JP4073825B2 - Electric rice cooker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
[0002]
  The present invention relates to a configuration of an electromagnetic induction heating type electric rice cooker in which one rice cooker is heated and driven by a plurality of work coils.
[Prior art]
[0003]
  Conventionally, in this type of electric rice cooker, a plurality of work coils for heating the same rice cooker, for example, the first work coil L1 on the rice cooker bottom side and the second work coil L2 on the rice cooker side side are heated and controlled. In this case, a circuit for detecting the electric power for each of the work coils, a feedback circuit for feeding back the detected electric power, and variably controlling the drive output of each work coil based on the electric power value fed back through the feedback circuit. A plurality of systems for controlling the work coil drive are provided and individually controlled (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
          Japanese Patent Laid-Open No. 11-56602 (page 1-5, FIG. 1)
[Problems to be solved by the invention]
[0005]
  However, as described above, providing a power detection circuit and a feedback circuit for each work coil of a plurality of work coils complicates the control system, increases the circuit cost, and increases the failure factor. is there.
[0006]
  The present invention has been made to solve such a problem. The primary current of the work coil drive power supply circuit is detected to determine the amount of power, and a single feedback circuit can be used for a plurality of work coils. An object of the present invention is to provide an electric rice cooker that solves the above-mentioned problems by feedback controlling the output.
[Means for Solving the Problems]
[0007]
  In order to achieve such an object, the present invention includes the following effective problem solving means.
[0008]
  (1) First problem solving means (Invention of Claim 1)
  According to a first aspect of the present invention, there are provided a plurality of work coils for heating a rice cooker, a power supply circuit, and a plurality of work coil drive circuits for driving the plurality of work coils with a predetermined power via the power supply circuit. And an electric rice cooker comprising drive control means for driving or controlling the plurality of work coils individually or simultaneously via the work coil drive circuits, and a current for detecting a current value on the primary side of the power supply circuit A detecting means is provided, and the heating power of each of the plurality of work coils is controlled using a single feedback circuit based on the current value detected by the current detecting means.The heating control process for controlling the output is a heating control process in which a plurality of work coils are driven simultaneously, and the plurality of work coils includes a first work coil and a second work coil. Control is performed by fixing the output of one of the work coils to a predetermined output value and varying the output value of the other work coil.It is characterized by that.
[0009]
  According to such a configuration, only one system is sufficient for both the power detection circuit and the power feedback circuit, the circuit configuration is simple, and the cost of the apparatus can be reduced.When simultaneously driving, the output of one work coil can be fixed at a predetermined output value, and the output value of the other work coil can be made variable. The output value can be grasped, the heating power of each of the plurality of work coils can be controlled, and the total output value can be changed.
[0010]
  (2) No.2Problem solving means (claims)2Invention)
  First of this invention2The problem solving means is1In the configuration of the problem solving means, the output of the first work coil is larger than the output of the second work coil, and the control of the heating output is performed by fixing the output of the second work coil having a small output, It is characterized in that it is configured to change the output of the large first work coil.
[0011]
  When the work coil is employed as a heating means, it does not function effectively as an electromagnetic induction heating means unless there is an output of a predetermined size at a minimum.
[0012]
  Therefore, when the first and second sets of work coils are driven at the same time, the heating output adjustment control is performed by first adjusting the output of the second work coil having a smaller output to a predetermined required magnitude. Then, the output of the first work coil having a larger output is adjusted by varying it.
[0013]
  (3) No.3Problem solving means (claims)3Invention)
  First of this invention3The problem solving means is2In the configuration of the problem solving means, the second work coil is characterized in that the heating amount is adjusted only by time-division control.
[0014]
  When the output of the second work coil having a small output is made constant, the heating amount of the second work coil is appropriately adjusted only by the time division control.
【The invention's effect】
[0015]
  As a result, according to the electric rice cooker of the present invention, the power detection circuit and the feedback circuit are only one system, the apparatus cost is low, and the power adjustment is simple. Moreover, since the failure factor is reduced, the reliability of the product is improved. Furthermore, since the power detection is a system that detects the total power of each work coil, the control accuracy within the rated power value when a plurality of work coils are simultaneously operated becomes high.
DETAILED DESCRIPTION OF THE INVENTION
[0016]
  (Embodiment 1)
  1-6 has shown the structure and effect | action of the electromagnetic induction heating-type electric rice cooker which concerns on Embodiment 1 of this invention provided with the some work coil.
[0017]
  (Configuration of rice cooker body and lid unit)
  First, FIG. 1 shows a basic configuration of a rice cooker body and a lid unit portion of the electric rice cooker.
[0018]
  That is, as shown in FIG. 1, the electric rice cooker is generally composed of a rice cooker (inner metal material) made of a magnetic metal material (iron-based metal material) such as a stainless steel material capable of self-heating by an eddy current induced therein. 2), an inner case (protective frame) 4 made of a synthetic resin formed into a bottomed cylindrical shape so that the rice cooker 2 can be arbitrarily stored and set, and an outer casing that holds the inner case 4 Covering the opening of the cylindrical outer case 5 and the upper portion of the rice cooker main body 1 formed in a bottomed cylindrical body with the upper portion opened by combining and integrating the outer case 5 and the inner case 4 It is comprised from the cover unit 3 provided so that opening and closing was possible.
[0019]
  On the bottom wall of the inner case 4, for example, a first work coil L for heating rice cooker that is concentrically wound at different positions inside and outside in the radial direction.₁And the first work coil L₁Is heated uniformly as much as possible by heating the central surface side and the side surface side of the bottom part 2a of the rice cooker 2 accommodated in the inner case 4 efficiently and cooks rice efficiently. ing. Further, on the outer surface near the upper side of the side wall portion of the inner case 4, a second work coil L for heat insulation is further provided.₂And the second work coil L₂Is configured to heat the side surface 2b of the rice cooker 2 mainly during heat insulation.
[0020]
  The outer case 5 is composed of a cylindrical cover member and a bottom member formed of, for example, a synthetic resin plate in the vertical direction, and heats a heat radiating plate 32 inside the lid unit 3 to be described later on the inside of the shoulder portion. A shoulder heater H as a heating means is provided corresponding to the peripheral edge 32a.
[0021]
  On the other hand, the lid unit main body 31 portion of the lid unit 3 is composed of, for example, an outer cover and an inner cover made of synthetic resin, and the inner space is formed in a hollow heat insulating structure, although not shown.
[0022]
  And the heat sink 32 mentioned above is provided in the downward direction of this cover unit main body 31, for example so that attachment or detachment is possible. Further, a pressure adjusting port is formed in the central portion of the lid unit main body 31 so as to penetrate in both the upper and lower directions, and the pressure adjusting unit 33 is detachably fitted to the pressure adjusting port from above.
[0023]
  Moreover, although not shown in figure, the predetermined | prescribed operation panel part is provided above the front-surface part of the said rice cooker main body 1. FIG. The operation panel unit includes, for example, a liquid crystal display unit, a rice cooker switch, a timer reservation switch, a cancel switch, a heat retention / reheating switch, a fake switch, a menu operation switch, an hour switch, a minute switch, and various operation switches (parts thereof) Touch key portion) is provided.
[0024]
  (Configuration of the rice cooker body side control circuit)
  Next, FIG. 2 shows a configuration of an electrical control circuit portion centering on the rice cooker main body 1 side configured as described above and the microcomputer control unit 10 for heat retention control.
[0025]
  In the figure, reference numeral 10 denotes a rice cooker / heat retention control microcomputer control unit (CPU) which is configured to include rice cooker heating control means, heat insulation heating control means, rice cooker temperature determination means, rice cooker detection means, buzzer notification means, and the like. The microcomputer control unit 10 is configured around a microcomputer, for example, a temperature detection circuit section of the rice cooker 2, first and second work coils L₁, L₂Drive control circuit unit, rice cooker 2 presence / absence detection circuit unit, oscillation circuit unit, reset circuit unit, heat insulation heater drive control circuit unit, buzzer notification unit, power supply circuit unit, and the like.
[0026]
  And first, in the temperature detection part 13 provided corresponding to the temperature detection sensor 7 by the side of the bottom wall part 2a of the said rice cooker (inner pan) 2, the bottom wall part of the rice cooker 2 by the said temperature detection sensor 7, for example The temperature detection signal 2a is input.
[0027]
  The first and second work coil drive control circuit units include first and second IGBT drive circuits 21 and 22, first and second IGBTs 23 and 24, and first and second resonance capacitors C, respectively.₁, C₂Etc. are formed. And by controlling the said 1st, 2nd IGBT drive circuits 21 and 22 by the 1st, 2nd work coil drive control circuit part of the said microcomputer control unit 10, said process according to each process of a rice cooking process 1st and 2nd work coil L₁, L₂ON / OFF relationship and ON wattage at ON, and ON duty ratio (for example, n seconds / T seconds) at the same wattage, respectively, by appropriately changing the heating temperature of the rice cooker 2 in each step of the rice cooking process And the heating pattern is appropriately controlled in consideration of the amount of cooked rice, and the cooked rice is cooked without uniform water absorption and heating unevenness, and appropriate heating output control is performed to achieve the subsequent heat retention. It has become.
[0028]
  In this embodiment, the first and second work coils L are used in those cases as shown in FIGS.₁, L₂Are driven individually or simultaneously as needed, and either one of these outputs or a combination of both outputs is appropriately combined to obtain a desired and sufficiently large heating output. The first and second work coils L suitable for the required heating amount for each of water absorption, temperature rise, cooking (maintain boiling), unevenness, and heat retention in the process.₁, L₂The output value and ON / OFF pattern are appropriately set and controlled.
[0029]
  In this control, the microcomputer control unit 10 performs the first through a power detection means comprising a current transformer 11 and a current detection circuit 12 for detecting the primary current of the work coil drive power supply circuit as shown in the figure. 1, the power during operation of the second work coil is detected, and the first power detection circuit, the first feedback circuit, and the first power detection circuit so that the same power value becomes a preset target power value. The second IGBT drive circuits 21 and 22 are feedback-controlled.
[0030]
  Further, by controlling the shoulder heater drive circuit by the shoulder heater drive control circuit section of the microcomputer control unit 10, for example, in the rice cooking or heat retention process, the output value of the shoulder heater H and the ON duty ratio at the same output value (for example, (n seconds / 16 seconds) are appropriately changed so that the heating temperature of the heat radiating plate 32 is appropriately variably controlled in each step of the rice cooking or heat retaining step (however, the shoulder heater H and the shoulder heater). The drive circuit is not shown because it is not the gist of the present invention.
[0031]
  Reference numeral 14 denotes an operation unit provided with various operation switch groups (rice cooking switch, timer reservation switch, cancel switch, heat retention / reheating switch, fake switch, menu operation switch, hour switch, minute switch) of the operation panel unit described above. When the necessary switches of the switch group are appropriately operated, the user's instruction content is recognized by the recognition means on the microcomputer control unit 10 side, and the desired rice cooking or A heat retaining heating output and a heating pattern are set, and the rice cooking heating control means or the heat retaining heating control means is appropriately operated to perform desired rice cooking or heat retaining.
[0032]
  Reference numeral 15 denotes the liquid crystal display unit described above. The liquid crystal display unit 15 displays necessary items such as a desired menu and time in response to the ON operation of each switch of the operation switch 14, and thereafter displays necessary items according to the set contents. It has become.
[0033]
  Further, reference numeral 8 is an AC power source, 9 is a rectifier circuit, Cs is a smoothing capacitor, and CL is a choke coil.
[0034]
  (Cooking rice control)
  Next, with reference to the flowchart of FIG. 3 and the time charts of FIGS. 4 and 5, the contents of basic rice cooking to heat retention control by the microcomputer control unit 10 will be described.
[0035]
  That is, as shown in the flowchart of FIG. 3, the control starts when the rice cooking switch is turned on.
[0036]
  And first, step S₁In the water absorption process, for example, the first work coil L₁Heating output of 1200 (W), the second work coil L₂The heating outputs are set to 200 (W) respectively (these numerical relationships are merely examples), and the first and second outputs are set so that the total output thereof is within the above-described allowable rated output 1400 (W). Work coil L₁, L₂Furthermore, the shoulder heater H is simultaneously driven to heat the whole rice cooker 2 to the water absorption temperature (40 to 45 ° C.). Then, water absorption heating at the same water absorption temperature is executed within a predetermined water absorption time while slightly adjusting the output with the same heating pattern.
[0037]
  Next, when the water absorption process is finished, the next step S₂To the second work coil L₂OFF, the first work coil L₁Is set to a maximum output of 1400 (W), and the first temperature rise heating is performed until the combined number determination in which a high heating output is required. And further step S_ThreeThen, the temperature detection sensor 7 detects the temperature of the rice cooker 2 and determines whether or not the temperature is equal to or higher than a predetermined reference number for determining the total number.
[0038]
  Then, in accordance with the result of the total number determination (large amount, medium amount, small amount), step S_FourGo to the second heating and heating step in the boiling state of, for example, the second work coil L₂OFF, first work coil L₁Performs heating with a heating pattern having a maximum output of 1400 (W). After that, when it is detected that the temperature of the rice cooker 2 has reached the boiling temperature of 100 ° C., step S is further performed._FiveThe process moves to the cooking process by maintaining the boiling, and this time the first and second work coils L₁, L₂Is maintained in a boiling state in an ON / OFF pattern by simultaneous driving within a total output of 1400 (W). As a result, rice is cooked over time.
[0039]
  Then, after determining whether or not the temperature of the rice cooker 2 is equal to or higher than the cooking completion temperature, step S₆1st and 2nd work coil L₁, L₂Are both turned on to the "muramura process" and when the "muramura process" is completed, the second work coil L₂Only the “heat-retaining step” is ON, and the control is finished.
[0040]
  (Power adjustment control of the first and second work coils during single drive and simultaneous drive)
  Next, FIG. 5 shows, for example, the first work coil L in the above-described temperature raising step or the like.₁2nd work coil L at the time of single drive only or in the heat insulation process₂1st and 2nd work coil L at the time of single drive only and in a water absorption process, a boiling maintenance process, an unevenness process, etc.₁, L₂Each power adjustment control method during simultaneous driving is shown.
[0041]
  In the control, first, the rice cooking switch or the heat retention selection switch is turned ON, and the first and second work coils L are operated.₁, L₂Start on condition that either or both of them are operating.
[0042]
  And first, step S₁The process is a temperature raising process, and the first work coil L₁It is determined whether only one is operating alone, and if YES, step S₂The actual work power is determined by detecting the current on the primary side of the power supply circuit by the power detection means comprising the current transformer 11 and the current detection circuit 12 described above, and the first work coil L₁Is operating according to a predetermined target power value. As a result, when the result is NO, it is further determined whether the actual operating power value is higher than the predetermined target power value or lower than the target power value. ) Includes step S_FourTo 1st work coil L₁Drive pulse width (n in FIG.₁) To increase the duty ratio, while if it is high (YES), step S_FiveThen, the width of the drive pulse is reduced to reduce the duty ratio.
[0043]
  Then, by each of them, the first work coil L so that the power value actually detected and determined converges to the predetermined target power value.₁Is adjusted appropriately.
[0044]
  On the other hand, the above step S₁In the first work coil L₁When NO is not operating or step S₂If the actual detected power value of YES is the predetermined power value as the target power value, then step S₆For example, the process is the heat retaining process described above, and the second work coil L₂It is determined whether or not only the case is operating alone.
[0045]
  As a result, if YES, step S₇To the second work coil L₂Is operating at a power value according to a predetermined target power value. If the result is NO, step S is further performed.₈Thus, it is determined whether the actual operating power value is higher than the predetermined target power value or lower than the target power value. If the actual operating power value is lower than the target power value (NO), step S is performed.₉To 2nd work coil L₂Drive pulse width (n in FIG. 6B)₂) To increase the duty ratio, while if it is high (YES), step S_TenThen, the width of the drive pulse is reduced to reduce the duty ratio.
[0046]
  Then, the second work coil L so that the power value actually detected and determined by each of them converges to the predetermined target power value.₂Is adjusted appropriately.
[0047]
  On the other hand, the above step S₆In the second work coil L₂When NO is not operating or step S₇Second work coil L with YES₂If the actual detected power value is a predetermined power as the target power value, then step S₁₁For example, the process includes the above-described water absorption process, boiling maintenance process, unevenness process, etc., and the first and second work coils L₁, L₂It is determined whether or not both are operating simultaneously.
[0048]
  As a result, if YES, step S₁₂To the first and second work coils L in the same manner as described above.₁, L₂By detecting and determining the total power value, it is determined whether or not it is operating according to a predetermined target power. If the result is NO, step S is further performed.₁₃It is determined whether or not the actual operating power value determined in the same manner is higher than the predetermined target power value or lower than the target power value, and if it is low (NO) according to the determination result, step S₁₄To 1st and 2nd work coil L₁, L₂The width of each drive pulse (n in FIG. 6A)₁, N in FIG. 6 (b)₂) To increase the duty ratio, while if it is high (YES), step S₁₅To the first and second work coils L₁, L₂The duty ratio is reduced by reducing the width of each drive pulse.
[0049]
  The first and second work coils L that are actually detected by each of them as described above.₁, L₂The first work coil L and the second work coil L so that the power value converges to the predetermined target power value₁, L₂Is adjusted appropriately.
[0050]
  As described above, the present invention provides a plurality of work coils for heating a rice cooker, a power supply circuit for driving a work coil, and a plurality of works for driving the plurality of work coils with predetermined power via the power supply circuit. In an electric rice cooker comprising a coil drive circuit and a work coil drive control means for driving or controlling the plurality of work coils individually or simultaneously through the work coil drive circuits, a primary side of the power supply circuit is provided. Current detection means for detecting a current value is provided, and each heating power of each of the plurality of work coils is controlled using a single feedback circuit based on the current value detected by the current detection means. It is a feature.
[0051]
  According to such a configuration, only one system is sufficient for both the power detection circuit and the power feedback circuit, the circuit configuration is simple, and the cost of the apparatus can be reduced.
[0052]
  In the present invention, in the above configuration, the heating control process for controlling the output is a heating control process in which a plurality of work coils are first driven individually.
[0053]
  As for the output control of the work coil by the single power detection circuit and the single power feedback circuit, the heating control process for controlling the output is appropriately performed in the heating control process in which a plurality of work coils are individually driven. Executed.
[0054]
  The present invention is characterized in that, in the above configuration, the heating control step for controlling the output is a heating control step in which a plurality of work coils are simultaneously driven.
[0055]
  The work coil output control by the single power detection circuit and the single power feedback circuit is appropriately executed even in the heating control process in which a plurality of work coils are driven simultaneously. Is done.
[0056]
  (Embodiment 2)
  Next, the flowchart of FIG. 7 and the time chart of FIG. 8 relate to the power adjustment control method during the single drive and the simultaneous drive of the first and second work coils of the electric rice cooker according to the second embodiment of the present invention. Show.
[0057]
  In the control, first, as in the case of the flowchart of FIG. 5, the above-mentioned rice cooking switch or the heat retention selection switch is turned ON, and the above-described first and second work coils L are operated.₁, L₂Start on condition that either or both of them are operating.
[0058]
  And first, step S₁Then, the first work coil L₁It is determined whether only one is operating alone, and if YES, step S₂Then, it is determined whether or not the operation state is operating according to a predetermined target power value by detecting the power with the power detection means including the current transformer 11 and the current detection circuit 12. As a result, when the result is NO, it is further determined whether the actual operating power value is higher than the predetermined target power value or lower than the target power value. ) Includes step S_FourTo the first work coil L₁Drive pulse width (n in FIG.₁) To increase the duty ratio, while if it is high (YES), step S_FiveThen, the width of the drive pulse is reduced to reduce the duty ratio. Then, by each of them, the first work coil L so that the actually detected power value converges to the predetermined target power value.₁Is adjusted appropriately.
[0059]
  On the other hand, the above step S₁In the first work coil L₁When NO is not operating or step S₂If the actual detected power value of YES is the predetermined power value as the target power value, then step S₆For example, the process is the heat retaining process described above, and the second work coil L₂It is determined whether or not only the case is operating alone.
[0060]
  As a result, if YES, step S₇And the actual power value is detected as described above, and the second work coil L₂It is determined whether or not is operating with power according to a predetermined target power value. If the result is NO, step S is further performed.₈Thus, it is determined whether the actual operating power value is higher than the predetermined target power value or lower than the target power value. If the actual operating power value is low (NO) according to the determination result, step S₉To the second work coil L₂Drive pulse width (n in FIG. 6B)₂) To increase the duty ratio, while if it is high (YES), step S_TenThen, the width of the drive pulse is reduced to reduce the duty ratio.
[0061]
  Then, by each of them, the second work coil L so that the actually detected power value converges to the predetermined target power value.₂Is adjusted appropriately.
[0062]
  On the other hand, the above step S₆In the second work coil L₂When NO is not operating or step S₇Second work coil L with YES₂If the actual detected power value is a predetermined power value as the target power value, then step S₁₁For example, the process includes the above-described water absorption process, boiling maintenance process, unevenness process, etc., and the first and second work coils L₁, L₂It is determined whether or not both are operating simultaneously.
[0063]
  As a result, if YES, step S₁₂To the first and second work coils L.₁, L₂Is operating according to a predetermined target power value. If the result is NO, step S is further performed.₁₃The first and second work coils L₁, L₂It is determined whether the total actual operating power value is higher than the predetermined target power value or lower than the target power value. If the total actual operating power value is lower than the target power value, if it is low (NO), step S₁₄To the first and second work coils L₁, L₂While increasing the total output value (wattage), if it is high (YES), step S₁₅To the first and second work coils L₁, L₂Reduce the total output value.
[0064]
  In this case, for example, as shown in FIG.₁The maximum output is 1400W and the second work coil L₂The output power of the second work coil L is set to be larger than the output 200 W of the second work coil L.₂The first work coil L with a large output is fixed at 200W₁The output 1400W is configured to be varied by changing it in the range of 1200 to 1400W.
[0065]
  Then, by each of them, the first and second work coils L so that the actually detected power value converges to the predetermined target power value.₁, L₂Is adjusted appropriately.
[0066]
  As described above, in the present invention, the plurality of work coils are composed of two sets of work coils, that is, a first work coil having a large output and a second work coil having a smaller output than the first work coil. The heating output is controlled by fixing the output of any one of the work coils to a predetermined output value and varying the output value of the other work coil.
[0067]
  The output control of the work coil by the single power detection circuit and the single power feedback circuit similar to those in the first embodiment is performed when the plurality of work coils are driven at the same time. The first work coil having a large output and the second work coil having a smaller output than the first work coil. The heating output is controlled by fixing the output of one of the work coils to a predetermined output value. Even in the case of changing the output value of the other work coil, the same can be applied.
[0068]
  In such a case, the output of the first work coil is larger than the output of the second work coil, and the control of the heating output is performed by fixing the output of the second work coil having a small output. The first work coil having a larger output is configured to be varied by changing the output.
[0069]
  When the work coil is employed as a heating means, it does not function effectively as an electromagnetic induction heating means unless there is an output of a predetermined size at a minimum.
[0070]
  Therefore, when the first and second sets of work coils are driven simultaneously, the adjustment control of the heating output is performed by first adjusting the output of the second work coil having a smaller output to a predetermined required magnitude. It is preferable to adjust by changing the output of the first work coil having a larger output.
[0071]
  In that case, in the same configuration, the second work coil is characterized in that the heating amount is adjusted only by time-division control, and the output of the second work coil having a small output is obtained. When it is constant, the heating amount of the second work coil is appropriately adjusted only by time-sharing control.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view showing a configuration of an entire rice cooker body portion of an electric rice cooker according to an embodiment of the present invention.
FIG. 2 is an electric circuit diagram of a feedback control circuit portion for driving power of first and second work coils, which is a main part of the electric rice cooker.
FIG. 3 is a flowchart showing a basic control operation during normal rice cooking of the electric rice cooker.
FIG. 4 is a time chart showing a control pattern of heating temperature in the rice cooking to heat retaining process of the electric rice cooker.
FIG. 5 is a flowchart showing a power adjustment control method for the first and second work coils in a heating to heat holding process of the electric rice cooker.
FIG. 6 is a time chart showing ON / OFF patterns of the first and second work coils in the rice cooking to heat insulation heating process of the electric rice cooker.
FIG. 7 is a flowchart showing a power adjustment control method for first and second work coils in a rice cooking to heat insulation heating process of an electric rice cooker according to Embodiment 2 of the present invention.
FIG. 8 is a time chart showing ON and OFF patterns of the first and second work coils in the rice cooking to heat insulation heating process of the electric rice cooker.
[Explanation of symbols]
  1 is a rice cooker body, 2 is a rice cooker, 3 is a lid unit, 4 is an inner case, 5 is an outer case, 10 is a microcomputer control unit, 11 is a current transformer, 12 is a power detection circuit, and 21 is a first IGBT drive Circuit, 22 is a second IGBT drive circuit, 23 is a first IGBT, 24 is a second IGBT, C₁Is the first resonant capacitor, C₂Is the second resonant capacitor, L₁Is the first work coil, L₂Is a second work coil.

Claims (3)

A plurality of work coils for heating the rice cooker, a power supply circuit, a plurality of work coil drive circuits for driving the plurality of work coils with a predetermined power via the power supply circuit, and the plurality of work coils for each work. An electric rice cooker comprising drive control means for controlling drive individually or simultaneously via a coil drive circuit, provided with current detection means for detecting a current value on the primary side of the power supply circuit, and detected by the current detection means The heating control step of controlling each heating power of each of the plurality of work coils using a single feedback circuit based on the current value and controlling the output is a heating in which the plurality of work coils are driven simultaneously. It is a control step, and the plurality of work coils are composed of a first work coil and a second work coil, and the control of the heating output is the output of one of the work coils. Fixed to a predetermined output value, electric rice cookers, characterized in that the output value of the other side work coil adapted to be made by varying. The output of the first work coil is larger than the output of the second work coil, and the control of the heating output is performed by fixing the output of the second work coil having a small output and the output of the first work coil having a large output. The electric rice cooker according to claim 1 , wherein the electric rice cooker is configured so as to be varied. The electric rice cooker according to claim 2 , wherein the heating amount of the second work coil is adjusted only by time division control.

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