Planar heating device and planar heating system

Abstract

To provide a planar warmer that includes a PTC heater that is suppressed in inrush current.SOLUTION: A planar warmer includes: a heat generating part 110 constituted by a PTC heater; a power source connection part 120 for supplying a current to the heat generating part; a power source output part 130 for outputting the power supplied from the power source connection part to another planar warmer; and a control unit 140 for controlling output from the power source connection part to the power source output part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a planar heating device and a planar heating system. [Background technology]

[0002] Conventionally, PTC heaters make it difficult for current to flow as the temperature rises, so floor heating panels, which are heating devices that use PTC heaters such as those described in Patent Document 1, have been manufactured with a simple structure that can prevent abnormal heating. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 4-129021 Summary of the Invention [Problem to be solved by the invention]

[0004] However, due to its characteristics, heating devices using PTC heaters have a larger inrush current than other heating devices. Therefore, in a large-area heating device made of PTC heaters, the inrush current is proportional to the area, and when the power is turned on, an overcurrent flows in the circuit due to the inrush current according to the area, causing problems such as tripping the breaker.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a sheet-shaped heating device using a PTC heater that suppresses inrush current. [Means for solving the problem]

[0006] The present invention relates to a heating unit that is composed of a PTC heater, a power supply connection unit for supplying current to the heating unit, a power supply output unit that outputs the power supplied from the power supply connection unit to another planar heating device, and a control unit that controls the current supply from the power supply connection unit to the power supply output unit. a substantially rectangular base portion supporting the heat generating portion, the power output portions being provided on four sides of the base portion, electrically connected to the heat generating portion, and electrically connected to each other. It is characterized by: Effect of the Invention

[0007] According to the present invention, it is possible to provide a sheet-shaped heating device using a PTC heater that suppresses inrush current. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an exploded perspective view showing a schematic configuration of a planar heating device according to a first embodiment. [Diagram 2] FIG. 2 is a plan view and a cross-sectional view taken along line II' of the planar heating device. [Diagram 3] 1 is a graph showing the relationship between current consumption and temperature of a heat generating portion. [Figure 4] FIG. 2 is a functional diagram showing the internal structure and system configuration of the planar heating device. [Diagram 5] 4 is a flowchart showing the operation of the planar heating device. [Figure 6] 1 is a graph showing the relationship between current consumption and time of a sheet-shaped heating device system. [Figure 7] FIG. 11 is a perspective view showing a schematic configuration of a surface heating system according to a second embodiment. [Figure 8] FIG. [Figure 9] FIG. 2 is a perspective view showing a configuration of an upper case. [Figure 10] FIG. 4 is a bottom view showing the configuration of the upper case. [Figure 11] FIG. 2 is a diagram showing an example of the functional configuration of a planar heating device. [Figure 12] 1 is a graph for explaining a rise time. [Figure 13] 4 is a flowchart showing the operation of the planar heating device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The sheet-shaped heating device according to the present embodiment will be described below with reference to the drawings. For ease of explanation, in each drawing, the upper side is indicated as Up, the lower side as Lo, the right side as Ri, the left side as Le, the front side as Fr, and the rear side as Rr, as necessary.

[0010] (First embodiment) Fig. 1 is an exploded perspective view showing a schematic configuration of a planar heating device 100 according to a first embodiment. Fig. 2(a) is a plan view of the planar heating device 100. Fig. 2(b) is a cross-sectional view taken along line II' in Fig. 2(a), which is a plan view of the planar heating device 100. The planar heating device 100 of this embodiment is an electric carpet.

[0011] The sheet-shaped heating device 100 includes a heat generating section 110, a power connection section 120, a power output section 130, a control section 140, and an exterior section 150.

[0012] The heat generating unit 110 is a film heater that converts electric current into heat. The heat generating unit 110 is substantially rectangular when viewed from above. The heat generating unit 110 is disposed in the upper layer of the exterior unit 150, which is partitioned into two layers. The heat generating unit 110 is composed of a PTC film heater 111 and a heat insulating material 112.

[0013] The PTC film heater 111 converts electric current into heat. The PTC film heater 111 is substantially rectangular when viewed from above, and is, for example, a square with one side measuring 44 cm and a thickness of 1.0 cm or less. The PTC film heater 111 is placed on a heat insulating material 112 and is bonded to the heat insulating material 112 with an adhesive. The PTC film heater 111 is electrically connected to a power supply connection part 120.

[0014] FIG. 3 is a graph showing the relationship between the current consumption and the temperature of the heat generating part 110 of the sheet heating device 100. As shown in FIG. Among film heaters, the PTC film heater 111 has a PTC characteristic in which, as the temperature rises, the electrical resistance increases, making it difficult for current to flow, as shown in Fig. 3. Therefore, the current consumption is the largest when the temperature is the lowest. In other words, the inrush current, which is the current consumption when heat generation begins, is the largest. In addition, the amount of heat generated by the PTC film heater 111 gradually decreases in proportion to the current flowing as the temperature rises, and reaches a saturated state where the amount of heat generated and the amount of heat radiated to the outside air are approximately equal. In other words, the heat generated does not exceed a certain temperature, and the current consumption is constant. Although a film heater is used in this embodiment, other types of PTC heaters may be used, for example, fin-shaped or rod-shaped heaters.

[0015] The heat insulating material 112 adjusts the radiation direction of the heat generated by the PTC film heater 111 . The heat insulating material 112 has a substantially rectangular shape when viewed from above, similar to the heat generating portion 110. Also, the heat insulating material 112 is disposed below the PTC film heater 111, and is joined to the PTC film heater 111 with an adhesive.

[0016] The power connection part 120 supplies power from a power source to the sheet heating device 100. The power connection part 120 is composed of an attachment plug 121, a power cable 122, and a power supply part 123. The power connection part 120 is, for example, in the form of a cable having a length of 3.0 m.

[0017] The attachment plug 121 is a connector that is connected to a power source and supplies power to the sheet heating device 100. The attachment plug 121 is connected to a power cable 122. A conventionally known configuration can be applied to the attachment plug 121, and therefore detailed description thereof will be omitted.

[0018] The power cable 122 transmits electricity obtained from a power source to the sheet-shaped heating device 100. In Fig. 1 and Fig. 2(a), a part of the power cable 122 is illustrated by hidden lines. The power cable 122 is disposed between the attachment plug 121 and the power supply unit 123, and connects the respective components. Since a conventionally known configuration can be applied to the power cable 122, detailed description thereof will be omitted. Furthermore, the power cable 122 has flexibility such that it can bend at any portion.

[0019] The power supply unit 123 connects the power connection unit 120 , the heat generating unit 110 and the control unit 140 . 1 and 2(a), the power supply unit 123 is illustrated by hidden lines. The power supply unit 123 is connected to one of both ends of the power cable 122, the other end being opposite to the end to which the attachment plug 121 is connected. In this embodiment, the power supply unit 123 is integrally formed with the power output unit 130 and the control unit 140, but may be formed separately.

[0020] The power output unit 130 has a function of outputting power to other planar heating devices 100, etc. In Fig. 1 and Fig. 2(a), the power output unit 130 is illustrated by hidden lines. The power output unit 130 has a plug receptacle for connecting the attachment plug 121 of other planar heating devices 100, etc., and can be electrically connected. A conventionally known configuration that performs the above functions can be applied to the power output unit 130, and therefore detailed description thereof will be omitted. In this embodiment, the power output unit 130 is configured integrally with the power supply unit 123 and the control unit 140, but may be configured separately.

[0021] The control unit 140 controls the supply of electricity from the power connection unit 120 to the power output unit 130 . 1 and 2(a), the control unit 140 is illustrated by hidden lines. The control unit 140 has a delay unit 141 and a delay control unit 142. The control unit 140 is electrically connected to the power connection unit 120 and the power output unit 130. In this embodiment, the control unit 140 is configured integrally with the power supply unit 123 and the power output unit 130, but may be configured separately.

[0022] 4 is a functional diagram showing the internal structure and system configuration of the sheet heating device 100. The internal structure of the control unit 140 will be described with reference to FIG. The control unit 140 is electrically connected to the power supply connection unit 120 and the power supply output unit 130, and the sheet-shaped heating device 100 alone forms a closed circuit. For example, in FIG. 4, the sheet-shaped heating devices 100#1, #2, and #3 are different sheet-shaped heating devices 100, and each heating device forms a closed circuit. In the absence of the control unit 140 in the sheet-shaped heating device 100, the power supply connection unit 120 and the power supply output unit 130 are directly connected. In other words, when another sheet-shaped heating device 100 is connected, for example, when the sheet-shaped heating device 100#2 is connected to the sheet-shaped heating device 100#1, the closed circuit expands as a whole, and the area of ​​the PTC film heater constituting the heat generating unit 110 is doubled, and the inrush current becomes larger compared to the case of a single device. Therefore, by repeatedly connecting the sheet-shaped heating device 100, the inrush current also increases in proportion to the number of connected sheet-shaped heating devices 100, and the difference with the current consumption when the heat generating unit 110 is saturated also increases. Therefore, the current consumption when the sheet-shaped heating device 100 is saturated does not become an overcurrent, but in the case of an inrush current, an overcurrent may occur even with a number of units smaller than the number of units connected.

[0023] In order to suppress such an overcurrent, the control unit 140 is disposed between the power connection unit 120 and the power output unit 130, so that the current from the power connection unit 120 to the power output unit 130 is delayed until a certain requirement is met. As a result, even when a large number of devices are connected, the sheet-shaped heating device 100 can suppress the inrush current by generating an inrush current for each individual device.

[0024] The delay unit 141 delays the current acquired by the power supply connection unit 120 until the delay control unit 142 determines that a certain requirement is satisfied. The delay unit 141 is electrically connected to the power supply connection unit 120, the power supply output unit 130, and the delay control unit 142. The delay unit 141 is configured from a relay circuit, but may be other types of circuits or mechanical structures. The delay unit 141 may have a configuration of a conventionally known relay circuit that performs the above function, and therefore a detailed description thereof will be omitted.

[0025] The delay control unit 142 judges whether the control unit 140 has satisfied certain requirements, and if the certain requirements are satisfied, cancels the delay of the current from the power connection unit 120 to the power output unit 130 by the delay unit 141. Here, the certain requirements are: when a certain time has elapsed since the delay unit 141 started to delay the current; when the temperature of the PTC film heater 111 of the heat generating unit 110 is equal to or higher than a certain level; and when the current flowing through the PTC film heater 111 of the heat generating unit 110 is equal to or lower than a certain level. The above conditions are met.

[0026] First, among the requirements for delay control section 142, the requirements when a certain time has elapsed since delay section 141 started to delay the current will be described. When current begins to flow through the PTC film heater 111, the temperature rises until it reaches a saturated state in which the amount of heat generated by the PTC film heater 111 and the amount of heat radiated to the outside air are approximately equal. The temperature in the saturated state is constant for each PTC film heater 111. Therefore, the saturated state temperatures of PTC film heaters 111 of the same type are the same. In other words, the time it takes for the PTC film heater 111 to reach a certain temperature after current begins to flow is also constant.

[0027] Therefore, if the delay control unit 142 can confirm that a certain period of time c1 has elapsed since the current started to flow through the delay unit 141, even if the delay unit 141 cancels the delay in the current from the power connection unit 120 to the power output unit 130, the PTC film heater 111 has generated sufficient heat, and due to its PTC characteristics, the current consumption is smaller than the inrush current, and no overcurrent is generated even when the planar heating devices 100 are connected in series, that is, when the inrush current caused by the start of the connected planar heating devices 100 connected in a rosary shape is added. At this time, the delay control unit 142 has a timer function for measuring the certain period of time c1.

[0028] Next, among the requirements for delay control unit 142, the requirements when the temperature of PTC film heater 111 of heat generating unit 110 is equal to or higher than a certain temperature will be described. The PTC film heater 111 has PTC characteristics. Therefore, the resistance value of the PTC film heater 111 increases as the temperature of the PTC film heater 111 increases due to heat generation. However, the voltage remains constant. Generally, the current is inversely proportional to the voltage and the resistance value, so when the temperature of the PTC film heater 111 increases, the current consumption decreases.

[0029] In other words, if the PTC film heater 111 is at or above a certain temperature c2 that is close to the temperature in the saturated state, even if the delay unit 141 cancels the delay in the current from the power connection unit 120 to the power output unit 130, the current consumption is smaller than the inrush current due to its PTC characteristics, and no overcurrent occurs even if the inrush current caused by the start of the connected sheet heating device 100 connected in a rosary shape is added. At this time, the delay control unit 142 has a temperature sensor function for measuring the temperature of the PTC film heater 111.

[0030] Next, among the requirements for delay control unit 142, the requirement that the current flowing through PTC film heater 111 of heat generating unit 110 be equal to or less than a certain level will be described. If the current flowing through the PTC film heater 111 of the heat generating unit 110 is equal to or less than a certain amount c3, then naturally no overcurrent will occur even if the inrush current caused by the start of the connected planar heating device 100 connected in a rosary shape is added. At this time, the delay control unit 142 has the function of an ammeter for measuring the current flowing through the PTC film heater 111.

[0031] Exterior section 150 houses heat generating section 110, power connection section 120, power output section 130, and control section 140, and functions as the exterior of sheet-shaped warming device 100. Exterior section 150 is composed of surface fabric section 151, upper case 152, and lower case 153. Exterior section 150 is substantially rectangular parallelepiped when viewed from above, but may be of other shapes.

[0032] The outer cloth part 151 is a member that constitutes the front surface side of the exterior part 150. The outer cloth part 151 is a part that comes into contact with a user when the user stands on the exterior part 150. The outer cloth part 151 is placed on the upper case 152. The outer cloth part 151 has a substantially rectangular shape when viewed from above. The outer cloth part 151 is placed on the upper case 152, and is not particularly joined to the upper case 152, but may be joined by a method such as an adhesive.

[0033] The upper case 152 and the lower case 153 are combined to form a case that houses the heat generating unit 110, the power connection unit 120, the power output unit 130, and the control unit 140. Specifically, the case is a box-like case in which the lower case 153, which is a box-like case without a lid, and the upper case 152, which serves as a lid, are combined to form a box-like case with a lid. The upper case 152 has an outer fabric unit 151 disposed on top. The upper case 152 and the lower case 153 each have a hole at a position where they overlap when combined on their sides. In this embodiment, the power supply unit 123 that constitutes the power connection unit 120 is inside the exterior unit 150. Therefore, the power connection unit 120 needs to be extended from the exterior unit 150 through the above-mentioned hole to connect to an external power source. The holes may be provided on all the sides as shown in FIG. 1, or may be provided on only one of the sides.

[0034] In addition, the lower case 153 is divided into two layers, an upper layer and a lower layer, as shown in Figure 2 (b), with the heat generating section 110 being arranged in the upper layer and the power connection section 120, power output section 130, and control section 140 being arranged in the lower layer, but these may also be arranged in different locations.

[0035] FIG. 5 is a flowchart showing the operation of the sheet heating device 100 according to the embodiment. The processing of the planar heating device 100 will be described below with reference to the flowchart of Fig. 5. The flowchart of Fig. 5 starts when the planar heating device 100 is supplied with current via an outlet or the like, the power switch is turned on, and the device enters a power-on state. In any case, the following processing ends when the planar heating device 100 is unplugged from an outlet or the power switch is turned off, stopping the power supply and canceling the power-on state. In addition, in this flowchart, the planar heating device 100 is in a standalone state or in a state where another planar heating device 100 is connected to the power output unit 130.

[0036] In S101, the control unit 140 causes the power supply connection unit 120 to pass a current from the power supply to the heat generating unit 110, causing the sheet heating device 100 to generate heat.

[0037] In S102, the control unit 140 delays the current flowing from the power connection unit 120 to the power output unit 130. The control unit 140 flows the current from the power connection unit 120 to the delay unit 141. The delay unit 141 delays the current by not flowing the current to the power output unit 130 until the delay control unit 142 of the control unit 140 determines that a certain requirement is satisfied.

[0038] In S103, the control unit 140 determines whether or not the requirement for canceling the delay in the current flowing from the power connection unit 120 of the sheet heating device 100 to the power output unit 130 is satisfied. Here, the delayed release means that the control unit 140 causes a current to flow from the power connection unit 120 to the power output unit 130. When any of the following conditions is met: the passage of a certain amount of time, heat generation at or above a certain temperature, or current below a certain level, the control unit 140 cancels the delay in the current flowing from the power connection unit 120 to the power output unit 130. At this time, the current consumed by the sheet-shaped heating device 100 is sufficiently small compared to the inrush current, so even if another sheet-shaped heating device 100 is connected to the sheet-shaped heating device 100, adding the inrush current of the other sheet-shaped heating device 100 will not result in an overcurrent. If the conditions for canceling the delay are met, the process proceeds to S104, and if not, the process of S103 is repeated again.

[0039] In S104, the control unit 140 cancels the delay of the current flowing from the power connection unit 120 to the power output unit 130. By canceling the delay, the control unit 140 allows the current to flow from the power connection unit 120 to the power output unit 130. If another planar heating device 100 is connected to the planar heating device 100, the current flows to the other planar heating device 100 and the same process is performed. Also, in this flowchart, the planar heating device 100 is described as a single device or a state in which one other planar heating device 100 is connected to the planar heating device 100, but the same process is repeated even if more than one planar heating device is connected.

[0040] Next, a system in which a sheet-shaped heating device 100 is connected to a plurality of other sheet-shaped heating devices 100 will be described. FIG. 6 is a graph showing the relationship between the current consumption of the system of the sheet heating device 100 and time. When certain requirements are met, the control unit 140 cancels the delay in the current from the power connection unit 120 to the power output unit 130. Here, the requirement for canceling the delay is explained as a certain amount of time having elapsed since the delay unit 141 started to delay the current.

[0041] 4, the sheet-shaped heating devices 100 can be connected in a rosary-like fashion by repeatedly connecting the power connection parts 120 of other sheet-shaped heating devices 100 of the same type to the power output part 130 of the sheet-shaped heating devices 100. Also, each sheet-shaped heating device 100 delays the current flowing from the power connection part 120 to the power output part 130, and when the delay release requirements are met, releases the delay in the current from the power connection part 120 to the power output part 130.

[0042] For example, in the planar heating device 100#1 of Fig. 4, the planar heating device 100#2 is connected to the power output unit 130. When the planar heating device 100#1 is connected to a power source, the heat generating unit 110 starts to generate heat. In addition, the control unit 140 delays the current from the power connection unit 120 to the power output unit 130.

[0043] When the control unit 140 determines that a certain period of time has elapsed since the start of the delay, the control unit 140 cancels the delay to the power output unit 130, and current flows through the power output unit 130. The power output unit 130 is connected to the power connection unit 120 of the planar heating device 100#2, and the heating unit 110 of the planar heating device 100#2 starts generating heat. In addition, the control unit 140 of the planar heating device 100#2 delays the current from the power connection unit 120 to the power output unit 130. When the control unit 140 of the planar heating device 100#2 similarly determines that a certain time has elapsed since the start of the delay, the control unit 140 of the planar heating device 100#2 cancels the delay of the current to the power output unit 130, as in the case of the planar heating device 100#1. Then, the power connection unit 120 of the planar heating device 100#3 is connected to the power output unit 130 of the planar heating device 100#2, and the heat generating unit 110 of the planar heating device 100#3 starts to generate heat. In this embodiment, three devices are connected, but from then on, the same operation is performed up to the last connected planar heating device 100 in the rosary shape.

[0044] At this time, the inrush current of the sheet heating device 100 is a, and the current consumed when the PTC film heater 111 is saturated in a state where the amount of heat generated and the amount of heat radiated to the outside air are almost equal is b. In addition, the current b at the time of saturation is smaller than the inrush current a due to the PTC characteristics. When the sheet-shaped heating device 100#1 is started, the consumption current immediately thereafter is a because it is an inrush current, assuming that the delay time from the start of the delay to the power output unit 130 is t, and the delay cancellation requirement is met. Then, when the time t has elapsed from the start of the delay, the control unit 140 cancels the delay from the power connection unit 120 to the power output unit 130, and electricity is started to flow to the sheet-shaped heating device 100#2 connected to the power output unit 130. At this time, the consumption current of the sheet-shaped heating device 100#1 is the consumption current b when the PTC film heater 111 is saturated, and the sum of the consumption currents of the sheet-shaped heating devices 100#1 and #2 is a+b. In other words, the consumption current when the sheet-shaped heating devices 100#1 and #2 are started simultaneously is smaller than the inrush current 2a for two units.

[0045] When electricity starts to flow to the planar heating device 100#2, a delay is started in the current flowing from the power supply connection part 120 of the planar heating device 100#2 to the power supply output part 130. As with the planar heating device 100#1, when a time t (2t from the start of the delay of the planar heating device 100#1) has elapsed from the start of the delay of the current flowing from the power supply connection part 120 of the planar heating device 100#2 to the power supply output part 130, the control part 140 of the planar heating device 100#2 cancels the delay from the power supply connection part 120 to the power supply output part 130, and electricity is passed to the planar heating device 100#3 connected to the power supply output part 130 of the planar heating device 100#2. is started. At this time, the current consumption of the sheet heating device 100#2 alone is the saturated current consumption b because the temperature rise of the PTC film heater 111 is saturated, and the total current consumption of the sheet heating devices 100#1 and #2 is 2b. Also, the total current consumption of the sheet heating devices 100#1 to #3 is a+2b. In other words, this is smaller than the current consumption when the sheet heating devices 100#1 to #3 are started simultaneously, that is, the inrush current 3a for three devices.

[0046] Here, if the reference current for overcurrent is between a+2b and 3a, when three planar heating devices 100 are started at the same time, the inrush current is 3a, and an overcurrent will flow. However, when the planar heating devices 100 are connected as in this embodiment and started sequentially from #1, even if three devices are operated at the same time, the maximum current consumption is a+2b, which is the sum of the current consumption at saturation of planar heating devices 100#1 and #2 generated when planar heating device 100#3 is started, and the inrush current a of planar heating device 100#3 alone, and does not exceed the reference for overcurrent.

[0047] Thus, the planar heating device 100 of this embodiment comprises a heat generating section 110 composed of a PTC film heater, a power supply connection section 120 for outputting current to the heat generating section, a power supply output section 130 for outputting power supplied from the power supply connection section 120 to other planar heating devices, and a control section 140 for controlling the flow of electricity from the power supply connection section to the power supply output section. The control unit 140 delays the current from the power connection unit 120 to the power output unit 130 until certain requirements are met. The power output unit 130 outputs a current to another connected sheet-like heating device 100 when the consumption current is smaller than the inrush current, thereby making it possible to suppress the inrush current to a level lower than the inrush current of a sheet-like heating device having the same output as the total output of the sheet-like heating devices 100 when multiple sheet-like heating devices 100 are started simultaneously.

[0048] In this embodiment, the power output unit 130 is disposed in the center of the space covered by the heat generating unit 110, but it may be disposed in another position. For example, it may be disposed in the left front part of the lower case 153, or disposed outside the exterior part 150, or in another position other than the outer periphery.

[0049] In this embodiment, the exterior portion 150 has holes on all of its side surfaces, but it may have holes on only one of its side surfaces. Furthermore, although the power output unit 130 and the control unit 140 are disposed integrally, each of the components may be disposed in a different position.

[0050] In addition, in this embodiment, the current is delayed as a method for controlling the flow of electricity from the power connection unit 120 to the power output unit 130, but other methods may be used.

[0051] In this embodiment, three planar heating devices 100 are connected in a rosary shape, but depending on the output of the power source, a connection other than three devices, for example four or more devices, or a single device or two devices may be used.

[0052] Second embodiment FIG. 7 is a perspective view that illustrates an example of the configuration of a planar heating system 20 according to the second embodiment. The planar heating system 20 of this embodiment can be expanded to any size desired by the user by connecting multiple planar heating devices 200 in the planar direction. The planar heating system 20 is composed of two types of planar heating devices 200a as a parent unit to which power is supplied from the outside, and planar heating devices 200b as child units to which power is supplied through other planar heating devices including the planar heating device 200a. The planar heating system 20 shown in FIG. 7 has one planar heating device 200a and five planar heating devices 200b, three of which are connected along the left-right direction and two along the front-rear direction. When it is not necessary to distinguish between the parent unit and the child unit, they will be simply described as planar heating devices 200.

[0053] The planar heating device 200a and the planar heating device 200b have the same external size. The planar heating devices 200a and 200b are substantially rectangular when viewed from above, and are squares with the same length in the left-right direction and the same length in the front-back direction. Therefore, when a user connects the planar heating devices 200a and 200b to other planar heating devices 200a and 200b, they can be connected without worrying about the vertical and horizontal directions. The planar heating devices 200a and 200b of this embodiment have a left-right length and a front-back length of approximately 200 mm, but the left-right length and the front-back length may be in the range of 150 mm to 600 mm, and the dimensions are not limited.

[0054] FIG. 8 is an exploded perspective view of the sheet heating device 200a. The sheet-shaped heating device 200a includes a heat generating section 210, a pressure switch section 220, a base section 230, and a sheet-shaped section 240. The sheet-shaped section 240, the heat generating section 210, and the pressure switch section 220 are configured as a laminated body 260 stacked in this order from the top.

[0055] The planar portion 240 functions as a mat that covers the heating portion 210 and the pressure switch portion 220 from above. The planar portion 240 is substantially rectangular when viewed from above. The planar portion 240 may be formed of a single layer using, for example, felt or the like, or may be formed of multiple layers. When formed of multiple layers, the planar portion 240 can be formed of a surface portion that the user contacts and a cushion portion that provides elasticity to the user on the underside of the surface portion. The surface portion can be formed of sheet-like polyvinyl chloride (PVC) or the like so that a pattern can be applied. In addition, the planar portion 240 is folded downward from each of the four sides at the upper end, and covers the heating portion 210 and the pressure switch portion 220 from the sides. In addition, the planar portion 240 is folded toward the center from the four sides at the lower end, and covers parts of the heating portion 210 and the pressure switch portion 220 from the lower side as well. In this manner, the planar portion 240 encloses the heat generating portion 210 and the pressure switch portion 220 so as to integrate them together.

[0056] The heat generating section 210 generates heat according to the state of the pressure switch section 220. The heat generating section 210 is substantially rectangular when viewed from above. The heat generating section 210 is disposed between the planar section 240 and the pressure switch section 220. The heat generating section 210 has a PTC film heater 211 as a PTC heater, and a heat insulating material 212. The PTC film heater 211 converts electric current into heat. The heat insulating material 212 adjusts the radiation direction of the heat generated by the PTC film heater 211. By using the PTC film heater 211 in the heat generating section 210 in this way, it is not necessary to provide a separate temperature control section for controlling the temperature of the heat generating section 210 in order to maintain the heat generating section 210 in a saturated state. In this embodiment, a PTC film heater is used, but the present invention is not limited to this. For example, a fin-shaped or rod-shaped PTC heater may be used.

[0057] The pressure switch unit 220 detects the use state and non-use state of the planar heating device 200a. Here, the use state refers to a state in which the pressure switch unit 220 detects pressure when a user stands on the planar portion 240 of the planar heating device 200a. On the other hand, the non-use state refers to a state in which the pressure switch unit 220 does not detect pressure when a user does not stand on the planar portion 240 of the planar heating device 200a. That is, the pressure switch unit 220 can detect the use state of the planar heating device 200a by detecting pressure. Also, the pressure switch unit 220 can detect the non-use state of the planar heating device 200a by not detecting pressure.

[0058] The pressure switch section 220 has a substantially rectangular shape when viewed from above. The pressure switch section 220 is disposed below the heat generating section 210. The pressure switch section 220 has a sheet switch section 221 and a sheet attachment section 222. The sheet switch section 221 detects pressure applied to the planar section 240 of the planar heating device 200a. The sheet attachment section 222 is positioned below the sheet switch section 221 and protects the sheet switch section 221 from contacting the base section 230.

[0059] The base part 230 is in contact with the floor surface and supports a laminated body 260 in which the planar part 240, the heat generating part 210, and the pressure switch part 220 are laminated in this order from above, and a user standing on the planar part 240. The laminated body 260 is removably attached to the base part 230. The base part 230 is substantially rectangular when viewed from above, and is a substantially rectangular parallelepiped as a whole, with a space formed inside to store each component described below. The base part 230 has an upper case 231 and a lower case 241.

[0060] Fig. 9 is a perspective view showing an example of the configuration of upper case 231 in a state in which it is turned upside down. Fig. 10 is a bottom view of upper case 231 as seen from below. The upper case 231 is located above the base 230. The upper case 231 has an upper surface 232 and four side surfaces 233a to 233d. A board 234 is attached to the center of the upper case 231. A plurality of terminal blocks 235a to 235c are fixed to the outer edge of the board 234. A power supply connector 236 for connecting to an external power supply is attached to the side surface 233a of the planar heating device 200a as the parent unit. As shown in FIG. 7, when the power cord 201 is inserted into the power supply connector 236, power is supplied from the external power supply to the planar heating device 200a via the power cord 201. A two-core cable connected to the power supply connector 236 is wired to be connected to the terminal of the terminal block 235a fixed to the board 234. It should be noted that the sheet-shaped heating device 200b serving as the child unit does not have a power supply connection section 236 since power is input from another sheet-shaped heating device 200.

[0061] The planar heating devices 200a, 200b of the parent unit and the child unit have power input / output units 237a-237d on each of the four sides of the base unit 230 in common. Specifically, the power input / output units 237a-237d are attached to the side portions 233a-233d of the upper case 231 at the notched positions in the center of the width direction. The power input / output units 237a-237d are portions for inputting power from other planar heating devices 200 and outputting power to other planar heating devices 200. The power input / output units 237a-237d each have a pair of electrodes 238 (first electrode 238, second electrode 238) at positions separated in the width direction. The pair of electrodes 238 are sheet metal members having spring properties that protrude obliquely downward from the inside to the outside of the upper case 231. The two-core cables connected to the pair of electrodes 238 are wired so as to be connected to the terminals of terminal blocks 235 a and 235 b fixed to the substrate 234 .

[0062] As shown in FIG. 10, a circuit pattern 239 is formed on the substrate 234 so that the power input / output units 237a to 237d are electrically connected to each other. In the planar heating device 200a as the parent unit, power supplied from an external power source to the power connection unit 236 is supplied to the four power input / output units 237a to 237d via the circuit pattern 239. The power input / output units 237a to 237d of the planar heating device 200a as the parent unit function as a power output unit because they output the power supplied to the power connection unit 236 mainly to the other planar heating device 200b. On the other hand, in the planar heating device 200b as the child unit, the power input from the other planar heating device 200, for example, through the power input / output unit 237a, is supplied to the three power input / output units 237b to 237d via the circuit pattern 239. When a plurality of planar heating devices 200 are connected, the power input / output portions 237a to 237d of adjacent planar heating devices 200 are positioned adjacent to each other.

[0063] Furthermore, the top surface portion 232 of the upper case 231 has through holes 244 for guiding the cables connected to the PTC film heater 211 and the cables connected to the sheet switch portion 221 into the base portion 230. The cables connected to the PTC film heater 211 and the cables connected to the sheet switch portion 221 are inserted through the through holes 244, and then wired so as to be connected to terminals of terminal blocks 235b and 235c fixed to the substrate 234, respectively.

[0064] The lower case 241 is located below the base part 230. As shown in Fig. 8, the lower case 241 has a bottom part 242 and four side parts 243a to 243d. Each of the side parts 243a to 243d has a recess that is recessed toward the center of the bottom part 242 at the center in the width direction.

[0065] The planar heating system 20 also has a connection member 250 for inputting power from other planar heating devices 200 and outputting power to other planar heating devices 200 through the power input / output parts 237a-237d. The connection member 250 is disposed so as to straddle the two power input / output parts 237a-237d of adjacent planar heating devices 200, so that the adjacent power input / output parts 237a-237d are electrically connected to each other through the connection member 250. As shown in FIG. 8 and FIG. 9, the connection member 250 is positioned so as to straddle the two power input / output parts 237a-237d of adjacent planar heating devices 200, so that it overlaps the power input / output parts 237a-237d vertically, and enters into the notches in the width direction center of the side parts 233a-233d of the upper case 231 and into the recessed part in the width direction center of the lower case 241. The connection member 250 has a pair of electrodes 251 at positions spaced apart in the width direction on the upper surface. For example, a sheet metal member or a screen-printed electrode is used as the electrode 251. By disposing the connection member 250 so as to straddle the two power input / output units 237a to 237d of the adjacent planar heating devices 200, one electrode 251 of the pair of electrodes 251 is grounded to the first electrode 238 of the adjacent power input / output unit 237a to 237d and the first electrode 238 of the other adjacent power input / output unit 237a to 237d. In addition, the other electrode 251 of the pair of electrodes 251 is grounded to the second electrode 238 of the adjacent power input / output unit 237a to 237d and the second electrode 238 of the other adjacent power input / output unit 237a to 237d. Therefore, each time an additional sheet-shaped heating device 200 is installed, the sheet-shaped heating devices 200 are electrically connected to each other via the connecting member 250, whereby power can be supplied to the additional sheet-shaped heating devices 200.

[0066] In the example of the planar heating system 20 shown in FIG. 7, when the planar heating device 200 is adjacent to another planar heating device 200 on two of its four sides, it is electrically connected to the other planar heating device 200 via the connecting member 250 on those two sides. Also, when the planar heating device 200 is adjacent to another planar heating device 200 on three of its four sides, it is electrically connected to the other planar heating device 200 via the connecting member 250 on those three sides. Similarly, when the planar heating device 200 is adjacent to another planar heating device 200 on its four sides, it is electrically connected to the other planar heating device 200 via the connecting member 250 on those four sides. In this way, by electrically connecting all the adjacent planar heating devices 200 via the connecting member 250, the newly installed planar heating device 200 receives power from multiple paths through the other electrically connected planar heating devices 200. Therefore, even if one of the connected planar heating devices 200 fails and is unable to output power, power is input through a route passing through the other planar heating devices 200, so that the power input through the other planar heating devices 200 can be used to heat the heat generating section 210 or to output power to the other planar heating devices 200.

[0067] Fig. 11(a) is a diagram showing an example of the functional configuration of the sheet-shaped heating device 200a as a parent unit, and Fig. 11(b) is a diagram showing an example of the functional configuration of the sheet-shaped heating device 200b as a child unit. In Fig. 11, the same components as those described above are given the same reference numerals and the description is omitted as appropriate. In addition, each of the sheet-shaped heating devices 200a and 200b is a closed circuit by itself. As shown in FIG. 11(a), the planar heating device 200a serving as the parent unit has a heat generating section 210, a pressure switch section 220, a power connection section 236, power input / output sections 237a to 237d, a heat generating control section 261, and a power control section 262.

[0068] The heat generating unit 210 is electrically connected to the power supply connector 236 via the heat generation control unit 261 and the power supply control unit 262, and converts current from the power supply supplied to the power supply connector 236 into heat. The pressure switch unit 220 is electrically connected to the heat generation control unit 261. The power supply connector 236 is electrically connected to the power supply input / output units 237a to 237d via the power supply control unit 262. The power supply input / output units 237a to 237d are electrically connected to each other.

[0069] The heat generation control unit 261 controls the heat generation of the heat generation unit 210 according to the state of the pressure switch unit 220. The heat generation control unit 261 is electrically connected to the pressure switch unit 220 and the heat generation unit 210, and is located between the pressure switch unit 220 and the heat generation unit 210. In addition, the heat generation control unit 261 is electrically connected to the power supply connection unit 236 via the power supply control unit 262. Here, the heat generation control unit 261 acquires information on whether pressure is being detected or not detected from the pressure switch unit 220. When the pressure switch unit 220 detects pressure, the heat generation control unit 261 allows current from the power source supplied to the power source connection unit 236 to flow to the heat generation unit 210. On the other hand, when the pressure switch unit 220 does not detect pressure, the heat generation control unit 261 stops current from the power source supplied from the power source connection unit 236 to flow to the heat generation unit 210.

[0070] Therefore, when the planar heating device 200a is not in use, no current flows through the heat generating unit 210, and the heat generating unit 210 does not generate heat, thereby saving power. Even when no current flows through the heat generating unit 210, the power supplied from the power supply connection unit 236 is supplied to the power supply input / output units 237a to 237d via the power supply control unit 262, so that the power can be output from the power supply input / output units 237a to 237d to other planar heating devices 200. In other words, the power supply input / output units 237a to 237d can output power regardless of whether the pressure switch unit 220 detects the use state. Since a PTC heater is used for the heat generating unit 210, the heat generating control unit 261 does not need to control the temperature of the heat generating unit 210, but only needs to control whether or not to pass a current through the heat generating unit 210, and therefore the configuration of the heat generating control unit 261 can be simplified. The heat generating control unit 261 of this embodiment uses a thyristor, but may be another element or circuit. Also, the heat generating control unit 261 of this embodiment is mounted on the board 234 of the base unit 230, but may be mounted on a place other than the board 234.

[0071] The power supply control unit 262 controls the flow of electricity from the power supply connection unit 236 to the power supply input / output units 237a to 237d. The power supply control unit 262 is electrically connected to the power supply connection unit 236 and the power supply input / output units 237a to 237d, and is located between the power supply connection unit 236 and the power supply input / output units 237a to 237d. Here, when the power supply control unit 262 does not exist and the heat generation control unit 261 allows a current to flow to the heat generation unit 210, the power supply connection unit 236 and the heat generation unit 210 are directly connected. Furthermore, when one planar heating device 200b is connected in addition to the planar heating device 200a, and the power input / output parts 237a-237d of the planar heating device 200a are electrically connected to the power input / output parts 237a-237d of the other planar heating device 200b, the closed circuit expands as a whole, the area of ​​the PTC film heater constituting the heat generating part 210 also doubles, and the inrush current becomes larger compared to the case of a single unit. Therefore, by repeatedly connecting the planar heating device 200, the inrush current also becomes larger in proportion to the number of connected planar heating devices 200, and the difference with the current consumption when the heat generating part 210 is saturated also becomes larger. Therefore, if the consumption current of the planar heating device 200 is saturated, it does not become an overcurrent, but in the case of an inrush current, there is a possibility that an overcurrent will occur with a number of units smaller than the number of units connected.

[0072] In order to suppress such an overcurrent, the power supply control unit 262 sets a rise time T from when power is supplied from the power supply connection unit 236 until when power is supplied to the power supply input / output units 237a to 237d, and gradually supplies power to the power supply input / output units 237a to 237d. As a result, even when a large number of planar heating devices 200b as child units are connected, the power limited by the planar heating device 100a as the parent unit is input to the planar heating device 200b, so that the inrush current can be suppressed.

[0073] 12 is a graph for explaining the rise time T, where the horizontal axis indicates time and the vertical axis indicates voltage. Here, it is assumed that power of AC voltage 100 [V] is supplied to the power supply connection unit 236. Even when power is supplied from the power supply connection unit 236 at time 0 [t], the power supply control unit 262 does not immediately output the maximum voltage value to the power supply input / output units 237a to 237d, but gradually increases the voltage from 0 [V] as time passes, and outputs the voltage so that it becomes the maximum voltage value at the rise time T. The rise time T is a predetermined time between 30 seconds and 30 minutes, for example, but the specific time is not limited. 12 shows a case where the voltage is increased continuously from 0[V] to the maximum voltage value over time, but the voltage may be increased stepwise over time. Specifically, the voltage may be a1[V] from 0[t] to T×1 / 2[t], a2[V] (a2>a1) from T×1 / 2[t] to T[t], and increased stepwise to reach the maximum value after T[t].

[0074] The power supply control unit 262 uses phase control, which controls the output voltage by changing the ratio of on-time to off-time for each cycle of the AC current, to increase the ratio of on-time continuously or stepwise, thereby gradually increasing the voltage over time. The power supply control unit 262 of this embodiment uses a thyristor, but may be another element or circuit. In addition, the power supply control unit 262 of this embodiment is mounted on the board 234 of the base unit 230, but may be mounted on a location other than the board 234.

[0075] On the other hand, as shown in Fig. 11(b), the planar heating device 200b as a child unit has a heat generating section 210, a pressure switch section 220, power input / output sections 237a to 237d, and a heat generation control section 261. Unlike the planar heating device 200a as a parent unit, the planar heating device 200b as a child unit does not have a power connection section 236 and a power control section 262. Therefore, the planar heating device 200b as a child unit can reduce the manufacturing cost more than the planar heating device 200a as a parent unit.

[0076] The heat generating unit 210 is electrically connected to the power input / output units 237a-237d via the heat generation control unit 261, and converts current from a power source input to at least one of the power input / output units 237a-237d into heat. The pressure switch unit 220 is electrically connected to the heat generation control unit 261. The power input / output units 237a-237d are electrically connected to each other, and supply power input to at least one of them to the other power input / output units 237a-237d to be output to the other connected planar heating device 200b. The control by the heat generation control section 261 is similar to that of the sheet heating device 200a serving as the parent unit, and therefore a description thereof will be omitted.

[0077] FIG. 13 is a flowchart showing the operation of the sheet heating device 200. First, the process of the planar heating device 200a will be described with reference to the flowchart of Fig. 13. The flowchart of Fig. 13 starts when the power cord 201 is plugged into the power connection portion 236 of the planar heating device 200a and power is supplied to the planar heating device 200a from an external power source via the power cord 201. The flowchart ends when the power cord 201 is removed and power is no longer supplied to the planar heating device 200a. In this flowchart, the planar heating device 200a is in a standalone state or in a state where one other planar heating device 200b is connected to any one of the power input / output portions 237a to 237d.

[0078] In S201, the power supply control unit 262 gradually supplies the power supplied from the power supply connection unit 236 to the power supply input / output units 237a to 237d and the heat generating unit 210. Therefore, even if another sheet heating device 200b is connected, the inrush current can be suppressed.

[0079] In S202, the heat generation control unit 261 judges whether the planar heating device 200a is in use. Specifically, the heat generation control unit 261 judges that the planar heating device 200a is in use when the pressure switch unit 220 is in a state where it detects pressure, and judges that the planar heating device 200a is not in use when the pressure switch unit 220 is not in a state where it detects pressure. If the planar heating device 200a is in use, the process proceeds to S203, and if it is not in use, the process proceeds to S204.

[0080] In S203, the heat generation control unit 261 allows current from the power source supplied to the power source connection unit 236 to flow to the heat generation unit 210. Therefore, the heat generation unit 210 of the planar heating device 200a generates heat, so that the user resting on the planar heating device 200a can be warmed. In S204, the heat generation control unit 261 stops the current from the power source supplied from the power source connection unit 236 to the heat generation unit 210. Therefore, the heat generation unit 210 of the sheet heating device 200a stops generating heat, so that unnecessary heat generation can be suppressed and power saving can be achieved. Note that the heat generation control unit 261 may cause the heat generation unit 210 to generate less heat than in S203 by passing a smaller current than in S203. Thereafter, the heat generation control unit 261 repeats the processes from S202 to S204 until the power cord 201 is removed.

[0081] Next, the processing of the sheet heating device 200b will be described with reference to the flowchart of FIG. The process of the planar heating device 200b repeats the processes of S202 to S204, excluding S201, in the flow chart of Fig. 13. The following mainly describes the processes different from the process of the planar heating device 200a. Note that the power input from at least one of the power input / output units 237a to 237d is output from each of the power input / output units 237a to 237d to which the other planar heating devices 200 are connected. In S202, the heat generation control unit 261 determines whether or not the sheet-shaped heating device 200b is in use. If the sheet-shaped heating device 200b is in use, the process proceeds to S203, and if the sheet-shaped heating device 200b is not in use, the process proceeds to S204.

[0082] In S203, the heat generation control unit 261 allows a current from a power source inputted from at least one of the power input / output units 237a to 237d to flow to the heat generation unit 210. Therefore, the heat generation unit 210 of the planar heating device 200b generates heat, and the user placed on the planar heating device 200b can be warmed. In S204, the heat generation control unit 261 stops the current from the power source input from at least one of the power input / output units 237a to 237d from flowing to the heat generation unit 210. Therefore, the heat generation of the heat generation unit 210 of the sheet heating device 200b stops, so that unnecessary heat generation can be suppressed and power saving can be achieved. Note that the heat generation control unit 261 may pass a smaller current than in S203 so that the heat generation unit 210 does not generate as much heat as in S203. Thereafter, heat generation control section 261 repeats the processes from S202 to S204 until power cord 201 of sheet heating device 200a serving as the parent unit is removed.

[0083] Thus, the planar heating devices 200a and 200b of this embodiment include a rectangular base 230 that supports the pressure switch 220 and the PTC heater as the heat generating unit 210, and a plurality of power input / output units 237a-237d that are provided on the four sides of the base 230 and electrically connected to the PTC heater, and that output or input power between the planar heating devices 200a and 200b, and the plurality of power input / output units 237a-237d are electrically connected to each other. Therefore, even when a plurality of planar heating devices 200a and 200b are connected, it is possible to prevent the planar heating devices 200a and 200b from generating heat when not in use.

[0084] In addition, the power supply control unit 262 of the planar heating device 200a of this embodiment supplies power to the power input / output units 237a to 237d so that the voltage gradually increases over time after power is supplied from the power supply connection unit 236. Therefore, even when multiple planar heating devices 200a, 200b are connected, the inrush current can be suppressed.

[0085] In addition, the sheet-shaped heating device 200a of this embodiment has been described as having the power supply control unit 262, but this is not limited to this case, and the sheet-shaped heating device 200a may not have the power supply control unit 262. Even if the sheet-shaped heating device 200a does not have the power supply control unit 262, the heat generation control unit 261 allows current to flow to the heat generation unit 210 only when the sheet-shaped heating device 200a, 200b is in use, so that current is not passed to the heat generation unit 210 of the sheet-shaped heating device 200a, 200b that is not in use, thereby suppressing inrush current.

[0086] In addition, the planar heating devices 200a and 200b of this embodiment have been described as having the pressure switch unit 220 and the heat generation control unit 261, but this is not limited to this case, and they may not have the pressure switch unit 220 and the heat generation control unit 261. In this case, regardless of whether the planar heating devices 200a and 200b are in use or not, the heat generation unit 210 generates heat at any time by flowing a current through the heat generation unit 210, so that the user can be warmed no matter which planar heating device 200a or 200b the user stands on.

[0087] In addition, in this embodiment, the planar heating device 200a has been described as having power input / output parts 237a-237d on each of the four sides of the base part 230, but this is not limited to this case, and the side among the four sides on which the power connection part 236 is provided does not need to have a power input / output part. Further, in the present embodiment, the planar heating system 20 has been described as having a different configuration between the planar heating device 200a and the planar heating device 200b, but this is not limited to this case, and all may have the same configuration as the planar heating device 200a.

[0088] The present invention has been described above using various embodiments, but the present invention is not limited to the above-described embodiments, and modifications and variations are possible within the scope of the present invention, and the embodiments and modified examples may be combined as appropriate. [Explanation of symbols]

[0089] 100: Planar heating device 110: Heat generation section 111: PTC film heater 112: Insulation section 120: Power supply connection section 121: Plug 122: Power cable 123: Power supply section 130: Power supply output section 140: Control section 141: Delay section 142: Delay control section 150: Exterior section 151: Outer fabric section 152: Upper case 153: Lower case 20: Planar heating system 200: Planar heating device 200a, 200b: Planar heating device 210: Heat generation section 220: Pressure switch section 230: Base section 236: Power supply connection section 237a-237d: Power supply input / output section 261: Heat generation control section 262: Power supply control section

Claims

1. A heating portion constituted by a PTC heater; a power supply connection portion for supplying current to the heat generating portion; A power output unit that outputs the power supplied from the power connection unit to another planar heating device; a control unit that controls the flow of electricity from the power supply connection unit to the power supply output unit; A substantially rectangular base portion that supports the heat generating portion, The planar heating device is characterized in that the power output sections are provided on each of the four sides of the base section, electrically connected to the heat generating section, and electrically connected to each other.

2. The control unit is 2. The planar heating device according to claim 1, characterized in that a current is delayed from the power supply connection portion to the power supply output portion.

3. The control unit is A surface-shaped heating device as described in claim 1 or 2, characterized in that the current from the power connection portion to the power output portion is delayed until at least one of the following requirements is met: until a certain time has elapsed, or until the temperature of the PTC heater of the heat generating portion reaches or exceeds a certain temperature, or until the current flowing through the PTC heater of the heat generating portion falls below a certain temperature.

4. The control unit is 2. The planar heating device according to claim 1, wherein power is supplied to the power output section so that the voltage gradually increases over time after power is supplied from the power connection section.

5. The control unit is 5. The planar heating device according to claim 4, wherein power is supplied to the power output section so that the voltage increases stepwise over time after power is supplied from the power connection section.

6. 6. The sheet-shaped warming device according to claim 1, wherein the power supply connection portion is provided on one side of the base portion.

7. A planar heating system in which a plurality of planar heating devices are connected, One of the plurality of planar heating devices is A heating portion constituted by a PTC heater; a power supply connection portion for connecting to an external power supply and supplying a current to the heat generating portion; A power output unit that outputs the power supplied from the power connection unit to another planar heating device; a control unit that controls current flow from the power supply connection unit to the power supply output unit, The other planar heating device is: A surface heating system comprising a heat generating section constituted by a PTC heater, and not comprising the power supply connection section and the control section.

Images