Modular electrical appliances and housing comprising same

Information

  • Patent Grant
  • 6664468
  • Patent Number
    6,664,468
  • Date Filed
    Thursday, December 27, 2001
    23 years ago
  • Date Issued
    Tuesday, December 16, 2003
    21 years ago
Abstract
A housing (1) designed to contain an assembly of modular electrical appliances mounted on a support (12, 14), whereof at least the first modular electrical appliance provided with data transmitters (36) and at least a second modular electrical comprising data receivers (42) enabling wireless communication from the first appliance to the second appliance. When the modular appliances are mounted in operating position, the data transmitters (36) of the first appliance are oriented opposite a surface of walls (2-8) of the housing. The data receivers can also be oriented opposite a wall surface of the housing.
Description




SUMMARY OF THE INVENTION




Given the above problems of the prior art, the present invention proposes a housing containing a set of modular electrical devices mounted on supports and including at least one first modular electrical device provided with data sender means and at least one second modular electrical device including data receiver means, enabling wireless link communication from the first device to the second device. When the modular electrical devices are mounted in their operating position, the data sender means of the first device face a surface of walls of the housing.




It is therefore clear that the path of the signals from the sender means to the receiver means entails at least one reflection from at least one inside wall of the housing.




The application has discovered, surprisingly, that the signal sent does not have to be conveyed along a specified path to the receiver means of another module because the inside walls of the housing provide an adequate reflector for distributing the beams.




When the modular electrical devices are mounted in their operating position, the data receiver means of the second device advantageously also face a surface of the walls of the housing.




The wireless link can be an infra-red link. It can be provided by one or more light-emitting diodes (LED) and receiver photodiodes routinely used in the field of remote controllers.




It has been found that with this arrangement the inside walls of the housing


1


—and especially that of the back


2


—act as a sufficiently effective reflector to distribute a beam coming from a sending device to the receiver means of all the other devices in the housing, whether the latter are on the same rail or on another rail.




In a preferred embodiment of the invention, in which the housing has at least one part providing access to the interior and in that, when they are in their operating position, the data sender means and the data receiver means face surfaces of walls that are not in said part providing access to the interior. In this way, it is possible to provide the normal links between the modular electrical devices even when the housing is “open”. A portion providing access to the interior can be a door, a cover plate, an access hatch or any other equivalent device.




When the modular electrical devices are in their operating position, the data sender means and the data receiver means preferably face the same inside face of the housing.




When the modular electrical devices are in their operating position, the data sender means and the data receiver means are advantageously oriented to obtain an internal reflection at the surface opposite said part providing access to the interior.




The housing can be equipped with support means, for example rails


14


as described with reference to

FIG. 1

, for removably fixing said first and second modular electrical devices in a plane and in an arbitrary manner, a first modular electrical device being able to transmit to at least one second modular electrical device at any location in said plane.




The invention provides the considerable advantage of being able to place the modular electrical devices at the locations most propitious to their respective function without worrying about providing a wired or wireless link that must comply with a specified alignment.




The invention also relates to a modular electrical device specifically intended for the aforementioned housing and having on the same face means for mounting it in said housing and wireless data sender and/or receiver means.




The invention finally provides a modular electrical device specifically intended for the aforementioned housing and having wireless data sender and/or receiver means on the top or bottom face.











BRIEF DESCRIPTION OF THE DRAWINGS




Other advantages and features of the invention will become more clearly apparent on reading the following description of a preferred embodiment of the invention, which description is given by way of non-limiting example only and with reference to the accompanying drawings, in which:





FIG. 1

, already described, is a diagrammatic view of a housing in which modular electrical devices can be mounted;





FIG. 2

is a diagrammatic side view of two modular electrical devices in accordance with the present invention mounted on their support;





FIG. 3

is a diagrammatic partial side view of another set of modular electrical devices mounted in the

FIG. 1

housing, in which view the path of some infra-red rays is shown;





FIG. 4

is a front view of this set of modular electrical devices; and





FIG. 5

is a perspective view of a different embodiment of the housing.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




In the following description, the term “front” refers to parts and faces that face toward the door


10


and the term “rear” refers to parts and faces that face toward the back


2


of the housing (see FIG.


1


).





FIG. 2

is a simplified view of two modular electrical devices


30


-


1


and


30


-


2


, referred to hereinafter as “modules”, providing wireless data transmission in accordance with the present invention. In the conventional way, each module


30


-


1


and


30


-


2


has on its rear part


30




a


a cavity


32


for mounting it on a rail


14


inside the housing


1


. The front face


30




b


of the module has a part


30




c


forming its “nose”. The nose


30




c


carries interface means


34


accessible when the door


10


is open. The interface means


34


can consist of control buttons, indicators, display devices, etc.




The module


30


-


1


has on its rear face


30




a


, facing toward the back wall


2


, a light-emitting diode


36


for emitting infra-red signals to other modules. The signals come from a central unit


38


which controls all functions of the module


30


-


1


and are sent to a data transmitter unit


40


. The latter converts the data to be transmitted from the central unit


38


into control signals in the form of electrical pulses in accordance with a predetermined code. Those pulses are transmitted to the diode


36


, which emits infra-red signals corresponding to the data.




The technique of transmitting commands via a light-emitting diode is well known in itself and for conciseness is not described here.




The diode


36


is on the rear face


30




a


of the module, at a short distance, of the order of 10 to 50 mm, from the back wall


2


of the housing, so that the infra-red beam emitted is diffused over a portion of the surface of the back wall


2


. Note that a light-emitting diode


36


generally emits omnidirectionally, and therefore some rays may also reach other walls


4


to


8


of the housing, and in particular the side walls


4




a


to


4




b.






Each light-emitting diode


36


can be associated with an optic (not shown) enabling it to diffuse over a very wide range of angles, in order to improve the distribution of the signals sent to the walls


2


to


8


of the housing


1


.




The module


30


-


2


has on its rear face


30




a


receiver means in the form of one or more photodiodes


42


. The photodiode


42


is turned to the light-emitting diode


36


of the module


30


-


1


in order to be able to detect its signals. The photodiode


42


is connected to a data receiver unit


37


in turn connected to the central unit


36


in order to transmit thereto the various signals received.




The photodiodes


42


are advantageously mounted on a well exposed part of the rear face


30




a


of the module to receive signals emanating at various angles from the walls


2


to


8


of the housing


1


. The photodiodes


42


are preferably mounted outside shadow areas that may be created by the supports on which the modules


30


-


1


and


30


-


2


are mounted.




The photodiodes


42


can be associated with optics (not shown) enabling them to capture radiation over a very wide range of angles.





FIG. 3

is a diagrammatic partial view of another set of modules including, in addition to the modules


30


-


1


and


30


-


2


, a combined sender/receiver module


30


-


3


, its central unit being connected both to a data transmitter unit connected to the diode


36


and to a data receiver unit connected to the diode


42


. In this example, three modules are mounted one under the other in the housing


1


. Other similar modules that can be seen in

FIG. 4

are also mounted below and beside those shown.




The rays (shown in dashed line in

FIG. 3

) directed onto the walls


2


to


8


by the light-emitting diodes


36


are reflected in all directions, especially by the back wall


2


, but also by the side walls


4




a


and


4




b


, and partly by the top


8


and the base


6


if these are also reflective.




In the example shown in

FIGS. 3 and 4

, only the modules


30


-


1


and


30


-


3


are equipped with sending means, in this example the light-emitting diode


36


. On the other hand, only the modules


30


-


2


and


30


-


3


are equipped with receiver means


42


like those described above. In other words, the module


30


-


1


is a sender module, i.e. a “master” module, the module


30


-


3


is merely a receiver module, i.e. a “slave” module, and the module


30


-


3


is a combined module.




If one of the master sender modules


30


-


1


or


30


-


3


must transmit, its light-emitting diode


36


is activated under the control of the circuits


38


and


40


and in accordance with a particular protocol. The infra-red signals emitted undergo multiple reflections against the walls


2


to


8


of the housing so that all the rear faces


30




a


—and therefore all the photodiodes


42


—of all the modules in the housing


1


receive the signal sent, with adequate intensity. In this way the photodiode


42


of all the modules in the housing


1


can detect and decode a message coming from another module emitted by a light-emitting diode


36


. Note that the light-emitting diodes and/or the photodiodes being oriented toward the wall


2


of the housing


1


, the door


10


(or other equivalent access means) can remain open without impeding the transmission of signals. The door


10


has its back to the light-emitting diodes


36


and the photodiodes


42


and therefore hardly contributes at all to the retransmission of signals.




In practice, if the housing is made of metal, the inside surfaces of the walls are sufficiently reflective to achieve a good distribution of the signals (which are infra-red signals in this instance) over the whole of the space occupied by the modules.




The same applies to housings made of plastics materials and most other materials used in this art. If necessary, a reflective coating can be provided on the inside face of at least one wall, in particular the back wall


2


. The coating can take the form of a reflective panel against the wall or walls concerned, for example, or a reflective layer applied to it or them.




A sender module


30


-


1


or


30


-


3


can transmit a message to all the modules or to one of them or to a group of them. The transmission protocols enabling this selective transmission are well known and are therefore not described in detail. For example, each module can have its own address and the sender module initially transmits an address or a series of addresses followed by a message to be sent to those addresses. The message can be a command to actuate various devices internal to the modules, such as switches or indicator lamps, or a signal conveying information necessary for the operation of the module or modules concerned.




The signals coming from a sender module


30


-


1


or


30


-


2


are captured by the photodiodes


42


of the modules


30


-


2


and


30


-


3


. Depending on the addresses detected, each module can determine if the message transmitted concerns it or not.




Because it is only a receiver, the module


30


-


2


cannot transmit acknowledgement messages. As a general rule, slave modules are simple devices. Likewise the module


30


-


1


, which cannot receive acknowledgement messages. The invention does not require each module also to serve as a repeater, as in the case of some prior art systems. These simple devices (switches, relays, etc.) can therefore be inexpensive.




For example:




the sender means can be a diode emitting at a wavelength of 950 nanometers (nm), at a power of 40 milliwatts per steradian (mW/sr) within an emission angle from 90° to 150°, for example 120°, as shown in

FIG. 3

, emission being pulsed to maximize the range with acceptable power; and




the receiver means can be a diode with built-in amplification and having high immunity to ambient light, tuned to the same frequency (950 nm) and having a sensitivity from 0.2 to 0.4 milliwatt per square meter (mW/m


2


), in this example 0.3 mW/m


2


.




Note that, thanks to the invention, the positions of the modules relative to each other do not affect the possibilities of communication, whether the modules are on the same rail


14


or not. Modules can therefore be moved, rearranged, removed or added without requiring any rewiring or other measures to ensure module-to-module continuity for relaying messages.




In the embodiment shown in

FIG. 5

, the housing is a cabinet


12


including a chassis


21


fixed to a wall


22


and a lid


23


fixed to the chassis


21


, which includes two rails


24


similar to the rails


14


of the housing


1


.




In this embodiment, the reflections occur directly at the wall


22


, but if that wall is not sufficiently reflective, an appropriate plate can be fitted to it, for example a plate with apertures.




In an embodiment that is not shown, the diode or diodes is/are on the top or bottom face of the modules, not on the rear face.




Clearly the invention lends itself to many other embodiments that will be evident to the skilled person, whether this concerns the structure on which the modules are mounted, the transmission protocols or the technology of the sender and receiver means.



Claims
  • 1. A housing containing plural electrical devices mounted don supports,the housing having interior surfaces, a first of the plural electrical devices having a data sending light emitting diode transmitting an infra-red signal, and a second of the plural electrical devices having a data receiving photodiode receiving the infra-red signal transmitted by the data sending light emitting diode, wherein the data sending light emitting diode faces one of the interior surfaces of the housing.
  • 2. The housing of claim 1, wherein the data receiving photodiode faces one of the interior surfaces of the housing.
  • 3. The housing of claim 2, wherein the data receiving photodiode and the data sending light emitting diode face a same one of the interior surfaces.
  • 4. The housing of claim 1, wherein the housing includes a door providing access to the electrical devices and wherein the door is not the one interior surface faced by the data sending light emitting diode.
  • 5. The housing of claim 4, wherein the data receiving photodiode and the data sending light emitting diode face one of the interior surfaces opposite the door.
  • 6. The housing of claim 1, further comprising a support that removably fixes the first and second electrical devices in a plane, and wherein the data sending light emitting diode transmits the infra-red signal to the data receiving photodiode by reflecting the infra-red signal from the one of the interior surfaces of the housing.
  • 7. The housing of claim 1, wherein the data sending light emitting diode emits the infra-red signal with an emission angle of 90° to 150°.
  • 8. The housing of claim 1, wherein the first of the electrical devices does not include the data receiving photodiode.
  • 9. The housing of claim 1, wherein the second of the electrical devices does not include the data sending light emitting diode.
  • 10. The housing of claim 1, wherein the photodiode has a sensitivity of 0.2 to 0.4 mW/m2.
  • 11. A housing containing plural electrical devices mounted on supports,the housing having interior surfaces, a first of the plural electrical devices having data sending means for transmitting an infra-red signal, and a second of the plural electrical devices having data receiving means for receiving the infra-red signal transmitted by the data sending means, wherein the data sending means faces one of the interior surfaces of the housing, and wherein at least one of the first and second electrical devices has a face that includes (a) means for mounting the device in the housing and (b) at least of the data sending means and the data receiving means.
  • 12. The housing of claim 11, wherein the face is a rear face of the at least one of the first and second electrical devices.
  • 13. The housing of claim 11, wherein the face is one of a top and a bottom face of the at least one of the first and second electrical devices.
  • 14. A housing containing plural electrical devices that communicate with each other,the housing comprising a generally flat interior surface that reflects infra-red signals and a support for the electrical devices, the support being spaced from the interior surface to leave a gap between the interior surface and the electrical devices mounted on the support, a first of the plural electrical devices being mounted on the support and comprising an infra-red signal transmitter that faces into the gap and transmits infra-red signals toward the interior surface of the housing, and a second of the plural electrical devices being mounted on the support and comprising an infra-red signal receiver that faces into the gap and receives the infra-red signals from the infra-red signal transmitter that have been reflected from the interior surface of the housing, wherein the first electrical device has a surface that is removably fixed to the support and on which the infra-red signal transmitter is mounted.
  • 15. The housing of claim 14, wherein the interior surface is a rear wall of the housing.
  • 16. The housing of claim 14, wherein some of the plural electrical devices are arranged in a group that includes one of the first electrical devices and plural ones of the second electrical devices.
  • 17. The housing of claim 16, wherein the one of the first electrical devices in the group further comprises an infra-red signal receiver for receiving an infra-red signal from another one of the first electrical devices not in the group.
  • 18. The housing of claim 1, wherein the first electrical device has a surface that is removably fixed to a support and on which the data sending light emitting diode is mounted.
Priority Claims (1)
Number Date Country Kind
00 01198 Jan 2000 FR
BACKGROUND OF THE INVENTION

The present invention relates to modular electrical devices and more particularly to devices which are grouped in a common housing and which need to communicate with each other. In the present context the term “housing” refers to any kind of case, cabinet or other enclosure able to integrate a plurality of modular electrical devices. The modular electrical devices can have many different functions in a domestic or industrial electrical installation. Examples include control stations, circuit-breakers, relays, meters, switches, etc. In the case of some such devices, it is necessary for at least one of them to be able to communicate data to at least one other modular electrical device. This is the case, for example, if the housing includes a centralized control device for actuating various functions of the various modular electrical devices in the housing, depending on the time of day, power distribution conditions or any other parameters. To this end, at least some of the modular electrical devices must exchange data. The data is generally in the form of digital signals coded in accordance with a predefined protocol. FIG. 1 shows diagrammatically a housing 1 designed to accommodate an assembly of modular electrical devices. In this example it is a cabinet made from sheet metal or plastics material and has a back wall 2, two lateral walls 4a and 4b, a base 6, a top 8 and a door 10 facing the back wall 2 and which can completely close the cabinet 1. Depending on the configuration of the housing 1, the door 10 can be replaced by a series of doors, each enabling partial opening of the housing, or by one or more removable cover plates. Toward the back 2 of the cabinet 1 is a fixed structure forming a support for the modular electrical devices. In this example, it is made up of uprights 12 against the lateral walls 4a and 4b. A plurality of horizontal rails 14 are fixed to the uprights 12. The rails 14 are shaped to retain the modular electrical devices in a removable manner. The modular electrical devices can then be mounted arbitrarily on the structure 12, 14. In the conventional way, data is communicated between modular electrical devices by connecting cables. It is then necessary to provide, for each transmission channel, a cable that connects a port of one module to that of another module. In some applications, installing such wiring is complex. The wiring can also occupy a large space around the devices and require considerable wiring and maintenance time. Also, the cables are exposed to electrical interference, which can be at very high levels, and in some case impede or even prevent the correct transmission of information. To alleviate the above drawbacks, it has already been proposed to use wireless links for communication between the various devices, generally by means of infra-red beams. This exploits the fact that a sender of one device can be aimed directly at a receiver of another device. For example, some prior art modular electrical devices are installed side by side on the same rail. The devices have an infra-red sender on one side and a receiver on the other side. Accordingly, when they are grouped side by side, the sender of one if in direct view of the receiver of the other. In this way, infra-red information can be transmitted along a row of devices on the same rail. Depending on the application, the devices merely serve as a repeater if the information is not addressed to them. If the information is addressed to them, they execute an action. To enable messages to be sent to another rail above or below it, an optical-electrical converter is provided at the end of the rail. There is then a wired connection to an electrical-optical converter at the end of the adjacent rail. Note that this system can operate only in a compact group; in other words each device is a link in a transmission chain. Other prior art electrical devices, in particular surge arresters, employ an optical surveillance system. When the devices are mounted on their support, they conjointly form a conduit, each having a hole through it forming one section of the conduit, so that the set of components constitutes an optical tunnel. A light emitting device is provided at one end and a device for receiving that light is provided at the other end. If a fault occurs in one of the devices, means for blocking the optical conduit are activated to break the optical link. Thus absence of the optical signal at the receiver indicates that at least one of the devices is inoperative. There are also systems that use an optical signal to communicate the operating status of one or more supervised electrical devices. For example, the document WO-A-9905761 describes an overvoltage protection device equipped with an autodiagnostic unit connected by means of an opto-isolator to a communication device. Optical data can therefore be transmitted via the opto-isolator in the event of an incident and relayed to a remote point via a telecommunication line in the form of electrical signals. Note that if optical or infra-red beams are used to provide the link, they always take a linear and confined path. As a result, if several devices are to be able to communicate, they must on the one hand be equipped with signal relays and on the other hand be located on a specific optical path. These requirements constitute a constraint, especially when it is a question of installing modular electrical devices in a housing in a given configuration.

PCT Information
Filing Document Filing Date Country Kind
PCT/FR01/00282 WO 00
Publishing Document Publishing Date Country Kind
WO01/57897 8/9/2001 WO A
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Number Date Country
298 00 372 Apr 1998 DE