Method for heating base plates

Abstract

The invention relates to a method for heating a plurality (N) of electrically heatable plates (1) laid in a covering plane (BE) by means of a control unit (15) as an interface (19) between a power grid having a predefined maximum value of the provided current intensity and the plates (1). According to the invention, subgroups (Ui, i = 1, 2, ... M; M<N) of plates (1) of the plurality of plates (1), which are each connected in parallel with the control unit (15), are successively subjected to current pulses with a level corresponding to the maximum value of the provided current intensity, and these successive applications of current pulses to the subgroups (Ui) are repeated until a sensor (20), connected to the control unit (15), for determining a value characteristic of the plate temperature of the plates (1) of one or more subgroups (Ui) detects a specified target value and the heating for these subgroups (Ui) is ended.

Description

[0001] Methods for heating floor slabs

[0002] The invention relates to a method for heating a plurality of electrically heated panels laid in a floor covering plane by means of a control unit as an interface between a power grid with a predetermined maximum current supplied to the panels and the panels, according to the preamble of claim 1. The invention further relates to a control unit for carrying out the method according to the invention according to the preamble of claim 5, a heating panel for bonding to a floor covering panel to form a panel for laying with a plurality of panels in a floor covering plane according to the preamble of claim 6, and an arrangement of a plurality of heated panels with a heating panel according to the invention for carrying out the method according to the invention, according to the preamble of claim 16.

[0003] When laying tiles indoors and outdoors, it is necessary to arrange the mostly square or rectangular tiles so that their surfaces form a common covering plane. These tiles are typically floor tiles used to create floor coverings for terraces, conservatories, and the like, but they can also be used for wall or ceiling coverings. It is also known to make the tiles used for creating such covering planes heatable, in particular electrically heated. Electrical heating is achieved using electric heating elements such as heating wires or heating mats, which are embedded in the tile and connected to a power supply.A known design for such heated plates involves providing a base plate with a surface plate, wherein the electric heating element is located in the base plate near the surface plate to heat it. Furthermore, it is known to equip such heated plates with a temperature sensor for determining the plate temperature. The temperature sensor can determine the plate temperature either directly by measuring the surface plate, or indirectly by measuring a temperature in the base plate that correlates with the surface plate temperature, from which the surface plate temperature can then be determined.

[0004] During installation, the electrically heated panels are connected to the mains power supply via their electrical connections. The heating function can be activated manually via a central switch or automatically via a timer that switches the panels on and off according to a schedule. It is also known to equip electrically heated panels with a control system that heats the panels to a set temperature and maintains it at that temperature. Care must be taken to ensure that the mains power supply is not overloaded by the electrical power drawn. For this purpose, power limiters are known that restrict the total power drawn by all the installed panels to a maximum value. In a mains power supply with a voltage of 230V and a maximum current rating of 16A, the maximum heating power consumption would be 3680W.This maximum heating power consumption must be distributed across the individual panels, which increases the time required to heat them up, significantly impacting ease of use, especially for spontaneous applications. Conventional solutions therefore suffer from the disadvantage that the limited power of a household electrical system can only provide either a high output for a few panels or a low output for many. In both cases, the heating process is lengthy and associated with corresponding costs. Furthermore, the cabling required for the panels is extensive, for example, for a panel measuring 60x60cm covering an area of ​​50m². 2Already 140 panels are required, which must be electrically connected to the building's electrical system. Integration into existing home automation systems, such as those currently available on the market for various control and regulation tasks in heating, cooling, or ventilation, or for shading a building, is therefore hardly possible with known solutions.

[0005] The object of the invention is therefore to provide a method for heating a plurality of electrically heated panels laid in a single layer, which on the one hand enables rapid heating of the panels and on the other hand also ensures that predetermined maximum values ​​for current and power consumption are not exceeded. Furthermore, suitable panels are to be provided.

[0006] These objectives are achieved by the features of claim 1.Claim 1 relates to a method for heating a plurality of electrically heated panels laid in a floor plane by means of a control unit as an interface between a power grid with a predetermined maximum value of the current supplied to the panels and the panels, wherein, according to the invention, it is proposed that subgroups of panels of the plurality of panels, each connected in parallel to the control unit, are successively subjected to current pulses with a magnitude corresponding to the maximum value of the supplied current, and that this successive subjecting of the subgroups to current pulses is repeated until a sensor connected to the control unit detects a predetermined setpoint value for determining a value characteristic of the panel temperature of the panels of one or more subgroups, and the heating for these subgroups is terminated.

[0007] The division into subgroups according to the invention serves the purpose of connecting the plates of a subgroup in parallel with the control unit, which acts as the interface to the power supply network. A current pulse with the predetermined maximum value of the current supplied by the power supply network to the plates is thus evenly distributed among the plates of the respective subgroup, provided the plates are identical. The predetermined maximum value of the current supplied by the power supply network corresponds to the aforementioned maximum current load of the power supply network, which is usually 16 A in a domestic network with a supply voltage of 230 V, because in residential buildings the individual electrical device circuits are generally protected by 16 A fuses.If a subgroup, for example, has 16 plates connected in parallel to the control unit, each with an internal resistance of 230 ohms, then each plate in this subgroup will be subjected to a current of 1 A during a current pulse of 16 A. With a supply voltage of 230 V, this corresponds to a heating pulse of 230 watts, with which the respective plate is heated. In a specific embodiment of the applicant's design, the internal resistance of the plates is, for example, approximately 260 ohms, so that with a supply voltage of 230 V, a current of approximately 0.875 A results, and thus a heating power of 200 watts.

[0008] The specified maximum current is supplied to a subgroup of the plates only as a current pulse of a predetermined duration, because other subgroups also need to be heated. Since the invention also provides for the subgroups to be successively supplied with such a current pulse, and for this successive supply of current pulses to be repeated several times, the current pulses are chosen to be correspondingly short. Regarding a specific choice for the duration of the current pulses, it is proposed, for example, that the pulse duration corresponds to the ratio of a predetermined period of the current pulses to the number of subgroups. The period, together with the pulse duration, determines the duty cycle of the current pulse.The number of subgroups is determined by the area-dependent number of panels to be heated and the specified maximum current supplied to the panels. With a specified maximum current pulse value of, for example, 16A and a supply voltage of 230V AC, the aforementioned 16 panels per subgroup are a practical value, as this results in a current of 1A per panel and heating pulses of 230 watts. This assumes each panel has a side length of 60x60cm and a surface area of ​​approximately 60m². 2Approximately 160 plates are required, resulting in 10 subgroups with 16 plates per subgroup. The period is chosen based on the thermal behavior of the plates and determines the time intervals at which a subgroup is subjected to a current pulse. The period will be chosen to be sufficiently short to allow no or only negligible cooling of the plate between individual heating pulses. For example, if the period is set to 10 seconds, the ratio of the specified period of the current pulses to the number of subgroups results in a pulse duration of one second.

[0009] Of course, regarding a specific choice for the duration of the current pulses, it could also be provided that, given a predetermined period of the current pulses, the pulse duration is controlled temperature-dependently for each subgroup, with the sum of the pulse durations of the current pulses for all subgroups corresponding to the predetermined period. For this purpose, several sensors will be provided, which are connected to a controller in the control unit, for example, a PID controller, that regulates the current pulses.If, for example, the sensor detects a lower temperature or a poorer heating characteristic for one subgroup than for the other subgroups, and the target temperature has already been reached for other subgroups, the controller can lengthen or shorten the pulse duration of the current pulses for the individual subgroups accordingly, provided that the sum of the pulse durations of the current pulses for all subgroups corresponds to the specified period. In the example above with 10 subgroups, if, for example, the sensor detects a lower temperature or a poorer heating characteristic for one subgroup than for the other subgroups, and the target temperature has already been reached for four subgroups, the controller can divide the pulse duration for the first-mentioned subgroup into 5 seconds and for the last four subgroups into 0 seconds, because the sum again equals the specified period of 10 seconds.As soon as a sensor connected to the control unit detects a predefined setpoint value for the plate temperature of one or more subgroups, heating for those subgroups is stopped. It may be possible to use only one sensor for this purpose, provided that this sensor measures a value characteristic of the plate temperature of all plates. If the sensor detects that the plate temperature of one or more subgroups falls below a predefined threshold, heating for those subgroups is resumed. The predefined threshold can be equal to the setpoint or lower. For example, if the setpoint is 25°C, the threshold for reheating could be 20°C.

[0010] The method according to the invention has several advantages. Firstly, it significantly reduces cabling effort because each subgroup only needs to be connected to the control unit via a single supply cable, and the panels of the same subgroup only need to be connected to each other, as will be explained in more detail below. In the example above, for a surface area of ​​approximately 60 m² 2 Using panels with sides measuring 60x60cm, 10 subgroups of 16 panels each, and therefore 10 supply cables, are sufficient to connect to a control unit. This also simplifies integration with conventional home automation systems, such as those currently available on the market for various building control and regulation tasks, as will be explained in more detail later.

[0011] Furthermore, the method according to the invention enables rapid and cost-effective heating of the plates, while ensuring at all times that predetermined maximum values ​​for current and power consumption are not exceeded. With an initial plate temperature of, for example, 0°C and a target plate temperature of 25°C, heating 16 plates of a subgroup costs approximately €3 at current electricity prices. Maintaining the target temperature over a period of 8 hours requires only one-hundredth of this cost, i.e., about €0.03, because the coating plates are mostly made of materials with good heat storage properties and only short current pulses are used.

[0012] To carry out the method according to the invention, a heating plate for bonding to a covering plate to form a plate for laying with a plurality of plates in a covering plane is proposed, in which it is provided that it is formed from a fiber-reinforced plastic plate, and a heating element is designed as an electrical conductor applied in a spiral or meandering shape on a first side of the fiber-reinforced plastic plate, and on a second side of the plastic plate opposite the first side, an incoming connection cable and an outgoing connection cable are provided, each designed as a two-pole cable, wherein a first pole of the incoming and the outgoing connection cable are electrically connected to each other and a second pole of the incoming and the outgoing connection cable are electrically connected to each other.and the first pole of the incoming connecting cable is electrically contacted with a first end of the conductor track, and a second pole of the incoming connecting cable is electrically contacted with a second end of the conductor track.

[0013] The incoming connection cable of the first plate in a subgroup corresponds to, or is connected to, the aforementioned power supply cable. The outgoing connection cable of this plate corresponds to, or is connected to, the incoming connection cable of a second plate in this subgroup. All subsequent plates in this subgroup are connected to each other in this manner. The outgoing connection cable of the last plate in this subgroup is electrically insulated with an end cap. In this way, a parallel connection of the plates in a subgroup is achieved, with the heating element of each plate in direct contact with the connection cables. The internal electrical resistance of a plate is thus largely determined by the heating element. For example, the internal resistance of the conductor track can be 240–280 ohms.In a specific implementation of the applicant's design, the internal resistance of the plates is approximately 260 ohms, resulting in a current of approximately 0.875 A and thus a heating power of 200 watts at a supply voltage of 230 V AC. For safety reasons, a thermal switch can be provided, connected in series with the circuit trace, which shuts off the plate if a maximum permissible temperature, for example 55°C, is exceeded. The thermal switch can, for example, be a bimetallic switch.

[0014] The fiber-reinforced plastic sheet can be provided with transverse bores for the passage of connecting cables from the second side of the fiber-reinforced plastic sheet to the opposite, first side of the plastic sheet, wherein the electrical contacts of the conductor track to the connecting cables are arranged on the first side of the plastic sheet. Preferably, however, it is proposed that the fiber-reinforced plastic sheet be provided with transverse vias by which the first pole of the incoming connecting cable is electrically contacted with a first end of the conductor track and a second pole of the incoming connecting cable is electrically contacted with a second end of the conductor track, wherein the electrical connections of the connecting cables to the vias of the conductor track are arranged on the second side of the plastic sheet.The connections themselves are conventionally designed as solder joints, electrically insulated using a two-component potting compound or insulating varnish, as will be explained in more detail below. This insulating varnish provides strain relief, protecting the connections. The second side of the plastic plate, opposite the first, can also be covered with insulating foam, which covers the connecting cables and thus provides additional strain relief. The entire heating plate is double-insulated according to protection class II.

[0015] Fiber-reinforced plastic sheets, with a thickness of approximately 0.3 mm, are available with compressive strengths perpendicular to the sheet of approximately 500 MPa and flexural strengths of approximately 350 MPa, thus fulfilling all requirements for penetration protection in supported floor slabs. The heating plate itself therefore becomes penetration protection, which is a significant advantage when supported on bearings. To create a heating plate, fiber-reinforced plastic sheets are provided with a conductive track running across the surface of the fiber-reinforced plastic sheet by vapor deposition of an electrically conductive material such as copper, or by photolithographic or milling processes.This conductive track is densely embedded in a layer of a viscous, applyable, and hardening fluid, such as an adhesive or insulating varnish. The hardened fluid is in close physical contact with the conductive track, and the enclosure within the hardened fluid also provides a moisture-tight seal for the assembly. Electrical contact via the incoming and outgoing connecting cables enables connection to an external power source. When current flows through the conductive track, it generates the heat required to warm the substrate in a manner known per se. Due to the use of a fiber-reinforced plastic sheet and a viscous, applyable, and hardening fluid such as an adhesive or insulating varnish, sufficient electrical insulation is achieved.

[0016] The electrical connections can also be densely embedded in a terminal block arranged on the second side of the fiber-reinforced plastic sheet. This block consists of a viscous, applyable, and hardening fluid, preferably in the form of an insulating varnish, particularly a solder mask. As already mentioned, this solder mask not only ensures electrical insulation of the terminal block but also strain relief for the connections. Additionally, the thermal switch, which can be a bimetallic switch, for example, can also be arranged in the terminal block and densely embedded in the insulating varnish.

[0017] The fiber-reinforced plastic plate can be, for example, a glass fiber reinforced plastic plate (GFRP plate). Preferably, an FR4 plate is proposed. FR4 is an epoxy resin-glass fabric composite material that not only exhibits good adhesion for copper but also has flame-retardant properties and minimal water absorption. This material is therefore very suitable for a base plate according to the invention. Furthermore, FR4 has a glass transition temperature of 130°C–140°C, so that the structural integrity of the heating plate is always guaranteed within the planned thermostat-controlled operating range of a maximum of 100°C.

[0018] The heating plate is preferably provided with optically marked areas for the application of adhesive. These optically marked areas can run, for example, along the edges of the heating plate and along its diagonals. The adhesive serves to attach the heating plate to a backing plate on site before the resulting plate, consisting of the heating plate and backing plate, is installed. The adhesive forms a minimal bridge to the backing plate and ensures that the insulation layer cannot be chafed by the copper traces of the conductor. Furthermore, the trapped air efficiently transfers the heat to the backing plate. The FR4 plate also provides sufficient penetration protection.

[0019] To attach the heating plate to a base plate, it is proposed that the heating plate's length and width correspond to, or are only slightly smaller than, the length and width dimensions of the base plate, and that its fiber-reinforced plastic surface is bonded to the base plate. The heating plate, with its electrical conductors, thus lies close or nearly close to the base plate, ensuring good thermal contact between the conductors and the base plate. Constructing a heating plate using electrical conductors applied to a printed circuit board material allows for a uniform distribution of the heating power across the surface of the base plate, with a comparatively high proportion of the heating area to the total surface area of ​​the heating plate.The proposed configuration also makes it possible to use the entire surface of the heating plate as a carrier for the conductor track and thus to heat the largest possible area of ​​the coating plate. In particular, the embodiment according to the invention makes it possible to heat the entire surface of the coating plate, including its edge and corner areas, which not only ensures uniform heating of the coating plate but is also particularly advantageous when the plates are to be kept ice-free.

[0020] In the following, an arrangement of a plurality of heated plates with a heating plate according to the invention is proposed for carrying out the method according to the invention, wherein the subgroups of plates, each connected in parallel to the control unit, are each connected to the control unit via their own interface, and sensors are provided for determining a value characteristic of the plate temperature of the plates of one or more subgroups, which are connected to further interfaces of the control unit. This arrangement simplifies the connection to conventional building control systems, such as those currently available on the market for various control tasks in the heating, cooling, or ventilation sector or for shading a building.Such home automation systems provide electrical interfaces that can be controlled by control software and can therefore be used for the control units mentioned here. In the arrangement described above, the respective subgroups of the plates can be connected to their respective home automation interfaces within the framework of the inventive method. In addition, the sensor, in particular a temperature sensor, is also connected to its own interface. It may well be possible to use only one sensor for this purpose, provided that this sensor measures a value characteristic of the plate temperature of all plates. Otherwise, several sensors can be used. Subsequently, the home automation system is programmed so that, after a manual or programmed start signal, each plate interface is successively supplied with current pulses as described above.This process is repeated until the interface for the home automation system's temperature sensor indicates that the target temperature has been reached. If the interface for the home automation system's temperature sensor indicates that a predefined limit has been undershot, the heating process restarts until the heating of the panels is stopped by a manual or programmed end signal.

[0021] The invention will be explained in more detail below with reference to exemplary embodiments and the accompanying figures. These figures show...

[0022] Fig. 1 shows a perspective view of an embodiment of a plate according to the invention comprising a covering plate and a heating plate according to the invention, seen from below.

[0023] Fig. 2 shows a perspective view of an embodiment of a heating plate according to the invention, seen from above.

[0024] Fig. 3 is a schematic cross-sectional view along the section line AA of Fig. 1,

[0025] Fig. 4a shows a schematic view of an embodiment of the heating plate according to the invention as shown in Fig. 2, seen from above, to illustrate a possible contacting method using bores for the passage of connecting cables without a conductor track and thermal switch.

[0026] Fig. 4b shows a schematic view of the heating plate according to the invention as shown in Fig. 4a from above, with conductor track and thermal switch; Fig. 5 shows the electrical circuit diagram of a heating plate according to the invention.

[0027] Fig. 6 shows the electrical circuit diagram of the parallel connection of the heating plates of a subgroup of the plates,

[0028] Fig. 7 shows a representation illustrating one embodiment of the arrangement of a subgroup of 16 electrically heated panels laid in a single surface plane.

[0029] Fig. 8 shows a representation illustrating one embodiment of the electrical connections in a subgroup of 16 electrically heated plates of Fig. 7, and the

[0030] Fig. 9 illustrates one embodiment of connecting several subgroups of heated floor panels according to the invention to the interfaces of a home automation system. Reference is first made to Fig. 1 to explain one embodiment of a panel 1 according to the invention, comprising a covering panel 2 and a heating panel 3 according to the invention. The covering panel 2 is attached to the heating panel 3 via an adhesive bond and slightly protrudes beyond the heating panel 3. The covering panel 2 can be made of, for example, wood, concrete, porcelain stoneware, ceramic, or natural stone. Furthermore, an incoming connection cable 8 and an outgoing connection cable 9 with respective connectors 17 are shown, with which the connection cables 8 and 9 of the panels 1 can be connected to each other or, via a supply cable 16, to a control unit 15, as will be explained in more detail below.

[0031] The heating plate 3 is explained in more detail with reference to Figures 2-4. It comprises a fiber-reinforced plastic plate 4 (see also Figure 3) on which an electrical conductor 5 runs on a first side of the fiber-reinforced plastic plate 4. This conductor is densely embedded in a layer 6 of a viscous, applyable, and hardening fluid, for example, an insulating varnish, arranged on the first side of the fiber-reinforced plastic plate 4. The heating plate 3 is bonded to the base plate 2 with its first side. The insulating varnish is in close physical contact with the conductor 5, so that the inclusion in the hardened fluid also ensures that the assembly is sealed against moisture. An FR4 plate is preferably proposed for the fiber-reinforced plastic plate 4. Such fiber-reinforced plastic plates 4 are available with a thickness of approximately 0.Available in 3mm thickness with compressive strengths in the vertical direction of approximately 500 MPa and flexural strengths of approximately 350 MPa, these panels meet all requirements for penetration protection of supported floor slabs. Heating plate 3 thus itself acts as penetration protection for plate 1.

[0032] To construct the heating plate 3, the fiber-reinforced plastic plate 4 is provided with the conductor track 5 by vapor deposition of an electrically conductive material such as copper or by photolithographic processes. The conductor track runs spirally or meanderingly across the surface of the fiber-reinforced plastic plate 4 and terminates at both ends in a connection field 7 for the connecting cables 8, 9 (see also Fig. 4a and Fig. 4b).

[0033] For bonding to the covering plate 2, the heating plate 3 in the illustrated version is provided with optically marked areas for the application of an adhesive (see Fig.

[0034] 2) These optically marked areas can be designed, for example, as adhesive lines 13 running along the edges of the heating plate 3 and along its diagonals, as shown in Fig. 2. The adhesive serves to fix the heating plate 3 to a covering plate 2 on site before the resulting plate 1, consisting of the heating plate 3 and the covering plate 2, is laid. The adhesive forms a minimal bridge to the covering plate 2 and ensures that the layer 6 cannot be chafed by the copper traces of the conductor track 5. In addition, the trapped air efficiently transfers the heat to the covering plate 2.

[0035] The heating plate 3 can further be provided with a thermal insulating foam 10 on its side facing away from the base plate 2, as shown in Fig. 3. The insulating foam 10 reduces heat loss downwards, i.e., in the direction opposite to that of the base plate 2. The insulating foam 10 is also preferably attached to the fiber-reinforced plastic plate 4 by means of an adhesive bond and extends over almost the entire surface of the heating plate 3, with areas only being left open at the corners of the heating plate 3 where the plate 1 rests on the pedestals 21 in its operating position (see also Fig. 7). PE foam, for example, can be used for the insulating foam 10.

[0036] Figure 4a shows that the heating plate 3 can be provided with bores 11 that cross the heating plate 3. These bores 11 serve to guide the connecting cables 8, 9 from the first side of the fiber-reinforced plastic plate 4 to a second side of the plastic plate 4 opposite the first side, with the electrical contacts 12 of the conductor track 5 to the connecting cables 8, 9 being arranged on the first side of the plastic plate 4 in the connection field 7. However, it would also be possible to arrange the connection field 7 on the opposite, second side of the plastic plate 4.For this purpose, the fiber-reinforced plastic plate 4 is provided with vias traversing the plastic plate 4, by which the first pole PI of the incoming connecting cable 8 is electrically contacted with a first end of the conductor track 5 and a second pole P2 of the incoming connecting cable 8 is electrically contacted with a second end of the conductor track 5, wherein the electrical connections of the connecting cables 8, 9 to the vias of the conductor track 5 are arranged on the second side of the plastic plate 4. The electrical connections are thus provided in a connection field 7 arranged on the second side of the fiber-reinforced plastic plate and densely embedded in a viscous, applyable and hardening fluid, which is preferably designed as an insulating varnish, in particular as a solder mask.This solder mask not only ensures electrical insulation of the terminal block 7, but also strain relief for the connections. Additionally, a thermal switch 14, which may be a bimetallic switch, for example, can be arranged in the terminal block 7 and tightly embedded in the insulating varnish. The connections themselves are made in the conventional manner as solder joints. The second side of the plastic plate 4, opposite the first, is, as mentioned, covered with insulating foam 10, with the insulating varnish of the terminal block 7 and the insulating foam 10 providing additional strain relief for the connecting cables 8 and 9.

[0037] The incoming connection cable 8 and the outgoing connection cable 9 are each designed as two-pole cables, wherein a first pole PI of the incoming connection cable 8 and a first pole PI of the outgoing connection cable 9 are electrically connected to each other via contact 12a in the terminal block 7, and a second pole P2 of the incoming connection cable 8 and a second pole P2 of the outgoing connection cable 9 are electrically connected to each other via contact 12b in the terminal block 7. The first pole PI of the incoming connection cable 8 is also electrically connected to a first end of the conductor track 5 via contact 12a, and the second pole P2 of the incoming connection cable 8 is electrically connected to a second end of the conductor track 5 via contact 12b.

[0038] The contacts 12 of the conductor track 5 to the connecting cables 8, 9 are also visible in Fig. 4b, where in Fig.

[0039] Figure 4b also shows the conductor track 5 and a thermal switch 14, which is connected in series with the conductor track 5 and causes the plate 1 to shut down when a maximum permissible temperature is exceeded. For the sake of clarity, the conductor track 5 and the thermal switch 14 are not shown in Figure 4a.

[0040] Figure 5 shows the electrical circuit diagram of a heating plate 3 for the contact type 12 described above. The first pole PI of the incoming connecting cable 8 and the outgoing connecting cable 9 is, for example, the phase conductor, and the second pole P2 of the incoming connecting cable 8 and the outgoing connecting cable 9 is the neutral conductor. The conductor 5 is connected in parallel to these two poles P1 and P2 and is shown in Figure 5 as the internal resistance R. The circuit diagram in Figure 5 also shows the thermal switch 14, which is connected in series with the conductor 5 and, for example, switches off the plate 1 if a maximum permissible temperature of 55°C is exceeded. The internal resistance R of the heating plate 3 is, for example, about 260 ohms, so that with a supply voltage of 230V AC via the first pole PI a current of about 0.875 A and thus a heating power of 200 watts results.

[0041] The parallel connection of a subgroup Ui (i=l, 2, ...M; M <N) einer Mehrzahl von N Platten 1 wird in weiterer Folge anhand der Fig. 6-8 erläutert . In den Fig. 6-8 wird dabei von einer Untergruppe Ui bestehend aus 16 Platten 1 (M=16) ausgegangen. In der Fig. 9 wird in weiterer Folge ein Beispiel mit insgesamt 48 Platten 1 (N=48 ) gezeigt, die in drei Untergruppen Ul, U2, U3 von j eweils 16 Platten angeordnet sind .

[0042] Fig. 6 shows the electrical circuit diagram of the parallel connection of the 16 plates 1.1, 1.2, ... 1.16 of a subgroup Ui of the plates 1. The circuit diagram of the individual heating plates 3 corresponds to the embodiment of Fig.

[0043] 5. Fig. 6 can be read together with Fig. 8, which shows a diagram illustrating the electrical connections of a subgroup Ui of 16 electrically heated plates 1, arranged, for example, in a 4x4 grid. The subgroup Ui is connected to the control unit 15 via a single supply cable 16 (see also Fig. 9). The incoming connection cable 8 of a first plate 1.1 of the subgroup Ui is connected to the supply cable 16 via the connector 17. The outgoing connection cable 9 of this plate 1.1 corresponds to the incoming connection cable 8 of a second plate 1.2 of this subgroup Ui, or is connected to it via connector 17. All further plates 1 of this subgroup Ui are connected to each other in this way. The outgoing connection cable 9 of the last plate 1.16 of this subgroup Ui is electrically insulated by an end cap 18.Figure 7 shows a representation illustrating the arrangement of a subgroup Ui of 16 electrically heated slabs 1 laid in a surface level BE, arranged in a grid pattern and supported on bearings 21.

[0044] Figure 9 shows an illustration illustrating the connection of three subgroups Ul, U2, and U3 of heated plates 1 according to the invention to the interfaces 19 of the control unit 15, which can be, for example, a conventional home automation system. Such home automation systems are available for various control tasks in heating, cooling, or ventilation, or for shading a building, and generally provide electrical interfaces 19 that can be controlled by control software. In the above-mentioned arrangement, the three subgroups Ul, U2, and U3 can be connected to their respective interfaces 19 of the control unit 15 within the framework of the method according to the invention. In addition, one of the plates 1 is also provided with a sensor 20, in particular a temperature sensor, which is connected to its own interface 19.Subsequently, the control unit 15 is programmed so that, following a manual or programmed start signal, each interface 19 of the subgroups Ul, U2, U3 is successively supplied with current pulses of, for example, one second each and a current of 16 A. This process is repeated until the interface 19 for the sensor 20 of the home automation system indicates a corresponding input signal that the target temperature of, for example, 25°C has been reached. If the interface 19 for the sensor 20 of the home automation system indicates a corresponding signal that a predefined limit of, for example, 20°C has been undershot, the heating process starts again until the heating of the plates is stopped following a manual or programmed end signal.

[0045] The invention thus provides a method for heating a plurality N of electrically heated panels 1 laid in a floor surface BE, which on the one hand enables rapid heating of the panels 1 and on the other hand also ensures that predetermined maximum current consumption values ​​are not exceeded. It also significantly reduces the wiring effort because each subgroup Ui only needs to be connected to the control unit 15 via a single supply cable 16, and the panels 1 of the same subgroup Ui only need to be connected to each other. Therefore, integration with conventional building automation systems, such as those currently available on the market for various control and regulation tasks in heating, cooling, or ventilation systems, or for shading a building, is also simplified.

Claims

Patent claims:

1. Method for heating a plurality (N) of electrically heated slabs (1) laid in a floor level (BE) by means of a control unit (15) as an interface (19) between a power network with a predetermined maximum value of the current supplied to the slabs (1) and the slabs (1), characterized in that subgroups (Ui, i=l, 2, ...M; M <N) von j eweils in Parallelschaltung mit der Steuerungseinheit ( 15) verbundenen Platten ( 1 ) der Mehrzahl an Platten ( 1 ) nacheinander mit Stromimpulsen mit einer dem Maximalwert der bereitgestellten Stromstärke entsprechenden Höhe beaufschlagt werden und diese aufeinander folgende Beaufschlagung der Untergruppen (Ui) mit Stromimpulsen wiederholt wird, bis ein mit der Steuerungseinheit ( 15) verbundener Fühler (20) zur Ermittlung eines für die Plattentemperatur der Platten ( 1 ) einer oder mehrerer Untergruppen (Ui) charakteristischen Werts einen vorgegebenen Sollwert detektiert und das Aufheizen für diese Untergruppen (Ui) beendet wird.

2. Method according to claim 1, characterized in that the pulse duration of the current pulses corresponds to the ratio of a predetermined period of the current pulses to the number of subgroups (Ui).

3. Method according to claim 1, characterized in that, for a given period of the current pulses, a temperature-dependent control of the pulse duration of the current pulses is carried out for each subgroup (Ui), wherein the sum of the pulse durations of the current pulses for all subgroups (Ui) corresponds to the given period.

4. Method according to one of claims 1 to 3, characterized in that when the sensor (20) detects that the temperature of one or more subgroups (Ui) falls below a predetermined limit value (GW), the heating of these subgroups (Ui) is resumed.

5. Control unit ( 15) designed to carry out a method according to any one of claims 1 to 4 .

6. Heating plate (3) for bonding to a covering plate (2) to form a plate (1) for laying with a plurality of plates (1) in a covering plane (BE), characterized in that it is formed from a fiber-reinforced plastic plate (4), and a heating element is designed as an electrical conductor (5) applied in a spiral or meandering pattern on a first side of the fiber-reinforced plastic plate (4), and on a second side of the plastic plate (4) opposite the first side, an incoming connecting cable (8) and an outgoing connecting cable (9) are provided, each being designed as a two-pole cable, wherein a first pole (PI) of each incoming and outgoing connecting cable (8, 9) is electrically connected to each other and a second pole (P2) of each incoming and outgoing connecting cable (8, 9) is electrically connected to each other. are,and the first pole (PI ) of the incoming connecting cable ( 8 ) is electrically contacted with a first end of the conductor track (5) and a second pole (P2 ) of the incoming connecting cable ( 8 ) is electrically contacted with a second end of the conductor track (5 ., 7. Heating plate (3) according to claim 6, characterized in that the internal resistance of the conductor track (5) is 240-280 ohms.

8. Heating plate (3) according to claim 7, characterized in that the internal resistance of the conductor track (5) is 260 ohms.

9. Heating plate (3) according to one of claims 6 to 8, characterized in that the fiber-reinforced plastic plate (4 ) is provided with vias transverse to the plastic plate (4 ) by which the first pole (PI ) of the incoming connecting cable ( 8 ) is electrically contacted with a first end of the conductor track (5) and a second pole (P2 ) of the incoming connecting cable ( 8 ) is electrically contacted with a second end of the conductor track (5), wherein the electrical connections of the connecting cables ( 8, 9) to the vias of the conductor track (5) are arranged on the second side of the plastic plate (4 ).

10. Heating plate (3) according to one of claims 6 to 9, characterized in that the fiber-reinforced plastic plate (4) is an FR4 plate.

11. Heating plate (3) according to one of claims 6 to 10, characterized in that the conductor track (5) is densely embedded in a layer (6) of a viscous, applyable and hardening fluid arranged on the first side of the fiber-reinforced plastic plate (4).

12. Heating plate (3) according to one of claims 9 to 11, characterized in that the electrical connections are densely embedded in a connection field (7) arranged on the second side of the fiber-reinforced plastic plate (4) made of a viscous, applyable and hardening fluid.

13. Heating plate (3) according to claim 11 or 12, characterized in that the viscous, applyable and hardening fluid is an insulating varnish.

14. Heating plate (3) according to one of claims 6 to 13, characterized in that it is provided with optically marked areas for the application of an adhesive.

15. Plate (1) with a heating plate (3) according to any one of claims 6 to 14 and a covering plate (2), characterized in that the heating plate (3) corresponds in its length and width to the length and width dimensions of the covering plate (2) or is only slightly smaller, and is bonded to the covering plate (2) with its first side of the fiber-reinforced plastic plate (4).

6. Arrangement of a plurality of heatable plates (1) with a heating plate (3) according to any one of claims 6 to 14 and a control unit (15) according to claim 5, characterized in that subgroups (Ui, i=l, 2, ...M; M<N) der j eweils in Parallelschaltung mit der Steuerungseinheit ( 15 ) verbundenen Platten ( 1 ) j eweils über eine eigene Schnittstelle ( 19 ) mit der Steuerungseinheit ( 15 ) verbunden sind und Fühler ( 20 ) zur Ermittlung eines für die Plattentemperatur der Platten ( 1 ) einer oder mehrerer Untergruppen (Ui ) charakteristischen Werts vorgesehen sind, die mit weiteren Schnittstellen ( 19 ) der Steuerungseinheit ( 15 ) verbunden sind .

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