WO2017009279A1

WO2017009279A1 - Contactless switch intended to replace a visible contact switch

Info

Publication number: WO2017009279A1
Application number: PCT/EP2016/066413
Authority: WO
Inventors: Roberto Airoldi
Original assignee: Roberto Airoldi
Priority date: 2015-07-10
Filing date: 2016-07-11
Publication date: 2017-01-19
Also published as: FR3040107B1; ZA201802877B; FR3040107A1

Abstract

A switch suitable for being attached behind an opaque wall in such a way as to not be visible from outside the wall and intended to control the connection of at least one electric device (26). The switch is intended to replace a conventional electromechanical switch or circuit breaker comprising only the single phase wire (28), and comprises an electrical supply means (34) providing constant DC voltage used for powering the switch and a switching member (32) connected to the phase wire and to the electric device (26) in such a way as to switch the supply of the electric device, the switching member being designed to recover electrical energy with the aim of providing same to the electrical supply means when the electric device is not connected.

Description

Non-contact switch to replace a visible contact switch Technical field

The present invention relates to the control of connection and disconnection of electrical devices of all kinds, including the lighting lamps in care facilities, and particularly relates to an invisible and non-contact switch to replace a conventional switch visible contact.

State of the art

The control of connection and disconnection of electrical devices such as lighting lamps is usually carried out by means of electromechanical switches such as buttons, switches or joysticks connected to electrical devices in general by wired wiring.

However, these switches 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 switches 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 the patent application PCT / FR2015 / 000007 which relates to an invisible and contactless switching device adapted to be fixed behind an opaque wall so as not to be visible from outside the wall and intended to control the connection between an electrical device and a power source. The device includes a capacitive sensor adapted to change value when the hand or other body part of an outside user is placed near the wall where the device is attached.

This type of invisible contactless switch is therefore called to replace conventional contact and visible switches. But, the vast majority of conventional electromechanical type switches are based on the cutting of a single wire, the phase wire, which is the only one brought into the switch. If it is desired to replace this switch with a non-contact switch that requires a two-wire power supply, it is necessary to draw an additional neutral wire, which is not always easy and has a significant cost. In addition, a non-contact switch of first generation is bulky and must be housed in two juxtaposed mounting boxes, which requires a masonry recovery to add a flush-mounted box.

Another solution is to provide the use of an accumulator or a rechargeable battery to ensure the power supply of the contactless switch. Unfortunately, to make it as unobtrusive as possible and even invisible, the switch must be flush, making it almost impossible to change the battery when it is discharged.

Presentation of the invention

The main object of the invention is therefore to provide a contactless switch or switch for switching

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whose power is recovered j. GI ^~ lG -TCj ^" 1 S S1_ -T 1G C01_ - A1T11 C 1 J-TC1_ 1int of l ^~ ls 1G d.1s ^~ pO S 111 f electric.

Another more specific object of the invention is to provide a non-contact switch of the above type for switching a low-power electric lamp and using an accumulator or a rechargeable battery to provide the electrical energy necessary for its operation. .

The main object of the invention is therefore a switch adapted to be fixed behind an opaque wall of any material such as wood, concrete or metal, so as not to be visible from outside the wall and for controlling the connection of at least one electrical device. The switch makes the connection between the electrical device and a power source including a charge variation device adapted to change value when the hand or other body part of an outside user is placed near the device. the wall where the electrical device is attached. The switch is adapted to replace a conventional electromechanical switch or switch having only the single phase wire, and includes power supply means providing a constant DC voltage used for powering the switch and a connected switching member of the switch. a part to the phase wire and secondly to the power supply means, the switching member comprising means for switching the power supply of the electrical device and means for recovering electrical energy in order to supply it to the power supply means when the electrical device is not connected.

A second subject of the invention is a switch as above in which the charge variation device is placed on a card and comprises a capacitance C _x comprising a first electrode consisting of a solid circle and a second electrode surrounding the first electrode. electrode and being concentric thereto, all of the 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 card.

Brief description of the figures

1 'invention will appear more clearly on reading the following description made with reference to the drawings in which:

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C3.p3.Cltl 1 used in the switch according to the invention;

FIG. 2 is a schematic representation of the loading of the reference capacitor in the detector

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FIG. 3 is a schematic block diagram showing all the components of the switch according to the invention;

FIG. 4 is a detailed circuit of the switching element according to a first embodiment of the switch according to the invention, and

-] i in Q] i Ti latter yen iv Hpf 3 i 1 p HP Ί Ί 'ΤΤΤ ΤΊΡ ^1H ^ p> switching according to a second embodiment of the switch according to the invention.

Detailed description of the invention

Before describing the switch as a whole, it is necessary to describe the load variation device which is an important element of the invention.

With reference to FIG. 1, the load variation device 10 (see FIG. 3) is on a printed circuit board and comprises a first electrode 12 and a second electrode 14. In the preferred embodiment, the first electrode 12 is a full circle electrically conductive material such as metal, usually copper, with a diameter of about 2 cm. The second electrode 14 is an electrically conductive wire, made of metal such as copper preferably, surrounding the first electrode and concentric with it. The two electrodes are connected to a microcontroller by the outputs 16 and 18. The set of two electrodes is inside a frame 20 made of an electrically conductive material such as copper. The function of the frame 20 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 card so that this field is disturbed by the approach of the hand near the wall, a partition or a wall, behind which is the switch. Note that this wall is made of any material such as wood, concrete or even metal such as copper. Given the frame 20 and the environment, the capacity formed by the two electrodes 12 and 14 has a value C _x generally between 10 pF and 25 pF.

When an operator or any person wishes to connect or disconnect the electrical device whose connection depends on the switch, he approaches his hand or any other part of the body in front of the wall at a distance from the wall of between 2 cm and 5 cm. This has the effect of introducing a capacitance _Cc between 1 ^x electrode 14 and the frame 20. As a result, the value of the capacitance detected on the outputs 16 and 18 changes value, which allows the microcontroller to send a signal control.

Figure 2 shows the preferred means for detecting the hand in front of the wall behind which the switch is located. As can be seen, a switch 22 is connected to the output 18 of the capacitor C _x and makes contact at a switching frequency F _s alternately with a voltage V _r and a reference capacitor C _r on the output 24. This frequency , still called transfer frequency charge, a value of about 100 kHz, enables the capacitance C _x to be loaded from the voltage V _r and to charge the capacitor C _r from the capacitor C _x until the value reached which corresponds to the reference voltage V _r of about 35 nF. Assuming that N _r flaw contacts of the switch 22 with the output 24 to achieve the desired reference capacitor Cr, the latter therefore has a value equal to N _r .C _x.

When the hand is approached in front of the wall, it introduces a capacitance C _c of a value of approximately 0.3 pF and thus causes the reduction in the number N _r of contacts necessary to reach the value C _r . The microcontroller thus detects a lower number N _r and sends an instruction for controlling the connection of the electrical device.

The switch according to the invention is now described with reference to FIG. 3. This switch is therefore intended to connect or disconnect an electrical device 26 and is intended to replace a conventional switch that cuts only the wire. phase of the mains supply. As seen in the figure, it is connected on the one hand to the phase P, and is connected, on the other hand, to the output called 30 phase return which is directly connected to the electrical device 26. The latter is connected in addition to the neutral N of the mains supply. Note that the electric device 26 is generally an electric lamp.

An essential element of the invention is the switching member 32 connected to the phase P of the mains power supply by the wire 28. This switching element described in more detail subsequently, has mainly the function of recovering electrical energy necessary for the operation of the switch when the electrical device 26 is disconnected.

The switching member 32 is connected to a supply means 12 volts DC 34 needed to supply all the control electronics. Its essential function is therefore to collect the electrical energy supplied by the switching member 32 and to transform it into a positive DC voltage. For this, the power supply means 34 preferably comprises a 12 volt zener diode, but it goes without saying that any other DC voltage transformation means could be used.

An important element of the invention is the indispensable filtering means. Thus, the power supply means 34 is connected to a power filtering means 36 which comprises a plurality of filters whose function is to overcome the disturbances related to the switching device such as a common mode filter making it possible to suppress a large number of Conducted parasites and a T filter to suppress high frequency noise.

The power filtering means 36 is followed by a power-on delay timer 38 whose function is to delay by a few ms the establishment of the voltage 12 volts so as to eliminate the harmful effects of disturbances from the network.

The power-on timer 38 is connected to a power regulator 40 whose function is to provide a regulated 5-volt supply voltage to power the microcontroller 42 directly connected thereto.

Finally, the microcontroller 42 is connected to the charge variation device 10 by an electrode filtering means 44. This filtering means serves to eliminate the disturbances due to the proximity of the switching member 32 described with reference to FIGS. and 5. The filtering means is composed of a common mode filter in series with the electrodes for suppressing the conducted noise and two ferrites in series to suppress the high frequency noise. FIG. 4 shows a first embodiment of the switching member 32. As mentioned above, it is essential to recover the electric current necessary for the operation of the switch when the electrical device 26 is disconnected.

An essential element of the switching member 32 is a triac 46 which has a switch function for the alternating current, ie it ensures the connection of the electric device 26 when it is actuated and its disconnection when 'it's off. Note that the line 30 is called phase return because it becomes the phase when the electrical device 26 is connected, but it plays the role of neutral when the electrical device 26 is disconnected.

When the Triac 46 is not actuated, this means that the electrical device 26 is disconnected, the voltage of 230 volts established between the phase of the sector on the line 28 and the neutral on the line 30 allows the capacitor 48 extracting non-continuous samples that are routed via the resistor 50 to the diodes 51 and 52. The diode 51 allows the transmission of negative alternation current samples to the diode 52 which, in turn, allows the transmission of the current samples. Positive and negative half-waves towards the supply means 34. A zener diode (not shown) in the supply means 34 makes it possible to transform the samples into a positive voltage of 12 volts necessary for the operation of the switch.

When the microcontroller 42 sends a connection command of the electrical device 26 because there has been detection of the user's hand in front of the wall behind which the switch is located, this command is transmitted to the gate of the transistor 54 by through the resistors 56 and 58, the transistor 60 and the resistor 62. This control allows the transistor 54 whose operation is stabilized by the resistor 66 to activate the coil 64. The magnetic field of the coil 64 makes it possible to close the contact of the relay 68 which then controls the activation of the Triac 46. Note that the resistor 70 makes it possible to limit the control current of the Triac 46 which is biased at 12 volts when relay 68 is closed.

A light emitting diode (LED) 72 in series with the resistor 74 allows the user to view the state of the switch. Thus, the LED 72 being on when the electrical device 26 is not connected, it makes it possible to identify the location of the switch in a corridor without light.

A second embodiment is now described with reference to FIG. 5. This embodiment applies when the electrical device 26 is an LED which is a low power lamp of about 6 watts which consumes 30 mA. For this type of lamp, it is necessary to interrupt any current in the lamp to extinguish it. Therefore,

It is impossible to take electrical energy during the time when the lamp is off.

When the electrical device 26 is connected, that is to say that the LED lamp is lit in this case, a transformer 76 converts the AC voltage of the sector into a 12 volt AC voltage which is converted into DC voltage by a rectifier. Diode bridge 78. This 12 volts DC voltage allows the charging of the rechargeable battery or accumulator 80. The accumulated electrical energy is fed to the supply means 34 via the resistor 82 which limits the current drawn. Therefore, during the time when the lamp 26 is not powered, the switch has a voltage of

12 volts continues for operation.

The switch circuits used for the lamp connection control are the same as in the first embodiment. However, note a difference. Indeed, when the microcontroller controls the connection of the lamp, the contact of relay 84 controlled by the coil 64 makes it possible to directly switch between the lines 28 and 30 and thus to make the connection of the lamp 26.

Note that the load variation device described here is a capacitive detector, but that it is possible to use another type of charge variation device such as for example a device in which the load subjected to variation consists of an electromagnetic wave receiver.

The switch 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 so that the public does not have to touch the switch and thus cause 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.

Another advantage of the invention is that the switch according to the invention has a small footprint because the control is entirely electronic. It fits easily into a standard flush-mount box with a diameter of approximately 60mm.

Claims

1. Switch adapted to be fixed behind an opaque wall of any material such as wood, concrete or metal, so as not to be visible from outside said wall and intended to control the connection of at least one electrical device (26), said switch adapted to effect the connection between said electrical device and a power supply source comprising a charge variation device (10) 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 fixed,

said switch being characterized in that it is adapted to replace a conventional electromechanical switch or switch having only the single phase wire (28), and in that it comprises a power supply means providing a constant DC voltage used for the power supply of said switch and a switching member (32) connected on the one hand to said phase wire and on the other hand to said power supply means, the switching member comprising means for switching the power supply of the device and means for recovering electrical energy for the purpose of supplying it to the power supply means when the electrical device is not connected.

The switch of claim 1, wherein said charge variation device (10) is placed on a board and includes a capacitance C _x having a first electrode

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(14) surrounding said first electrode and being concentric

a conductive frame (20) 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 card.

The switch according to claim 1 or 2, wherein said switching member (32) comprises a triac (46) which connects the electrical device (26) when actuated and disconnects when turned off, the connection / disconnection of said electrical device being controlled by a microcontroller (42) when the hand of the user is detected in front of the wall behind which the switch is located by said charge variation device (10).

The switch according to claim 3, wherein said means of said switching member (32) for recovering electrical energy comprises a capacitance (48) for extracting non-continuous samples which are transmitted to suitable diodes (51, 52). for transmitting the positive and negative half-wave samples to a zener diode adapted to transform said samples into a positive voltage of 12 volts necessary for operation of the switch.

5. Switch according to claim 1 or 2, wherein the electrical device (26) is a low power lamp such as an LED with a power of about 6 watts, for which it is necessary to interrupt any current in the lamp to extinguish it, and said switching member (32) comprises a transformer (76) transforming the AC voltage of the sector into an AC voltage of 12 volts, said voltage being converted into DC voltage by a diode bridge rectifier ( 78) which charges a battery or a rechargeable battery (80), which allows the switch to have a 12 volts DC voltage when the electrical device is not connected.

6. Switch according to one of claims 1 to 5, further comprising a power filtering means (36) which comprises a plurality of filters whose function is to overcome the disturbances related to the switch, including a common mode filter for remove a large number of conducted parasites and a T filter to suppress high frequency noise.

7. Switch according to one of claims 1 to 6, further comprising a power-on delay (38) whose function is to delay a few ms the establishment of the voltage 12 volts so as to eliminate the adverse effects of disturbances from the network.

8. Switch according to one of claims 1 to 7, further comprising an electrode filter means (44) directly connected to the load variation device (10) for suppressing disturbances due to its proximity, said filtering means being composed a common mode filter in series with said charge variation device for suppressing the duct noise and two ferrites in series to suppress the high frequency noise.

9. Switch according to one of claims 1 to 8, wherein said switching member comprises an LED (72) which is lit when said electrical device (26) is not connected, which allows to identify the location of the switch in the absence of light.