summary, it is shown in Table 3 and Table 4.

TABLE 3

Standard heating time by reference temperature

TABLE 4

Correction of heating time to the temperature Ta inside the cooker

Here, NB, NM, NS, ZO, PS, PM, and PB are terms of fuzzy theory, respectively, meaning negative big, negative middle, negative small, zero, positive small positive middle, and positive big.

Here, Ta increases further by + ΔT ° C at any reference temperature if the temperature in the cooker is high, and drops further by -ΔT ° C at any reference temperature when the temperature is low. In other words, when the temperature Ta in the rice cooker is high, the total heating time t3 is shorter than the time at the cooking amount of the reference amount, and when the temperature is low, it is longer than the time at the cooking amount of the reference amount. Therefore, if the temperature Ta in the rice cooker is high, the heating time t3 becomes smaller than the reference amount. On the contrary, when the temperature Ta in the rice cooker is low, the heating time becomes larger than the reference amount, so that the heating time of the heater as shown in Table 4 is detected by detecting the temperature as -ΔT ℃ of Ta and the reference heating time of the heater shown in Table 3. To further reduce.

In addition, the micom determines the cooking amount corresponding to the determined total heating time to properly determine the output amount of the heater in the boiling step, and finally to turn off the power of the heater to complete the cooking.

Therefore, the present invention corrects the total heating time of the cooker by detecting the temperature Ta of the cooker after the preheating step and comparing the temperature with the standard heating time of the cooker, and accordingly, the correct cooking amount is determined, and the correct heater boils the output amount. There is an effect that can be provided in the process.

Claims (7)

A power supply unit for supplying power, a heater driving unit for supplying power to the cooking heater, a key input unit for accepting the user's key input, a display unit for displaying the user's key input status or cooking step, and the cooking temperature in the cooker Electric rice cooker comprising a temperature sensor unit for detecting the power supply unit, a heater driving unit, a display unit, a microcomputer with a predetermined program to control the temperature sensor unit. Initializing all memory variables when the power is applied, turning on the heater to a predetermined temperature, preheating the cooker, turning off the heater for a predetermined time, and detecting the temperature inside the cooker by a temperature sensor. And a heating time correction step of correcting the total heating time by comparing the detected temperature with a previously stored reference temperature and adding or subtracting a time corresponding to the temperature difference to a reference heating time, and a heater according to the corrected heating time. A heating step of applying power to the heating unit; a cooking amount determining step of detecting the cooking amount of the rice cooker by detecting the total heating time and comparing the time with the reference heating time stored in the microcomputer; and the heater according to the determined cooking amount A boiling step of determining an output amount and outputting a heater, and turning off the power of the heater to draw steam Control method of an electric rice cooker. The method according to claim 2, wherein the cooking amount determination step, having a temperature inside the rice cooker after the preheating step of the rice cooker, and comparing the temperature and the reference temperature stored in the microcomputer to reference the time corresponding to the temperature difference reference heating time A method of controlling an electric cooker, characterized in that the cooking amount is determined by correcting the total heating time by adding to or 뺌. The method of claim 2, wherein the step of correcting the heating time adds ΔT ℃ to the reference temperature when the temperature sensed by the temperature sensor is smaller than the reference temperature stored in the microcomputer and adds the time corresponding to the added temperature to the heating time. In addition to the control method of the electric cooker characterized in that made in. The method according to claim 2 or 4, wherein the step of correcting the heating time is further subtracted from the reference temperature by ΔT ° C if the temperature sensed by the temperature sensor is larger than the reference temperature stored in the microcomputer. The control method of the electric rice cooker characterized in that the time corresponding to the temperature lowered by further reducing the heating time. The control method of an electric rice cooker according to claim 6, wherein the boiling step is supplied with a pre-stored heater output amount in accordance with the total heating time detected in the preceding heating step and the cooking amount allocated to each heating time. Command means for initializing all memory variables when power is applied, command means for turning on the heater to a certain degree, preheating the cooker, and then turning off the heater power for a certain time, and temperature inside the cooker by a temperature sensor. Command means for sensing, command means for correcting the total heating time by comparing the sensed temperature with a previously stored reference temperature and adding or subtracting a time corresponding to the temperature difference to the reference heating time, and according to the corrected heating time. Command means for applying power to the heater, command means for detecting the total heating time and comparing the time with the reference heating time stored in the microcomputer and determining the cooking amount of the rice cooker, and the heater output amount according to the determined cooking amount Command means for deciding and outputting the heater, and command means for turning off the power of the heater to induce moxibustion. Computer memory for which it is characterized.