KR102238458B1 - Heating device and power control method - Google Patents

Abstract

The present disclosure discloses a heating device. A heating apparatus according to the technical idea of the present disclosure includes a plurality of heating elements including a first heating element as a resistance heating heating element and a second heating element as an induction heating heating element, and a control unit for controlling the output of each of the plurality of heating elements, The control unit calculates the total power consumed when the plurality of heating elements drive a positive output according to the user's set output, controls the first heating element to be driven to a positive output when the total power consumption exceeds the available power, and the second heating element Is controlled to drive a limiting output having a level lower than the positive output.

Description

Heating device and power control method thereof {HEATING DEVICE AND POWER CONTROL METHOD}

The technical idea of the present disclosure relates to a heating device and a power control method of the heating device, and more particularly, to a heating device for efficiently controlling power of a plurality of heating elements, and a power control method thereof.

Various types of heating devices are used in homes or restaurants for various purposes including cooking or sterilization. Recently, heating devices for heating an object to be heated such as a pot, a frying pan, a steamer, or a kettle using electricity have been widely spread.

The heating method using electricity largely includes a resistance heating method and an induction heating method. The resistance heating method is a method of heating an object by directly transferring heat generated when an electric current is passed through a metal resistance wire or a non-metallic heating element such as silicon carbide through radiation or conduction to heat an object, and is used for highlights. On the other hand, the induction heating method is used for induction by generating an induction current in an object to be heated by using a change in a magnetic field generated around the coil when high frequency power is applied to the coil, so that the object to be heated is heated.

In such a heating method using electricity, when power is continuously supplied to a plurality of heating elements, the power consumption exceeds the allowable value and the circuit breaker may be blocked, and an electric accident such as a fire may occur due to heat generation. Accordingly, a number of heating elements constituting the heating device operate at the same time, and various measures have been derived to prevent electrical safety accidents that may occur when power consumption exceeds a permissible value.

A problem to be solved by the technical idea of the present disclosure is to provide a heating device capable of controlling the power of the heating elements so as to prevent safety accidents due to an increase in the amount of heat generated by the heating elements when a plurality of heating elements operate simultaneously.

In order to achieve the above object, the heating device according to the technical idea of the present disclosure includes a plurality of heating elements including a first heating element as a resistance heating heating element and a second heating element as an induction heating heating element, and outputs of each of the plurality of heating elements. Includes a control unit to control, and the control unit calculates the total power consumption when the plurality of heating elements are driven to a positive output according to the user's set output, and outputs the first heating element positively when the total power consumption exceeds the available power. It can be controlled to drive and control the second heating element to drive a limited output having a level lower than the positive output.

In an embodiment, the plurality of heating elements includes a third heating element that is an induction heating heating element, and the controller may control the third heating element to be driven with a limited output when the total power consumption exceeds the available power.

In an embodiment, a section in which the second heating element drives the limit output and the section in which the third heating element drives the limit output may overlap with each other.

In an embodiment, the level of the limiting output of the second heating element may be the same as the limiting output level of the third heating element.

In one embodiment, the control unit recalculates the total power consumed when the second heating element drives the limited output and the heating elements other than the second heating element drive the constant output, and the recalculated total power consumption exceeds the available power. At this time, it is possible to drive the third heating element with limited output.

In an embodiment, the level of the limiting output of the second heating element may have a constant value.

In one embodiment, the control unit recalculates the total power consumed when the plurality of heating elements are driving positive output while the second heating element is driving the limit output, and when the recalculated total power consumption is less than the available power, the second heating element is The heating element can be controlled to drive a constant output.

The heating device according to the technical idea of the present disclosure may satisfy an allowable value of power consumption through power control of each of the heating elements. Therefore, it is possible to prevent a safety accident due to an increase in the amount of heat generated by the heating element.

1 is a perspective view showing a heating device according to an exemplary embodiment of the present disclosure.
FIG. 2 is a block diagram showing the configuration of the heating device shown in FIG. 1.
3 is a flowchart illustrating a method of controlling power of a heating device according to an exemplary embodiment of the present disclosure.
4A and 4B are timing diagrams for explaining a power control method of the heating device of FIG. 3.
5A and 5B are timing diagrams for explaining a power control method of the heating device of FIG. 3.

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the embodiments of the present disclosure may be modified in various forms, and the scope of the present disclosure should not be construed as being limited by the embodiments described below. It is preferable that the embodiments of the present disclosure be interpreted as being provided in order to more fully describe the present disclosure to those having average knowledge in the art. Identical symbols mean the same elements all the time. Furthermore, various elements and areas in the drawings are schematically drawn. Accordingly, the inventive concept is not limited by the relative size or spacing drawn in the accompanying drawings.

Unless otherwise defined, all terms used herein, including technical terms and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concept belongs. In addition, terms commonly used, as defined in the dictionary, should be construed as having a meaning consistent with what they mean in the context of the technology to which they are related, and in an excessively formal sense unless explicitly defined herein. It will be understood that it should not be interpreted.

1 is a perspective view showing a heating device according to an exemplary embodiment of the present disclosure. FIG. 2 is a block diagram showing the configuration of the heating device shown in FIG. 1.

1 and 2, the heating device 1 may include a plate-shaped body 2. The upper part of the body 2 is provided on one side of the plurality of heating elements 10_1 to 10_3 and the heating elements 10_1 to 10_3 to receive user input and display status information of the plurality of heating elements 10_1 to 10_3. The user interface 40 may be arranged. When operating the plurality of heating elements 10_1 to 10_3, the heating device 1 may control power of each of the plurality of heating elements 10_1 to 10_3 by supplying power so as not to exceed an allowable value of power consumption. For example, the heating device 1 may be an electric range that uses electricity as an energy source to heat an object to be heated through a plurality of heating elements 10_1 to 10_3 corresponding to a crater.

The heating device 1 provides power to the plurality of heating elements 10_1 to 10_3 to drive the plurality of heating elements 10_1 to 10_3, a plurality of driving units 20_1 to 20_3, and a plurality of heating elements 10_1 to 10_3. ), and a control unit 50 for controlling overall operations of the heating device 1. In one embodiment, the heating device 1 may include three heating elements, that is, a first heating element 10_1, a second heating element 10_2, and a third heating element 10_3, and the first heating element 10_1 And a first driving unit 20_1 for supplying power to the second heating element 10_2, a second driving unit 20_2 for supplying electric power to the second heating element 10_2, and a third driving unit 20_3 for supplying electric power to the third heating element 10_3. I can. However, the present disclosure is not limited thereto, and the number of heating elements included in the heating device 1 may be variously configured. That is, the heating device 1 may include two heating elements, or may include four or more heating elements.

In one embodiment, the heating device 1 may include heating elements having different heating methods. For example, the first heating element 10_1 may be a highlight using a resistance heating method, and the second heating element 10_2 and the third heating element 10_3 may be induction using an induction heating method. For example, the output of the first heating element 10_1 may be adjusted in multiple stages according to the on-section output at a certain period. The first heating element 10_1 may generate a lower level of output as the on-section is shorter, and a higher level of output as the on-section is longer.

At least one of the plurality of heating elements 10_1 to 10_3 may have a maximum output different from that of other heating elements. For example, the maximum output of the first heating element 10_1 and the maximum output of the second heating element 10_2 are the same, but the maximum output of the third heating element 10_3 may be different from the maximum output of the first heating element 10_1. . Alternatively, for example, the maximum output of the first heating element 10_1, the maximum output of the second heating element 10_2, and the maximum output of the third heating element 10_3 may be different from each other. However, the present disclosure is not limited thereto, and the maximum outputs of the plurality of heating elements 10_1 to 10_3 may all be the same.

The power supply unit 30 may provide power to each of the plurality of driving units 20_1 to 20_3 from an external power source. Each of the plurality of driving units 20_1 to 20_3 may drive a corresponding heating element in response to the control of the controller 50, and may adjust the output of the corresponding heating element using power provided from the power supply unit 30. For example, the first driving unit 20_1 may adjust the output of the first heating element 10_1 in response to the control of the control unit 50, and the second driving unit 20_2 2 The output of the heating element 10_2 can be adjusted, and the third driving unit 20_3 can adjust the output of the third heating element 10_3 in response to the control of the control unit 50.

The user interface 40 may include a manipulation unit that receives a user's command and a display unit that displays information related to an operation state of each of the plurality of heating elements 10_1 to 10_3. That is, the user interface 40 provides a command corresponding to a user's manipulation, for example, selecting a plurality of heating elements 10_1 to 10_3 to be driven, or an on/off operation of the selected heating element, adjustment of driving time, and output adjustment. It can be generated and output to the control unit 50. In addition, the user interface 40 may display an operating state of the heating device 1, such as on/off of the heating element, an output stage, a driving time, and a temperature, under the control of the controller 50.

The controller 50 may control the output of each of the plurality of heating elements 10_1 to 10_3 by controlling each of the plurality of driving units 20_1 to 20_3. The controller 50 may control an output of each of the plurality of heating elements 10_1 to 10_3 based on a user's setting received through the user interface 40. In one embodiment, when at least two of the plurality of heating elements 10_1 to 10_3 are operated, the control unit 50 includes a plurality of heating elements 10_1 to 10_3 so as not to exceed the allowable power consumption, that is, the available power. Each output can be controlled. An operation in which the controller 50 controls the total power consumption of the plurality of heating elements 10_1 to 10_3 will be described in detail later in FIGS. 3 to 5B.

In the heating apparatus 1 according to the present disclosure, when the total power consumption is predicted to exceed the available power when the plurality of heating elements 10_1 to 10_3 are driven according to the setting of the consumer, the plurality of heating elements 10_1 to 10_3 You can limit the output of some of them. The heating device 1 can prevent the total power consumption from exceeding the available power by controlling the output of each of the plurality of heating elements 10_1 to 10_3 when the plurality of heating elements 10_1 to 10_3 are simultaneously driven. .

3 is a flowchart illustrating a method of controlling power of a heating device according to an exemplary embodiment of the present disclosure.

2 and 3, in step S10, the controller 50 may receive a user's setting command for the plurality of heating elements 10_1 to 10_3 through the user interface 40. For example, the controller 50 may receive a command to change the output of at least one of the plurality of heating elements 10_1 to 10_3. For example, the controller 50 may receive a command for changing at least one of the plurality of heating elements 10_1 to 10_3 from an off state to an on state having a user's setting output. That is, the user's setting output may be an output set by the user through the user interface 40.

In step S20, the controller 50 may calculate the total power consumption of the plurality of heating elements 10_1 to 10_3 based on a user's setting command. That is, when the plurality of heating elements 10_1 to 10_3 are driven according to the setting output set by the user, the controller 50 may pre-calculate the total power consumption of the plurality of heating elements 10_1 to 10_3. For example, the control unit 50 has a first power consumption when driving the first heating element 10_1 to have a user's set output, and a second power consumption when driving the second heating element 10_2 to have a user's set output. The estimated total power consumption of the plurality of heating elements 10_1 to 10_3 may be calculated by summing the power consumption and the third power consumption when the third heating element 10_3 is driven to have a user's set output.

In step S30, the controller 50 may determine whether the total power consumption of the plurality of heating elements 10_1 to 10_3 calculated in step S20 exceeds the available power. In an embodiment, the available power may be a preset value, and may be a reference value for preventing an electric accident from occurring. In an embodiment, when three or more of the plurality of heating elements 10_1 to 10_3 are simultaneously driven to have an output set by the user, the total power consumption may exceed the available power.

When the calculated total power consumption of the plurality of heating elements 10_1 to 10_3 does not exceed the available power, in step S40, the control unit 50 controls each of the plurality of heating elements 10_1 to 10_3 to drive a positive output. I can. In this case, the positive output driving may mean driving to have an output according to a user's set output.

When the calculated total power consumption of the plurality of heating elements 10_1 to 10_3 exceeds the available power, in step S50, the control unit 50 generates an induction heating element, that is, an induction heating element among the plurality of heating elements 10_1 to 10_3. It can be controlled to drive limited output. In this case, the limited output driving may mean driving with an output lower than the user's set output. By limiting driving of at least one of the plurality of heating elements 10_1 to 10_3, the total power consumption of the plurality of heating elements 10_1 to 10_3 may be prevented from exceeding the available power.

For example, when the user attempts to drive the third heating element 10_3 while the first heating element 10_1 and the second heating element 10_2 are being driven, the control unit 50 outputs the highlight of the first heating element 10_1 to the user. It is possible to reduce the output of the second heating element 10_2 while maintaining it as the set output of. Or, for example, when the user intends to drive the first heating element 10_1 while the second heating element 10_2 and the third heating element 10_3 are driving, the control unit 50 includes the second heating element 10_2 and the third heating element The output of (10_3) can be reduced. The limiting output driving control operation of the controller 50 will be described later in FIGS. 4A to 5B.

After performing step S50, the control unit 50 may perform steps S10 to S30 again. For example, when a user's setting command for at least one of the first heating element 10_1, the second heating element 10_2, and the third heating element 10_3 is newly received through the user interface 40, the newly received setting command The total power consumption of the plurality of heating elements 10_1 to 10_3 may be calculated based on and it may be determined whether the calculated total power consumption exceeds the available power.

4A and 4B are timing diagrams for explaining a power control method of the heating device of FIG. 3. 4A and 4B illustrate a case where the first heating element is a highlight, and the second heating element and the third heating element are induction, but the heating device according to the present disclosure is not limited thereto, and a heating device including a highlight and induction is provided. The following description may be applied. 4A and 4B exemplarily illustrate a method of controlling power of a heating device when an output of induction is changed while a highlight is driven to a positive output.

Referring to FIG. 4A, the first heating element may repeatedly have an on-section (P_on) outputted as a constant first positive output (Wa) and an off-section (P_off) not outputted within a predetermined period (P). . When the user increases the set output of the first heating element, the controller may control the on-period P_on output in the period P to lengthen while maintaining the level of the first positive output Wa. On the other hand, when the user lowers the set output of the first heating element, the control unit maintains the level of the first positive output Wa, the on-section P_on output within the period P is shortened, and the off-section ( P_off) can be controlled to lengthen.

When the user increases the set output of the second heating element and/or the third heating element, the control unit controls the level of the output of the second heating element and/or the third heating element, unlike the first heating element that adjusts the duty ratio within a certain period (P). By increasing the output of the second heating element and/or the third heating element may be increased. That is, the output level of the second positive output Wb of the second heating element and the third positive output Wc of the third heating element corresponding to the user's set output may be increased or the output level may be increased according to the user’s set output. Can be lowered.

In one embodiment, when the total power consumption of the plurality of heating elements calculated based on the user's setting command exceeds the available power, the control unit outputs the limit output (Wbl) to the second heating element that was driven by the second positive output (Wb). It can be controlled to drive by. The limit output Wbl may have a level lower than the second positive output Wb corresponding to the user's set output. In an embodiment, the level of the limit output Wbl may be a preset value. In an embodiment, the level of the limit output Wbl may be a constant value regardless of the level of the second positive output Wb. For example, when the second positive output Wb is 1.4 kW, the second heating element may be controlled to be driven with a limited output Wbl of 1.0 kW, and even when the second positive output Wb is 2.0 kW, the second heating element The heating element may be controlled to drive with a limited output Wbl of 1.0kW.

For example, while the first heating element and the second heating element are driven at the first positive output (Wa) and the second positive output (Wb), respectively, the user increases the output of the third heating element (e.g., turned on from the off state). State), and the controller may receive a user's setting command corresponding thereto. At this time, when the first heating element, the second heating element, and the third heating element are simultaneously driven at the first positive output (Wa), the second positive output (Wb) and the third positive output (Wc), respectively, the total power consumption (Wa) +Wb+Wc) may exceed the available power. The control unit drives the third heating element to a third positive output Wc at a first point in time t_1, and limits output Wbl to the second heating element at a fast limit point tb_1 or coincides with the first point t_1. It can be controlled by driving.

Specifically, for example, when the first positive output (Wa) is 1.4kW, the second positive output (Wb) is 1.4kW, and the third positive output (Wc) is 1.4kW, the control unit is the first positive output (Wa) , By summing all of the second positive output Wb and the third positive output Wc, the total power consumption of the plurality of heating elements may be calculated as a total of 3.8 kW. When the available power is 3.4kW, the calculated total power consumption exceeds the available power, so the control unit limits the second heating element from the time limit (tb_1) to the second heating element that was being driven with the second positive output (Wb) (Wbl). It can be controlled by driving.

The first heating element and the third heating element are driven by a first positive output (Wa) and a third positive output (Wc), respectively, and the second heating element is driven by a limited output (Wbl), while the user is at least one heating element, a third heating element. The output of may be reduced (eg, turned off), and the controller may receive a user's setting command corresponding thereto. In this case, when the first heating element and the second heating element are driven simultaneously with the first positive output Wa and the second positive output Wb, respectively, the total power consumption Wa+Wb may be less than or equal to the available power. The control unit may lower the level of the third positive output Wc of the third heating element at the second time point t_2 (for example, turn it off), and coincide with the second time point t_2 or at a late recovery time (tb_rec). ), the second heating element can be driven and controlled again with a positive output Wb. Each of the first time point t_1 and the second time point t_2 may be a time point at which the entire output is changed according to the user's setting, and each of the limit time point tb_1 and the recovery time point tb_rec is controlled by the power control of the controller itself. It may be a time point at which the entire output is changed.

Referring to FIGS. 4A and 4B, the control unit may control a heating element whose output is changed by a user, for example, a third heating element, with limited output. In FIG. 4B, both the second heating element and the third heating element are controlled with limited output, but the present disclosure is not limited thereto, and only the third heating element, which is a heating element whose output is changed by the user, may be controlled with the limited output.

When the total power consumption of the plurality of heating elements calculated based on the user's setting command exceeds the available power, the control unit outputs a limit output (Wcl) from the first time point t_1 to the second time point t_2 It can be controlled to drive by. In one embodiment, the control unit drives the third heating element to the limited output (Wcl) when the total power consumption of the plurality of heating elements is expected to exceed the available power even when the second heating element is driven with the limited output (Wbl). Can be controlled.

The limit output Wcl may have a lower level than the third positive output Wc corresponding to the user's set output. In an embodiment, the level of the limit output Wcl may be a preset value. In an embodiment, the level of the limit output Wcl may be a constant value regardless of the level of the third positive output Wc. For example, when the third positive output (Wc) is 1.4kW, the third heating element may be controlled to be driven with a limited output (Wcl) of 1.0kW, and even when the third positive output (Wc) is 1.3kW, the third heating element The heating element may be controlled to drive with a limited output (Wcl) of 1.0 kW.

In an embodiment, the level of the limiting output Wcl of the third heating element may be the same as the level of the limiting output Wbl of the second heating element. However, the present disclosure is not limited thereto, and the level of the limiting output Wcl of the third heating element may be different from the level of the limiting output Wbl of the second heating element.

For example, while the first heating element and the second heating element are driven at the first positive output (Wa) and the second positive output (Wb), respectively, the user can drive (ON) the third heating element that has been turned off. have. At this time, when the first heating element, the second heating element, and the third heating element are simultaneously driven at the first positive output (Wa), the second positive output (Wb) and the third positive output (Wc), respectively, the total power consumption (Wa) +Wb+Wc) may exceed the available power. Specifically, for example, when the first positive output (Wa) is 1.4kW, the second positive output (Wb) is 1.4kW, and the third positive output (Wc) is 1.4kW, the control unit is the first positive output (Wa) , By summing all of the second positive output Wb and the third positive output Wc, the total power consumption of the plurality of heating elements may be calculated as a total of 3.8 kW. When the available power is 3.4kW, the calculated total power consumption exceeds the available power, so the control unit outputs a limit output (Wcl, for example, 1.0kW) from the first time point (t_1) to the third heating element whose set output is changed. It can be controlled to drive by.

The heating apparatus according to the present disclosure can predict in advance whether or not the available power will be exceeded when a plurality of heating elements operate simultaneously. The heating device may selectively control at least one of the second heating elements and the third heating elements, which are inductions excluding the highlight, to have limited outputs Wbl and Wcl having a level lower than the positive output Wb or Wc. Thus, the heating device can prevent exceeding the allowable value of the power consumption and can prevent the heating efficiency from being excessively reduced.

5A and 5B are timing diagrams for explaining a power control method of the heating device of FIG. 3. 5A and 5B illustrate a case where the first heating element is a highlight, and the second heating element and the third heating element are induction, but the heating device according to the present disclosure is not limited thereto, and a heating device including a highlight and induction is provided. The following description may be applied. 5A and 5B exemplarily illustrate a method of controlling power of a heating device when an output of a highlight is changed while induction is driven to a positive output.

Referring to FIG. 5A, when the total power consumption of the plurality of heating elements calculated as the output of the highlight first heating element is changed exceeds the available power, the controller is the second heating element driven with the second positive output Wb, One of the third heating elements driven by the third positive output Wc may be controlled to drive the limited output Wbl or Wcl. The limited output Wbl or Wcl may have a level lower than the second positive output Wb corresponding to the user's set output.

For example, while the second heating element and the third heating element are driven at the second positive output (Wb) and the third positive output (Wc), respectively, the user increases the output of the first heating element (for example, driving in the off state (Change to the ON state), and the controller may receive a user's setting command corresponding thereto. At this time, when the first heating element, the second heating element, and the third heating element are simultaneously driven at the first positive output (Wa), the second positive output (Wb) and the third positive output (Wc), respectively, the total power consumption (Wa) +Wb+Wc) may exceed the available power. The control unit drives the first heating element to a first positive output Wa at a first point in time t_1', and outputs a limit on the second heating element at a fast limit point tb_1 or coincides with the first point in time t_1'. Wbl) can be controlled.

The first heating element and the third heating element are driven by a first positive output (Wa) and a third positive output (Wc), respectively, and the second heating element is driven by a limited output (Wbl), while the user is at least one heating element, a third heating element. The output of may be reduced (eg, turned off), and the controller may receive a user's setting command corresponding thereto. In this case, when the first heating element and the second heating element are driven simultaneously with the first positive output Wa and the second positive output Wb, respectively, the total power consumption Wa+Wb may be less than or equal to the available power. The control unit may reduce the size of the third positive output Wc of the third heating element at the second point in time t_2' (for example, turn it off), and the second point in time t_2' coincides with or is a late recovery point. In (tb_rec), the second heating element may be controlled to be driven again with a positive output Wb.

5A and 5B, when the total power consumption of the plurality of heating elements calculated as the output of the highlight first heating element is changed exceeds the available power, the control unit operates with the second positive output Wb. The second heating element and the third heating element driven by the third positive output Wc can be controlled to drive the limit outputs Wbl and Wcl, respectively. In one embodiment, the control unit drives the third heating element to the limited output (Wcl) when the total power consumption of the plurality of heating elements is expected to exceed the available power even when the second heating element is driven with the limited output (Wbl). Can be controlled.

When the calculated total power consumption of the plurality of heating elements exceeds the available power, the control unit may drive and control the second heating element from the limiting point (tb_1) to the recovery point (tb_rec) with the limiting output (Wbl), and the third heating element From the limit time point tc_1 to the second time point t_2', the limit output Wcl may be controlled. A section in which the second heating element is driven with the limiting output Wbl and a section in which the third heating element is driven with the limiting output Wcl may overlap each other, and, for example, may coincide with each other.

The heating device according to the present disclosure selectively controls at least one of the second heating elements and the third heating elements, which are inductions excluding the highlight, to have a limiting output (Wbl, Wcl) having a level lower than the positive output (Wb or Wb). I can. While the highlight controls the output by adjusting the duty ratio, the induction controls the output by reducing the level of power itself, so it is easy to control the total power consumption so that the limiting output control of the induction does not exceed the allowable value. Accordingly, the heating device can effectively prevent exceeding the allowable value of the power consumption and can prevent the heating efficiency from being excessively reduced.

The technical idea of the present disclosure described above is not limited to the above-described embodiment and the accompanying drawings. In addition, it will be apparent to those of ordinary skill in the art that various substitutions, modifications, and changes are possible within the scope of the technical spirit of the present disclosure.

1: heating device
10_1~10_3: a plurality of heating elements
20_1~20_3: a plurality of driving units
30: power supply
40: user interface
50: control unit

Claims (7)

A plurality of heating elements including a first heating element as a resistance heating heating element, and including a second heating element and a third heating element as an induction heating element; And
Including a control unit for controlling the power of each of the plurality of heating elements,
The control unit,
When each of the plurality of heating elements drives a positive output according to a user's setting, the total power consumption is calculated, and when the total power consumption exceeds the available power, the second and third heating elements, which are induction heating heating elements, are Controlling the second heating element to drive a limiting output having a level lower than the positive output of the second heating element of the heating element at which the driving start point is early, The first heating element, which is a resistance heating heating element, is controlled to drive a positive output by maintaining a ratio between an on-section in an on state and an off-section in an off state so as to correspond to a user setting,
The control unit,
When the second heating element is driven with a limited output and the heating elements other than the second heating element are driven with a positive output, the total power consumption is recalculated, and when the recalculated total power consumption exceeds the available power, the third Controlling the heating element to drive the limited output,
A heating device, characterized in that the section in which the second heating element drives the limit output and the section in which the third heating element drives the limit output overlap each other. delete delete The method of claim 1,
The heating device, characterized in that the level of the limiting output of the second heating element has the same value as the limiting output level of the third heating element. delete The method of claim 1,
Heating device, characterized in that the level of the limiting output of the second heating element has a constant value. The method of claim 1,
The control unit,
When the recalculated total power consumption is less than or equal to the available power, the third heating element is controlled to drive the positive output.

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