EP3092715A1

EP3092715A1 - Invisible, contactless switch device

Info

Publication number: EP3092715A1
Application number: EP15701554.6A
Authority: EP
Inventors: Roberto Airoldi
Original assignee: Open App
Current assignee: AIROLDI, ROBERTO
Priority date: 2014-01-09
Filing date: 2015-01-07
Publication date: 2016-11-16
Also published as: ZA201605464B; EP2894785A1; WO2015104480A1; AU2015205454A1; US20160329893A1; AU2015205454B2; US10193550B2

Abstract

The invention relates to a switch device for attaching behind an opaque wall (32) such that it is invisible from outside said wall and for controlling the connection of an electrical appliance (44), said device comprising a first module (10) and a second module (12) for carrying out the connection between the electrical appliance and a power supply source. The first module comprises a capacitive detector (16) provided with a capacitor on a printed circuit board which changes value when a user on the outside places their hand (34) close to the wall, at the site where the device is attached. The capacitor is contained within a metal frame, the function of which is to delimit the capacitive field created by the capacitor within the plane of the board and to maximise said field perpendicularly to the plane of the board.

Description

Invisible and non-contact switching device

Technical area

The present invention relates to the control of connection and disconnection of electrical appliances of all kinds, including lighting fixtures in care facilities, and particularly relates to an invisible switching device and contactless.

State of the art

The control of connection and disconnection of electrical devices is usually carried out by means of electromechanical switching devices such as buttons, switches or levers connected to electrical devices in general by wire cabling.

However, these switching devices do not fulfill the necessary hygiene conditions and can cause the transmission of contagious diseases. This disadvantage is particularly important in the hospital environment where it can lead to the spread of nosocomial diseases. In addition, the repeated handling of these devices visually results in their rapid degradation and the wear of parts making up the device and resulting in their failure.

The problems mentioned have been partly solved by the use of switching devices that do not require the user to touch the device to perform the connection control or disconnection, the control being performed through a capacitive sensor. Such a connection device is described in document AU 2013205636. However, in this document, the device is apparent since the wall behind which the device is located comprises a transparent window. This transparency is made necessary for the system to be efficient because the capacitive detector would not fill not his role without this window. In addition, this is corroborated since it is specified in the document that for capacitive sensing to take place, it is necessary to place the object in front of the detector for a long time.

Presentation of the invention

The main object of the present invention is therefore to provide a switching device comprising a capacitive detector which is placed behind a wall of any material whatsoever and which is activated by the hand of the user without it touching the wall .

A first object of the invention is therefore an invisible and non-contact switching device adapted to be fixed behind an opaque wall so as not to be visible from the outside of the wall and intended to control the connection of at least one electrical apparatus and comprising at least a first module and a second module adapted to perform the connection between the electrical apparatus and a power source, the first module comprising a capacitive detector adapted to change value when the hand or any other part of the body of a user outside is placed near the wall at the location where the device is attached. The device is characterized in that the capacitive sensor on a printed circuit board includes a capacitor having a first metal electrode consisting of a solid circle and a second metal electrode surrounding the first electrode and being concentric with the first electrode. here, the set of two electrodes being included in a metal frame whose function is to delimit the capacitive field due to the capacitance formed by the two electrodes in the plane of the card and to make this field perpendicular to the plane of the map .

A second object of the invention is a switching device comprising a plurality of modules identical to the first module mentioned above which communicate through communication means with a second module identical to the second module mentioned above, adapted to perform the connection or disconnection of at least one electrical device via switches controlled by a microcontroller.

Brief description of the figures

Other objects, objects and features of the invention will appear more clearly on reading the following description given with reference to the drawings in which:

FIG. 1 is a block diagram showing an embodiment of the switching device according to the invention;

FIG. 2 diagrammatically represents a capacitive detector characterizing the switching device according to

The invention;

FIG. 3 diagrammatically represents another capacitive detector characterizing the switching device according to the invention

Figure 4 is a schematic representation of the loading of the reference capacity; and

- Figure 5 is a block diagram showing an embodiment of the switching device according to the invention comprising a plurality of modules and at least one electrical device.

Detailed description of the invention

The switching device according to the invention shown in FIG. 1 comprises a first module 10, a second module 12 and a communication means 14 which enables the first module 10 to communicate with the second module 12.

The module 10 comprises a capacitive detector 16 connected by the outputs 18, 20 and 22 to a microcontroller The power source 26, a battery, a battery, a photovoltaic cell or an AC / DC converter supplies the electrical energy necessary for the operation of the microcontroller 24.

As previously mentioned, the first module 10 is placed behind a wall 32 such as a partition or a wall. This wall is made of any material such as wood, concrete or even metal such as copper. The first module 10 is activated when an operator approaches his hand 34 or any other part of the body near the wall 32 at a distance of between 2 cm and 5 cm.

The second module 12 which is connected to the first module by the communication means 14 comprises a receiver 36 adapted to receive the instructions transmitted by the microcontroller 24 via a transmitter 38 of the first module. The receiver 36 is connected to a second microcontroller 40 adapted to translate the instructions received from the first module and in particular to act on a switch 42 adapted to control the connection of an electrical appliance 44 to its power source when the instruction received from the first module contains this order. Note that, according to one variant, the receiver could include a microcontroller adapted to translate the received instructions. In this variant, the microcontroller 40 is no longer necessary.

A power source 46 such as a battery, a battery, a photovoltaic cell or the network supplies the electrical energy necessary for the operation of the microcontroller 40, but can also supply the electrical power supply to the electrical apparatus 44.

According to a preferred embodiment of the invention, the communication means 14 is a wireless link in which the transmitter 38 is a radio transmitter and the receiver 36 is a radio receiver as shown schematically in Figure 1. In this case , in the first module, the power source 26 is also used as the power source of the transmitter 38. It is the same power source 46 of the second module which is also used as a power source of the receiver 36 Note that because the capacitive detector 16 consumes very little and the wireless link is activated only briefly, the energy source to be put in place in the first module is very small and easily integrable into the box containing the module. As for the power source of the second module, it can be integrated in the electrical apparatus 44 or in its immediate vicinity, for example in the false ceiling if the electrical appliance is a ceiling light fixture.

In an alternative embodiment of the wireless embodiment, one option is to use as transmitter 38 and receiver 36, transceivers called "tranceivers" which make it possible to secure the communication by well-known techniques of asynchronous acquisition of data, new attempts in case of failure, etc.

In addition, the wireless embodiment is interesting insofar as it causes a great reduction of the necessary wiring and especially a significant flexibility in the positioning of the controlled devices. In addition, the evolution of a configuration is possible without work since the various components are associable or dissociable easily and freely.

With reference to FIG. 2, the capacitive detector 16 is on a printed circuit board and comprises a first electrode 48 and a second electrode 50. In the preferred embodiment, the first electrode 48 is a solid circle made of metal, usually copper with a diameter of about 2 cm. The second electrode 50 is a wire, preferably copper, surrounding the first electrode and concentric thereto. The two electrodes are connected to the microcontroller 24 by the outputs 18 and 20. The assembly ^"of the two electrodes is inside of a metal frame 51, preferably made of copper. The frame 51 has the function of delimiting the capacitive field due to the capacitance formed by the two electrodes in the plane of the map and make this field perpendicular to the plane of the map so that this field is disturbed by the approach of the hand 34 near the wall 32. Given the frame 51 and the environment, the capacity formed by the two electrodes 48 and 50 has a value C _x generally between 10 pF and 25 pF.

When an operator or any person wishes to operate the electrical apparatus 44, he approaches his hand 34 or any other part of the body in front of the wall 32 behind which has been placed the first module 10 at a distance from the wall of between 2 cm and 5 cm. This has the effect of introducing a capacitance C _c between the electrode 50 and the frame 51. As a result, the value of the capacitance detected by the microcontroller 16 on the outputs 18 and 20 changes value, which allows the microcontroller 16 sending a control signal on the communication means 14.

As already mentioned, the frame surrounding the capacitive detector is of great importance. It may have a non-rectangular shape as the frame 51-1 which is illustrated in Figure 3. It is therefore advisable to determine the shape of this frame as accurately as possible by experience and know-how.

FIG. 4 shows the means used for the detection of the hand 34 in front of the wall 32. As can be seen, a switch 53 is connected to the output 18 of the capacitor C _x and makes the contact at a switching frequency F _s alternately with a voltage V _r and a reference capacitance C _r on the output 22. This frequency, also called charge transfer frequency, of a value of approximately 100 kHz, makes it possible to charge the capacitor C _x from the voltage V _r and load the capacity C _r from the capacitance C _x until the value reached which corresponds to the reference voltage V _r is approximately 35 nF. Assuming that N _r flaw contacts of the switch 53 with the output 22 to achieve the desired reference capacitor Cr, the latter therefore has a value equal to N _r .C _x.

When the hand 34 is approached in front of the wall 32, this has the effect of introducing a capacitance C _c of a value of approximately 0.3 pF and thus of reducing the number N _r of contacts necessary to reach the value C _r . The microcontroller 24 thus detects a lower number N _r and sends an instruction to the communication means 14 to control the connection of the electrical apparatus 44.

With reference to FIG. 5, the device according to the invention comprises a plurality of modules identical to the first module of FIG. 1, here three modules 10-1, 10-2 and 10-3, which communicate with the second module thanks to the means of communication 14-1. In particular each of the first modules 10-1, 10-2 and 10-3 comprises a capacitive detector adapted to detect the presence of the hand of a user.

The second module of FIG. 5 comprises 3 electrical appliances 52, 54 and 56 which are connected or disconnected respectively by the. Switches 58, 60 and 62. These switches are controlled by a second microcontroller 40-1 similar to the microcontroller 40 of Figure 1 which receives its instructions from one of the first modules 10-1, 10-2 or 10-3. The power supply of the components of the module and in particular the microcontroller 40-1 and electrical devices is provided by the power source 46-1, a battery in general. Note that there may be only one electrical device while there are several first modules, so several capacitive sensors.

To illustrate the embodiment of FIG. 5, the switching device which comprises several first modules each comprising a capacitive detector can be used in a "device man" interface context. increases. Thus, a device may be used as a lighting dimmer for which an access point comprises two modules, therefore two capacitive detectors placed above each other in a decor comprising a downward arrow accompanied by the minus sign and a rising arrow accompanied by the plus sign. When the fixture is off or when the fixtures are off if there are multiple fixtures, the hand approach of either detector will turn on the lighting as described above. The action of passing your hand in front of the location of the detectors from bottom to top will increase the light intensity. If a pause is made at this time, the increase in light intensity will continue as long as this proximity is maintained, this up to the maximum of the luminous intensity. Reciprocally, the light intensity can be decreased by passing the hand up and down. What has just been said can, of course, be extended to more than two associated devices.

The instructions from one of the microcontrollers of the modules 10-1, 10-2 or 10-3, in particular instructions for controlling one of the switches 58, 60 or 62 to connect or disconnect one of the electrical devices 52, 54 or 56, are received by the receiver 38-1 which transmits them to the microcontroller 40-1. Thus, bringing the hand of the operator in front of the wall where one of the modules 10-1, 10-2 or 10-3 is located causes the transmission of instructions for respectively controlling the connection or the disconnection of a electrical apparatus 52, 54 or 56.

The switching device according to the invention described above has many advantages. Indeed, it can replace all kinds of electromechanical switches usually used for lighting, heating, opening of doors, etc. This is particularly useful in public institutions of in order to prevent the public from touching the switch and thereby causing its degradation. Public institutions where the switching device according to the invention finds its place are hospitals where it is necessary to avoid contact at all costs to not transmit nosocomial diseases.

An important advantage lies in the fact that the device is placed behind a wall and thus can not be seen and does not emerge from the wall as a conventional switch. In addition, the wall which is, in general, a wall or a wall of a few centimeters thick, can be of any material such as wood, concrete, but also metal in whole or part of the partition. The position of the device may be marked by a discrete marking which may be a label, a printed mark, an engraving or any other means of identification.

The fact that the wall behind which the device can be made of metal has a considerable advantage in the hospital environment. Indeed, it has long been known that copper is an antibacterial metal. Hospitals are now installing copper cladding on the walls. Therefore, devices according to the invention can be placed without difficulty behind the walls of hospitals with such copper coatings to replace conventional switches.

Claims

A switching device adapted to be secured behind an opaque wall (32) so as not to be visible from outside said wall and for controlling the connection of at least one electrical apparatus (44) and comprising at least a first module (10) connected by a communication means (14) to a second module (12) adapted to make the connection between said electrical apparatus and a power source, said first module comprising a capacitive detector (16) adapted to change value when the hand (34) or any other part of the body of an outside user is placed near the wall where the device is fixed,

said device being characterized in that said capacitive detector which is on a printed circuit board comprises a capacitance C _x having a first metal electrode (48) consisting of a solid circle and a second electrode (50) of surrounding metal said first electrode and being concentric thereto, all of the two electrodes being included in a metal frame (51) whose function is to delimit the capacitive field due to the capacitance formed by the two electrodes in the plane of the map and make this field perpendicular to the plane of the map.

2. Device according to claim 1, wherein said capacitive detector (16) contains a means for calculating the number of times N _r that it is necessary to apply a reference voltage V _r to said capacitance C _x so that it can charge a reference capacity C _r at a predetermined value.

The device of claim 2, wherein said capacitance C _x has a value between 10 pF and 25 pF.

The device of claim 3, wherein said capacitance C _r has a value of about 35 nF.

5. Device according to one of claims 2, 3 or 4, wherein said first module (10) comprises a first microcontroller (24) adapted to transmit instructions to a second microcontroller (40) in said second module (12) for controlling the connection of said electrical apparatus (44) to its power source when said reference number N _r has it has been reduced because a parasitic capacitance C _c due to the approach of the hand of the user (34) is added in parallel to said reference capacitance C _r .

The device of claim 5, wherein said capacitance C _r has a value of about 0.3 pF.

7. Device according to one of claims 1 to 6, wherein said communication means (14) is a wireless link between a radio transmitter (38) in said first module (10) and a radio receiver (36) in said second module (12).

8. Device according to one of claims 1 to 7, comprising a plurality of modules identical to said first module (10-1, 10-2 and 10-3) each having a capacitive detector, which communicate with a second module through the means 14-1, said second module being adapted to perform the connection or disconnection of at least one electrical apparatus (52, 54 and 56) by the intermediate switches (58, 60 and 62) controlled by a second microcontroller (40-1).

The apparatus of claim 8, wherein said plurality of modules is used as a lighting dimmer by passing the hand (34) in front of said wall (32) so as to activate at least two capacitive sensors, from bottom to top to obtain an increase in light intensity and from top to bottom to obtain a decrease in light intensity.

10. Device according to one of claims 1 to 9, wherein said wall (32) is metal.

11. Device according to claim 10, wherein said metal is copper.