KR20010069111A - Method for controlling heat of electric rice-cooker - Google Patents

Abstract

PURPOSE: A warm keeping control method for an electric rice cooker is provided to compensate warm keeping temperature according to a warm keeping rate per stage by deciding if the warm keeping rate is more than a specific rate. CONSTITUTION: To control the warm keeping of an electric rice cooker, a controller keeps the electric rice cooker warm according to a warm keeping condition per stage. After some time, the controller decides if a warm keeping rate is more than a specific rate, per stage. When the warm keeping rate is less than the specific rate, the controller senses the predetermined warm keeping temperature at the stage and resets the temperature according to the predetermined warm keeping temperature. Finally, the controller keeps the electric rice cooker warm by the reset temperature.

Description

Method for controlling heat of electric rice cooker {Method for controlling heat of electric rice-cooker}

The present invention relates to an electric rice cooker, and more particularly, to a method for controlling heat of an electric rice cooker.

The conventional electric rice cooker, as shown in Figure 1, the first temperature sensing unit 10 for sensing the temperature of the rice cooker, the second temperature sensing unit 50 for detecting the ambient temperature, and the second temperature Drive control by receiving the output of the variable drive control unit 60 for outputting a control signal according to the ambient temperature sensed by the sensing unit 50, the first temperature sensing unit 10 and the variable drive control unit 60 The comparison determination unit 20 for outputting a signal, the first drive unit 30 for heating the side of the rice cooker according to the output of the comparison determination unit 20, and the rice cooker according to the output of the comparison determination unit 20 It consists of a second drive unit 40 for heating the bottom of.

The first temperature sensing unit 10 includes a temperature sensor BS1 having a resistance value varied according to an internal temperature of the cooker, first and second resistors R1 and R2 connected in parallel to the temperature sensor BS1, The third resistor R3 is connected to the temperature sensor BS1 in series.

The comparison determination unit 20 receives the output of the temperature sensor BS1 as a negative (−), and receives the divided voltage values of the first and second resistors R1 and R2 as positive (+). A comparator 21 for outputting a signal according to the result, an inverter 24 for inverting the output of the variable driving controller 60, and outputs of the comparator 21 and the inverter 24 are inputted to perform an AND operation. The first AND gate 22 performs an input, and the second AND gate 23 receives an output of the comparator 21 and the variable driving controller 60 and performs an AND operation.

The first driver 30 is driven based on whether the conduction is determined by receiving the output of the first AND gate 22 as a base and whether the conduction of the first transistor Q1 is conducted. It is composed of a first photocoupler (PC) is determined. Here, reference numerals denote the fourth and fifth resistors R4 and R5 and the sixth resistor R6.

The second driver 40 is driven based on the conduction of the second transistor Q2 and the conduction of the second transistor Q2, which are connected with the output of the second AND gate 23 as a base. It is composed of a second photo coupler (PC) is determined. Here, reference numerals denote the sixth and seventh resistors R6 and R7 and the eighth resistor R8.

The second temperature sensing unit 50 includes a temperature sensing unit CS1 for sensing an ambient temperature, tenth and eleventh resistors R10 and R11 connected in parallel to the temperature sensing unit CS1, and the temperature. The twelfth resistor R12 connected in series to the sensing unit CS1, the thirteenth and fourteenth resistors R13 and R14, and the fifteenth and sixteenth resistors R15 and R16 are included.

The variable driving controller 60 receives a sensed value of the temperature sensing unit CS1 at a positive (+) end and negatively divides the partial pressure values of the tenth and eleventh resistors R10 and R11. The second comparator 61 and the sensing value of the temperature sensing unit CS1 are positively input to receive the second comparator 61 and output the comparison result, and the thirteenth and fourteenth resistors R13 and R14 are received. A third comparator 62 for receiving a voltage divider resistance value of-as a negative value and outputting a comparison result thereof, and a sensed value of the temperature detector CS1 as a positive value, A fourth comparator 63 for receiving the divided voltage value of the sixteenth resistors R15 and R16 to a negative terminal and outputting a comparison result, and a second inverting the output of the second comparator 61; The input operation of the inverter 70, the third inverter 71 for inverting the output of the third comparator 62, and the outputs of the second inverter 70 and the third comparator 62 is performed to perform an AND operation. A fourth end gate 64 which receives an output of the third end gate 64, the outputs of the second and third inverters 70, 71, and the fourth comparator 63 and performs an AND operation; First to third duty counters 66, 67, 68 for receiving the outputs of the second comparator 61, the third end gate 64, and the fourth end gate 65, respectively, and outputting different duty ratio signals. ) And the output of the first to third counters 66, 67 and 68 to perform orr operation, and output the result to the first and second end gates 22 and 23. Or gate 69.

Referring to the operation of the thermostat of the electric rice cooker according to the prior art configured as described above are as follows.

The comparison determination unit 20 receives the cooker bottom temperature sensed through the first temperature sensing unit 10 based on the partial pressure values of the first and second resistors R1 and R2, that is, the detected temperature. If the temperature is lower than the temperature, the first comparator 21 outputs a high level signal as shown in FIG. 2A, and the first to third counters 66 as shown in FIGS. 2B to 2D. When the output of the first AND gate 22 becomes high according to the output signal of the 67 and 68, the first driver 30 is driven to heat the side of the rice cooker.

That is, the comparison determination unit 20 compares the temperature detected by the first temperature detection unit 10 with the reference temperature to drive the first driving unit 30 only when the detection temperature is lower than the reference temperature.

On the other hand, if the warming temperature of the rice cooker is lower than the reference temperature, it is divided into three steps according to the ambient temperature as follows, so that the side is heated more than the bottom to compensate for the cooling of the side when the ambient temperature is low.

First, when the output voltage V from the second temperature detector 60 is greater than the first reference voltage Vref1, the ambient temperature is high. Therefore, a high signal is output from the second comparator 61. Accordingly, the first duty counter 66 is enabled to output only the signal of the first duty counter 66 through the or gate 69. In this case, as shown in FIG. 2B, the duty ratio output from the first counter 66 is 50:50 so that the side and the bottom are heated equally.

Second, when the output voltage V output from the second temperature detector 60 is less than the first reference voltage Vref1 and is greater than the second reference voltage Vref2, the ambient temperature is slightly lower. At 64, a high signal is output, whereby the second counter 67 is enabled to output only the signal of the second counter 67 via the or gate 69. At this time, the duty ratio output from the second duty counter 67 heats the side surface slightly more than the bottom at 40:60, as shown in FIG. 2C.

Third, when the output voltage V output from the second temperature detector 50 is greater than the third reference voltage Vref3 and less than the second reference voltage Vref2, the ambient temperature is much lower. A high signal is output from the AND gate 65, and accordingly, the third duty counter 68 is enabled to output only the signal of the third duty counter 68 through the or gate 69. At this time, the duty ratio output from the third duty counter 68 heats the side much more than the bottom at 30:70 as shown in FIG. 2D.

As described above, the insulation control apparatus of the electric rice cooker according to the prior art sets the duty ratio of the first to third duty counters 66, 67, 68 to 50: 50, 40: 60, 30: 70. When the ambient temperature is higher than the reference temperature, the first duty ratio 50: 50 is selected to heat the bottom and the side at the same time, and when the ambient temperature is slightly lower than the reference temperature, the second duty ratio 40: 60 is selected. Select to heat the side slightly more than the floor, if the ambient temperature is much lower than the reference temperature, select the third duty ratio (30: 70) to heat the side more than the floor.

Therefore, by changing the drive time of the bottom and side of the cooker according to the ambient temperature is to maintain the same temperature of the bottom.

As described above, the insulation control apparatus of the electric rice cooker according to the prior art has the following problems.

First, by varying the heating time of the bottom and side of the rice cooker by using a duty ratio that varies depending on the ambient temperature change, if the ambient temperature is abnormal high or abnormal low temperature, a stable thermal insulation process is not made.

Second, the manufacturing cost increases because the ambient temperature sensing unit for detecting the ambient temperature must be added separately.

The present invention has been made to solve this problem, it is possible to compensate for the warming temperature in accordance with the step-by-step performance by determining whether the warming performance ratio in the standard warming condition is more than a predetermined ratio according to the preset multi-stage warming conditions The purpose of the present invention is to provide a method of controlling heat of an electric rice cooker.

1 is a view showing a thermal control circuit of an electric rice cooker according to the prior art

2A to 2D are waveform diagrams illustrating output waveforms of the comparison determination unit and the variable driving controller shown in FIG. 1.

3 is a flow chart illustrating a method for controlling heat of an electric rice cooker according to the present invention.

Insulation control method of the electric rice cooker according to the present invention for achieving the above object is the step of performing the warming process according to the pre-set multi-stage warming conditions, the predetermined multi-stage warming condition after a predetermined time after performing the warming process Determining whether the performance ratio in the normal operation condition is greater than or equal to a predetermined ratio; and if the performance ratio is less than or equal to the predetermined ratio, detecting the predetermined multi-stage thermal insulation process performance ratio; and according to the detected thermal insulation process performance ratio. And resetting the warming temperature, and controlling the warming process according to the reset warming temperature.

Hereinafter, the step-by-step thermal insulation conditions set in advance before explaining the method of controlling the insulation of the rice cooker according to the present invention will be described with reference to the following table.

step Rice cooker temperature floor side Top Rice temperature W1 64 ℃ 0 sec 3 One 74 ℃ W2 63 0 6 2 73 W3 62 0.2 9 3 72 (target) W4 61 One 12 4 71 W5 60 2 15 5 70

That is, on the basis of the warming condition of the third step (W3), when the temperature of the rice cooker increases, the heating time of the upper portion rather than the bottom and the side increases, and when the temperature of the cooker decreases, the heating time of the bottom, side, and upper portion Increase.

Hereinafter, with reference to the accompanying drawings, the thermal control method of the electric rice cooker according to the present invention in more detail.

3 is a flow chart illustrating a method for controlling heat of an electric rice cooker according to the present invention.

Referring to FIG. 3, first, an insulation process is performed according to the insulation conditions for each of the first to fifth steps W1 to W5.

Subsequently, it is determined whether the first set time has elapsed after performing the warming process (S2).

As a result of the determination (S2), if the first set time has elapsed, it is determined whether the warming condition of the third predetermined step (W3) has been reached (S3).

In operation S4, it is determined whether the measured execution ratio in the third step W3 is greater than or equal to a predetermined ratio 70.

Subsequently, when the determination result (S4), the measured execution ratio in the third step (W3) is more than a predetermined ratio (70), it is determined as a normal temperature condition and the thermal insulation process is performed at a reference temperature (72 ° C.).

On the other hand, when the determination result (S4), the execution ratio in the measured third step (W3) is less than the predetermined ratio 70, the execution ratio (W1 + W2) in the first step (W1) and the second step (W2) It is determined whether or not it has a value larger than the execution ratio W4 + W5 in the fourth step W4 and the fifth step W5 (S6).

Subsequently, the determination result S6, the execution ratio W1 + W2 in the first step W1 and the second step W2 is performed in the fourth step W4 and the fifth step W5 ( If the value is larger than W4 + W5), it is determined whether the execution ratio in the first step W1 has a value greater than the execution ratio in the second step W2 (S7).

As a result of the determination (S7), when the warmth operation rate of the first step W1 has a value greater than the warmth operation rate of the second step W2, the first set temperature (2 ° C.) is higher than the preset reference temperature. It is raised to and reset (S8).

On the other hand, when the determination result (S7), the execution ratio in the first step (W1) has a value smaller than the execution ratio in the second step (W2), the second set temperature (1 ℃) higher than the preset reference temperature It is raised to and reset (S9).

Subsequently, the determination result S6, the execution ratio W1 + W2 in the first step W1 and the second step W2 is performed in the fourth step W4 and the fifth step W5 ( If it is smaller than W4 + W5), it is determined whether the execution ratio in the fourth step W4 has a value smaller than the execution ratio in the fifth step W5 (S10).

As a result of the determination (S10), when the execution ratio in the fourth step W4 has a value smaller than the execution ratio in the fifth step W5, the first set temperature (2 ° C.) is lower than the preset reference temperature. It is lowered and reset to (S11).

On the other hand, when the determination result (S1), the execution ratio in the fourth step (W4) has a value larger than the execution ratio in the fifth step (W5), the second set temperature (1 ℃) lower than the preset reference temperature The temperature is lowered and reset (S12). Subsequently, when the second set time has elapsed, the process returns to the initial routine (S13).

As described above, the insulation control method of the electric rice cooker according to the present invention can compensate the insulation temperature according to the performance ratio in the pre-set insulation step conditions.

As described above, the method of controlling heat of an electric rice cooker according to the present invention has the following effects.

First, since the temperature can be compensated according to the performance ratio in the step-by-step thermal insulation conditions without adding a separate temperature sensor, the manufacturing cost can be lowered.

Second, it is possible to maintain a constant warming temperature by compensating the temperature according to the performance ratio in the warming condition irrespective of the ambient temperature.

Third, it is possible to improve the taste by maintaining a constant warming temperature.

Claims (6)

Performing a thermal insulation process according to the preset thermal insulation conditions; Determining whether an execution ratio in a normal operation condition among preset thermal insulation conditions is greater than or equal to a predetermined ratio when a predetermined time elapses after performing the thermal insulation process; Detecting a performance ratio of the preset multi-stage insulation process when the performance ratio is less than or equal to a predetermined ratio; Resetting the warming temperature according to the detected warming process execution ratio; And, Insulation control method of an electric rice cooker comprising the step of controlling the warming process according to the reset warming temperature. The method of claim 1, The predetermined ratio is 70. The method of controlling insulation of an electric rice cooker. The method of claim 1, Detecting the performance ratio for each stage Performance ratio in the warmth condition of the fourth and fifth stages in which the sum of the performance ratios in the warmth conditions of the first and second stages preset to a temperature lower than the normal warmth operating condition is set to a temperature higher than the normal warmth operating conditions Determining whether the value has a value greater than the sum; If the sum of the performance ratios in the warming conditions of the first and second stages is greater than the sum of the performance ratios in the warming conditions of the fourth and fifth stages, the performance ratio in the warming conditions of the first stage is Judging whether it has a value greater than the performance ratio in the step 2 of keeping warm, If the sum of the performance ratios in the warming conditions of the first and second stages is less than the sum of the performance ratios in the warming conditions of the fourth and fifth stages, the performance ratio in the warming conditions of the fourth stages is insulated in the fifth stages. Insulation control method of an electric rice cooker characterized in that it comprises a step of determining whether or not having a value greater than the performance ratio in the conditions. The method according to claim 1 or 3, Resetting the warming temperature according to the detected performance ratio Setting the first predetermined temperature higher than the reference temperature if the performance ratio of the first step is equal to or greater than the performance ratio of the second step; Setting the temperature to a second predetermined temperature higher than a reference temperature if the performance ratio of the first step is less than or equal to the performance ratio of the second step; Setting the temperature to a first predetermined temperature lower than a reference temperature when the performance ratio of the fourth step is less than the performance ratio of the fifth step; If the performance ratio of the fourth step is equal to or greater than the performance ratio of the fifth step, the thermal control method of the electric rice cooker characterized in that the step of setting to a second predetermined temperature lower than the reference temperature. The method of claim 4, wherein And the first predetermined temperature and the second predetermined temperature satisfy a first predetermined temperature > second predetermined temperature condition. The method of claim 1, If the performance ratio in the normal operating condition is more than a predetermined ratio, the heat insulation control method of the electric rice cooker characterized in that it further comprises the step of determining the normal condition to maintain the reference temperature.