Radiofrequency signal control system for a domestic electrical appliance, comprising a coupler on a printed circuit

Abstract

Radiofrequency signal control system for a domestic electrical appliance, comprising a printed circuit board coupler The invention relates to a radiofrequency signal control system for a domestic electrical appliance (2) controlled by a management unit (3), the system comprising: - a radiofrequency signal coupler (10), comprising a line section (13a) printed on a printed circuit board (9) having a free end (13b) and being connected in bypass of a transmission line (13) printed on the printed circuit board (9) of which a first end is connected to an electrical conductor (5), the coupler (10) comprising at least one coupling line (15a) of which a part extends without electrical contact, parallel to the line section (13a);- a radiofrequency unit (7) for transmitting and / or receiving radiofrequency signals comprising an input and / or output (Sa) of radiofrequency signals electrically connected to the coupler, - a blocking circuit (12) of the radiofrequency signals, printed on the printed circuit board and connected by one end only, on the transmission line (13). Figure for the abstract: Fig. 2.;

Description

Title of the invention: Radiofrequency signal control system for a domestic electrical appliance, comprising a coupler on a printed circuit Technical field

[0001] The present invention relates to the technical field of radiofrequency signal control of a domestic electrical appliance supplied with electrical energy by an electrical supply network.

[0002] The present invention finds particularly advantageous applications in the field of controlling electromechanical actuators used in a closing or solar protection installation using screens, blinds or shutters for example. Prior art

[0003] In the state of the art, the electromechanical actuators implemented in a closing or protection installation are known to be equipped with a radiofrequency receiver and transmitter provided with a receiving and transmitting antenna, making it possible to increase the sensitivity and therefore the transmission range between a radiofrequency transmitter, nomadic or fixed, and the radiofrequency receiver.

[0004] The receiving and transmitting antenna is a sensitive and fragile element. In addition, the actuator is often arranged in a metal casing which requires the antenna to be moved outside the casing to preserve the sensitivity of the radiofrequency receiver.

[0005] Many technical solutions have been proposed for using the actuator's power supply cable to house part of the antenna, or for using a phase conductor and / or a neutral conductor as the antenna, either by direct coupling or by partial coupling.

[0006] For example, patent EP 2 109 226 describes a device for controlling by radiofrequency signals a domestic electrical appliance supplied with electrical energy by an electrical supply network. The device for controlling by radiofrequency signals comprises a radiofrequency unit for transmitting and / or receiving radiofrequency signals. The device for controlling by radiofrequency signals comprises a first electrical conductor and a second electrical conductor for supplying electrical energy.

[0007] The radio frequency signal control device comprises an antenna electrically connected to the radio frequency unit. At least one of the two electrical conductors of the electrical supply network constitutes a receiving antenna or transmitter for radio frequency signals. The radio frequency unit comprises an output and / or an input for radio frequency signals electrically connected to a connection point of a coupler.

[0008] The radiofrequency signal control device comprises a printed circuit board on which turns forming a winding are printed to produce the coupler. The electrical connection between the radiofrequency signal output and / or input of the radiofrequency unit and the connection point of the coupler makes it possible to electrically connect the radiofrequency signal output and / or input of the radiofrequency unit to an additional terminal of the winding located between the two end terminals of the winding.

[0009] The coupler is connected via a first end to the first electrical conductor of the radiofrequency signal control device and via a second end to a reference voltage of the radiofrequency unit. The coupler is crossed between its first and second ends by the current of the electrical supply network which supplies the domestic electrical appliance.

[0010] However, this radio frequency signal control device has the disadvantage of producing the coupler by means of a winding formed by turns printed on the printed circuit board of the radio frequency signal control device. In the case where a strong current supplies the domestic electrical appliance, such a winding formed by printed turns has a significant footprint on the printed circuit board because of the width of the tracks of the printed circuit board producing the winding and the electrical conductor electrically connected to the winding.

[0011] Indeed, the dimensioning of these tracks of the printed circuit board is linked to the value of the supply current of the domestic electrical appliance passing through the coupler consisting of the winding formed by printed turns. Consequently, the location occupied by the winding on the printed circuit board increases the cost of obtaining the printed circuit board of the radiofrequency signal control device and requires a housing in the domestic electrical appliance of significant size for the assembly of the printed circuit board.

[0012] Consequently, the production of the printed circuit board with such a winding formed by printed turns is complex to industrialize, causes difficulties in guaranteeing the reliability of the radiofrequency signal control device, during mass production, and increases the cost of obtaining the printed circuit board of the radiofrequency signal control device.

[0013] In an attempt to overcome these drawbacks, patent EP 3 221 970 proposes a device for controlling a domestic electrical appliance using radiofrequency signals, making it possible to install a coupler on a printed circuit board of the appliance. control device, while overcoming the problems linked to the current value of the power supply network circulating in the coupler and / or to the value of the working frequency of the radiofrequency unit. According to this patent, the coupler is formed by a transmission line printed on the printed circuit board, a first end of the printed transmission line being electrically connected to the first electrical conductor of the control device while the second end of the printed transmission line is electrically connected to a first reference voltage. Furthermore, the connection point of the coupler constituted by the printed transmission line is arranged between the first and second ends of the printed transmission line.In addition, the control device comprises an antenna electrically connected to the radio frequency unit via one of the electrical conductors of the electrical supply network, the first electrical conductor of the control device being connected to the electrical supply network, and the coupler adapting the output and / or input impedance of the radio frequency unit to the impedance of the antenna.

[0014] A disadvantage of the control device described by this patent is the need to produce the coupler parallel to the transmission line. This constraint limits the possibilities of configuring the printed circuit on the printed circuit board. Furthermore, the coupler is connected to a reference voltage which does not allow electrical isolation between the power supply network and the radiofrequency unit. It should be noted that the operation of the control device described by this patent is sensitive to the load and the impedance of the electromechanical actuator. Statement of the invention

[0015] The present invention aims to remedy the drawbacks of the prior art by proposing a system for controlling a domestic electrical appliance using radiofrequency signals, making it possible to completely install the radiofrequency signal coupler on a printed circuit board without requiring electronic components.

[0016] Another object of the invention is to provide a system for controlling a domestic electrical appliance using radiofrequency signals, designed to optimize the circulation of radiofrequency signals between the antenna and the radiofrequency unit.

[0017] Another object of the invention is to propose a control system whose behavior is insensitive to the variation in impedance of the domestic electrical appliance.

[0018] To achieve these objectives, the control system according to the invention comprises: - a printed circuit board; - a radiofrequency signal coupler, comprising at least one line of transmission printed on the printed circuit board in an extension direction and a first end of which is connected to the first electrical conductor; - a radiofrequency unit for transmitting and / or receiving radiofrequency signals comprising a radiofrequency signal input and / or output electrically connected to a PI connection point of the coupler, characterized in that: - the coupler comprises a line section printed on the printed circuit board having a free end and being connected as a branch of the transmission line, at a connection point, the coupler comprising at least one coupling line printed on the printed circuit board, a coupling part of which extends without electrical contact, parallel to the line section; - a radiofrequency signal blocking circuit, printed on the printed circuit board and connected at one end only, to the transmission line, a second end of which is connected to the management unit, this blocking circuit being connected at a connection point between the connection point of the coupler line section and the management unit.

[0019] According to a characteristic of the invention, the coupling line of the coupler is configured to form a quarter-wave line.

[0020] According to an exemplary embodiment, the coupling line comprises two printed coupling parts to have a configuration in the form of a U surrounding, without electrical contact, the line section.

[0021] According to another exemplary embodiment, the coupling line of the coupler is printed to have a rectilinear configuration or in the form of an L.

[0022] According to another exemplary embodiment, the line section is printed on the printed circuit board in a direction not parallel to the direction of extension of the transmission line.

[0023] Advantageously, the directions of the line section and the transmission line form an angle between them of between 30° and 150°.

[0024] According to a preferred example of implementation, the coupler is configured so as to obtain an attenuation of less than 3dB between the connection point of the coupler and the first end of the transmission line connected to the first electrical conductor.

[0025] According to a characteristic of the invention, the blocking circuit comprises a portion of line printed on the printed circuit board having a free end.

[0026] According to another characteristic of the invention, the line portion of the blocking circuit has an electrical length adapted so that, depending on the length of the transmission line between the connection point of the coupler and the connection point of the blocking circuit, the radiofrequency signals are blocked at the connection point of the coupler, with an attenuation greater than 10 db.

[0027] Advantageously, the blocking circuit comprises an electrical length between the connection point of the coupler and the free end of the line portion equal to Lambda / 2.

[0028] Another object of the invention is to propose a domestic electrical appliance comprising a radiofrequency signal control system according to the invention. Brief description of the drawings

[0029] [Fig-1] [Fig.l] is a simplified electrical diagram of a system in accordance with the invention of controlling a domestic electrical appliance by radiofrequency signals.

[0030] [Fig.2] [Fig.2] represents an example of the realization of an electrical diagram arranged on a printed circuit board implemented in the radio frequency signal control system of a domestic electrical appliance.

[0031] [Fig.3] [Fig.3] is a diagram of another example of the embodiment of a coupler placed implemented in the control system according to the invention.

[0032] [Fig.4] [Fig.4] is a diagram of another example of the embodiment of a coupler placed implemented in the control system according to the invention.

[0033] [Fig.5] [Fig.5] is a diagram of another example of the embodiment of a coupler placed implemented in the control system according to the invention Description of the embodiments

[0034] As can be seen from the figures, the subject of the invention relates to a control system 1 using radiofrequency signals for a domestic electrical appliance 2 controlled by a management unit 3. The domestic electrical appliance 2 and the management unit 3 are supplied with electrical energy by an electrical power cable 4 comprising a first electrical conductor 5, for example neutral, and a second electrical conductor 6, for example phase. Furthermore, the electrical power cable 4, which is supplied with electrical energy by the electrical power supply network, may comprise a protective electrical conductor. The protective electrical conductor of the electrical power cable 4 is connected to the ground and to a metal structure of the domestic electrical appliance 2.

[0035] According to an advantageous application, the domestic electrical appliance 2 comprises an electromechanical actuator for a home automation installation for closing or solar protection. As described for example in patent application EP 3 221 970, the electromechanical actuator comprises an electric motor 2a housed in a winding tube of a screen of the roller shutter or blind type. It should be noted that the control system 1 according to the invention is suitable for controlling, as a domestic electrical appliance 2, for example, a ventilation or alarm device, a system for detecting meteorological parameters equipping a building or its external environment.

[0036] The control system 1 comprises a radiofrequency unit 7 for transmitting and / or receiving radiofrequency signals making it possible to control the domestic electrical appliance 2. This radiofrequency unit 7 is powered by an energy converter of any type known per se, not shown and connected to the electrical supply network 4. This radiofrequency unit 7 comprises an output and / or an input Sa of radiofrequency signals coming from a localized or centralized control device 8 such as a remote control or another radiofrequency device.

[0037] The radiofrequency signals emitted by the control device 8 comprise commands for controlling the domestic electrical appliance and more precisely, according to the example illustrated, the electric motor 2a. The control commands received by the radiofrequency unit 7 are transmitted to the management unit 3 of the electric motor 2a, so as to control a rotational drive in a first direction of rotation or in a second direction of rotation or to stop the rotational drive. In an advantageous embodiment, the radiofrequency unit 7 also makes it possible to transmit to the control device 8, via its input / output Sa, signals carried by radiofrequency waves and comprising, in particular, information relating to the operation of the electric motor 2a.

[0038] The control system 1 comprises a printed circuit board 9 on which the components of the management unit 3 and the radiofrequency unit 7 are mounted. The first electrical conductor 5 and the second electrical conductor 6 are also arranged partly on the printed circuit board 9.

[0039] According to the invention, the input / output Sa of the radiofrequency unit 7 is electrically connected to a connection point PI of a coupler 10 of the radiofrequency signals carried by an electrical conductor of the electrical power cable 4, namely the first electrical conductor 5 in the example illustrated. According to the invention, the coupler 10 is arranged on the printed circuit board 9 on which is also arranged a blocking circuit 12 of the radiofrequency signals, in the direction of the domestic electrical appliance 2, as will be explained in detail in the remainder of the description.

[0040] As can be seen from Figures 1 and 2, the radiofrequency signal coupler 10 comprises at least one transmission line 13 printed on the printed circuit board 9 in a rectilinear extension direction XX in the illustrated example. A first end of this transmission line 13 is connected to the first electrical conductor 5 at a point A while the second end of this transmission line 13 is connected to the management unit 3 of the electric motor 2a, at a point B of the first electrical conductor 5 supplying the management unit 3.

[0041] The coupler 10 comprises a line section 13a printed on the circuit board printed 9 by being connected in derivation of the transmission line 13, at a connection point Pc. This line section 13a has, opposite its end connected to the transmission line 13, a free end 13b in open circuit. According to an advantageous characteristic of embodiment, the line section 13a is printed on the printed circuit board 9 in a direction not parallel to the direction of extension XX of the transmission line 13. Advantageously, the directions of the line section 13a and the transmission line 13 form between them an angle [3 of between 30° and 150°. In the example illustrated in [Fig. 2], the line section 13a is printed on the printed circuit board 9, advantageously in a direction perpendicular to the direction of extension XX of the transmission line 13 ([3 = 90°). In the embodiment example illustrated in [Fig.5], the line section 13a is printed on the printed circuit board 9, in a direction forming an angle [3= 45° relative to the transmission line 13. .

[0042] In the same sense, it should be noted that in the figures, the line section 13a is printed on the printed circuit board 9 with a rectilinear shape. Of course, the line section 13a can be printed on the printed circuit board 9 with one or more curvatures.

[0043] The coupler 10 comprises a coupling line 15 printed on the printed circuit board 9 and having at least one part 15a extending without electrical contact, parallel to the line section 13a. This coupling line 15 is printed on the printed circuit board 9 having at least one free end 15e in open circuit and, on the opposite side, one end connected to a point C for connection with the input / output Sa of the radiofrequency unit 7.

[0044] Advantageously, the coupling line 15 of the coupler is configured to form a quarter-wave line. Conventionally, the coupling line 15 is formed by a conductor printed on the printed circuit board having an electrical length which is substantially equal to a quarter of the wavelength of the frequency of the radiofrequency signals used for controlling the domestic electrical appliance. Whatever the frequency, the electrical length of the coupling line 15 is close to a quarter of the wavelength of this frequency.

[0045] This coupling line 15 can have different configurations. According to an advantageous variant illustrated in [Fig. 2], the coupling line 15 of the coupler is printed to have a configuration in the form of a U surrounding, without electrical contact, the line section 13a. According to this example, the coupling line 15 comprises two coupling parts 15a extending on either side of the line section 13a and parallel to each other and to the line section 13a. These two coupling parts 15a comprise free ends 15e in open circuit, located near the transmission line 13 and opposite ends connected to each other by a connecting segment 15b connected to the connection point C. This U-shaped coupling makes it possible to minimize coupling losses. This solution also makes it possible to obtain a compact shape.

[0046] In the illustrated example, the coupling parts 15a are rectilinear since the line section 13a is rectilinear. Of course, as explained above, the line section 13a can be printed on the printed circuit board 9 in a non-rectilinear direction. In this case, the coupling parts 15a of the coupling line 15 are printed on the printed circuit board 9 by extending without electrical contact, in a non-rectilinear direction, parallel to the line section 13a.

[0047] [Fig. 3] illustrates another exemplary embodiment in which the coupling line 15 of the coupler 10 is printed to have a rectilinear configuration. According to this example, the coupling line 15 of the coupler comprises a coupling part 15a extending without electrical contact, parallel to the line section 13a, substantially over the entire length of the line section 13a. This coupling part 15a has a free end 15e in open circuit, located near the transmission line 13 and an opposite end connected to the connection point C. It should be noted that in the exemplary embodiment illustrated in [Fig. 5], the coupling line 15 of the coupler 10 is printed to have a rectilinear configuration parallel to the line section 13a extending in a direction forming an angle [3= 45° with respect to the transmission line 13.The coupling line 15 of the coupler 10 is printed parallel to the line section 13a on either of its sides.

[0048] [Fig. 4] illustrates another embodiment in which the coupling line 15 of the coupler is printed to have an L-shaped configuration. According to this example, the coupling line 15 of the coupler comprises a first coupling part 15a extending without electrical contact, parallel to the line section 13a, substantially over the entire length of the line section 13a, extending at right angles, beyond the free end 13b of the line section 13a, by a second coupling part 15b. This first coupling part 15a has a free end 15e in open circuit, located near the transmission line 13 while the second coupling part 15b is connected to the connection point C.

[0049] Regardless of the embodiment of the coupler 10, it should be noted that there is no electrical contact between the first electrical conductor 5 and the antenna line of the radio frequency unit 7 (the input / output Sa of the radio frequency unit 7). The electrical isolation between the electrical line and the radio frequency line is achieved by the natural galvanic isolation provided by the printed circuit board 9. The width of the lines of the coupler 10 (namely the coupling parts 15a and the line section 13a) as well as the spacing between the lines of the coupler are adjusted to allow impedance matching between the connection point Pc and the connection point C so as to maximize the transfer of radiofrequency energy.

[0050] According to an advantageous characteristic, the coupler 10 is configured so as to obtain an attenuation of less than 3dB between the connection point Pc of the coupler and the first end of the transmission line 13 connected to the first electrical conductor 5.

[0051] According to another characteristic of the invention, the control system 1 comprises the blocking circuit 12 for the radiofrequency signals making it possible to ensure rejection of the radiofrequency signals towards the motor 2a. This blocking circuit 12 is printed on the printed circuit board 9 while being connected by only one end, to the transmission line 13 at a connection point Pr located between the connection point Pc of the line section 13a of the coupler and the management unit 3. The blocking circuit 12 thus comprises a portion of line 12a printed on the printed circuit board 9 while having a free end 12b in open circuit so that this portion of line 12a can be considered as electrically connected in parallel to the transmission line 13. This portion of line 12a is connected to the transmission line 13 at the connection point Pr.

[0052] In the embodiments illustrated in Figures 2 to 4, the line portion 12a and the line section 13a of the coupler are printed on the printed circuit board 9, on the same side of the transmission line 13. In the embodiment illustrated in [Fig.5], the line portion 12a and the line section 13a of the coupler are printed on the printed circuit board 9, on either side of the transmission line 13.

[0053] This radiofrequency signal blocking circuit 12, which is designed to direct its radiofrequency signals towards the electrical line and not towards the motor 2a, is done by means of an open-circuit “stub”. The property of this stub is to bring back a virtual “short circuit” for the radiofrequency signals on the line from the first electrical conductor 5 to the motor 2a but also a virtual high-impedance “open circuit” at the connection point Pc, at the desired frequency. The geometry of this blocking circuit can be produced in different ways, depending in particular on the constraints of space available on the printed circuit board 9.

[0054] The line portion 12a of the blocking circuit 12 has an electrical length adapted so that, depending on the length of the transmission line 13 between the connection point Pc of the coupler and the connection point Pr of the blocking circuit, the radiofrequency signals are blocked at the connection point of the coupler Pc, with an attenuation greater than 10db. Ideally, the attenuation is greater than 20db. Thus, the line of the first electrical conductor 5 has, at the connection point Pc, a high impedance preventing the radiofrequency signals from going to the motor 2a. connection Pc of the coupler and the free end 12b of the line portion 12a equal to Lambda / 2 (Lambda being the wavelength), corresponding to an electrical length of approximately 180°. The width of the transmission line 13 is adjusted to allow the continuous signal to be transmitted without losses and to maintain an impedance close to 50 Ohms. The radiofrequency signals are naturally directed towards the line of the first electrical conductor 5. The blocking circuit 12 advantageously makes it possible to force the radiofrequency signals to circulate from point A of the transmission line 13 to the connection point C and vice versa with a loss of less than 3 dB, while preventing the passage of these radiofrequency signals from the connection point C to the point B of the transmission line but also from point A of the transmission line 13 to the point B of the transmission line, with an isolation of at least 10 dB.

[0056] An advantage of the invention is that the coupler is completely printable on a printed circuit and does not require any electronic components. All functions are performed by simple transmission lines. These transmission lines can be made in different ways such as microstrip line, stripline or coplanar line. Since the lines are made on an epoxy dielectric substrate and in particular of the FR4 type, all line lengths or widths will be dependent on the physical and electrical characteristics of the substrate (Example: permittivity, height, etc.). All line lengths are dependent on the frequency of use which in the illustrated example is 2.4GHz.

[0057] According to an exemplary embodiment, in the case where the working frequency of the radiofrequency unit 7 is 2.4 GHz, the length in air of the coupler 10 is 30 mm and the length in air of the “stub”, i.e. from the connection point Pc to the free end 12b, is 60 mm. It should be noted that the actual length on the printed circuit board 9 will be smaller than the length in air since the dielectric permittivity of the printed circuit board 9 must be taken into account.

[0058] Of course, the radiofrequency signal control system can also operate in another radiofrequency band, which can extend, in particular, between 400 MHz and 4 GHz, and which can take, in particular, values ​​of the order of 433 MHz or 868 MHz.

Claims

Claims

1. System for controlling by radiofrequency signals a domestic electrical appliance (2) controlled by a management unit (3) and supplied with electrical energy by a first electrical conductor (5) and a second electrical conductor (6) of an electrical supply network, the system comprising: - a printed circuit board (9); - a coupler (10) of the radiofrequency signals, comprising at least one transmission line (13) printed on the printed circuit board in an extension direction (XX) and comprising a first end connected to the first electrical conductor (5) and a second end connected to the management unit, the coupler (10) comprising at least one coupling line (15) printed on the printed circuit board;- a radiofrequency unit (7) for transmitting and / or receiving radiofrequency signals comprising an input and / or output (Sa) of radiofrequency signals electrically connected to a connection point (PI) of the coupling line of the coupler, characterized in that: - the coupler (10) comprises a line section (13a) printed on the printed circuit board having a free end (13b) and being connected in derivation of the transmission line (13), at a connection point (Pc), the coupling line (15) comprising a coupling part (15a) extending without electrical contact, parallel to the line section (13a); - and in that a blocking circuit (12) for radiofrequency signals is printed on the printed circuit board and connected by one end only, to the transmission line (13) at a connection point (Pr) between the connection point (Pc) of the line section (13a) of the coupler and the management unit (3).;

2. Control system according to claim 1 according to which said at least one coupling line (15) of the coupler (10) is configured to form a quarter-wave line.

3. Control system according to one of the preceding claims, wherein said at least one coupling line (15) comprises two coupling parts (15a) printed to have a configuration in the form of a U surrounding, without electrical contact, the line section (13a).

4. Control system according to one of claims 1 or 2 according to which said at least one coupling line (15) of the coupler is printed to have a rectilinear configuration or in the form of an L.

5. Control system according to one of the preceding claims, wherein the line section (13a) is printed on the printed circuit board (9) in a direction not parallel to the direction of extension (XX) of the transmission line.

6. Control system according to the preceding claim, wherein the directions of the line section (13a) and the transmission line (13) form between them an angle [3 of between 30° and 150°.

7. Control system according to one of the preceding claims, wherein the coupler (10) is configured so as to ensure an attenuation of less than 3dB between the connection point (Pc) of the coupler and the first end of the transmission line (13) connected to the first electrical conductor.

8. Control system according to one of claims 1 to 7, wherein the blocking circuit (12) comprises a line portion (12a) printed on the printed circuit board (9) having a free end (12b).

9. Control system according to claim 8 according to which the line portion (12a) of the blocking circuit (12) has an electrical length adapted so that depending on the length of the transmission line (13) between the connection point (Pc) of the coupler and the connection point (Pr) of the blocking circuit (12), the radiofrequency signals are blocked at the connection point of the coupler (Pc), with an attenuation greater than 10db.

10. Control system according to one of claims 8 or 9 according to which the blocking circuit (12) comprises an electrical length between the connection point (Pc) of the coupler and the free end (12b) of the line portion (12a) equal to Lambda / 2, Lambda being the wavelength.

11. Domestic electrical appliance characterized in that it comprises a control system (1) by radiofrequency signals according to one of claims 1 to 10.

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