Patent Publication Number: US-10323837-B2

Title: Lighting system

Description:
FIELD OF THE INVENTION 
     The present invention relates to a lighting system. 
     TECHNICAL BACKGROUND 
     A lighting system which comprises a channel and lighting inserts which can be inserted into the channel is known to the applicant. In said system, a busbar is integrated into the channel. In order to connect the busbars of consecutive portions of the channel, a busbar connector is provided. In the system known to the applicant, the dimensioning takes into consideration the space requirement for controlling the lighting inserts in a wired manner via control lines by means of what is known as the DALI system. 
     However, in the case of this known solution, it is not possible to implement continuous, and in particular long, aesthetically pleasing strip lights at the same time as a low installation depth or “system height” and also a low installation width or “system width”. 
     This is a state of affairs for which there is room for improvement. 
     FIELD OF THE INVENTION 
     In this context, an idea of the invention is to provide a lighting system that can be constructed so as to be particularly slim and makes it possible to produce continuous, aesthetically pleasing strip lights having a low installation depth and a low installation width. 
     Thus, a proposal is made for a lighting system comprising at least one channel for receiving at least one light unit that can be inserted into the channel, and further comprising at least one connector that can be inserted into the channel, the channel comprising, in an inner region thereof, a busbar for supplying the light unit, which can be electrically coupled to the busbar, with power. In the lighting system according to the invention, the connector is designed to electrically couple busbar portions of the busbar to one another. Furthermore, the connector is designed to be mechanically coupled to portions of the channel. According to the invention, the channel and the connector are further designed such that, when inserted in the channel, the light unit can be arranged so as to overlap the connector, inserted into the channel in order to couple the busbar portions, within the channel. 
     The concept of the invention is that of making it possible to produce continuous strip lights, even long ones, by means of light units that can be inserted into the channel, by the channel, the connector and the light unit being designed, as components of the lighting system, such that, in an operational state, i.e. when the light unit and the connector have been inserted into the channel, the light unit and the connector can overlap one another within the channel. It is thus also possible to achieve a low “system height” and “system width”, in particular low widths and heights of the channel. At the same time, the proposed lighting system having the busbar provided in the inner region of the channel allows for versatile, multi-faceted lighting solutions; in particular, the busbar can be used to supply different kinds of lighting inserts that can be inserted into the channel, with power. 
     In one embodiment, the lighting system further comprises the at least one light unit. In this case, the channel, the light unit and the connector are designed such that, when inserted and overlapping the connector, the light unit can be received in the channel completely or at least substantially completely. A lighting system of this kind is particularly slim and discreet. A light unit that is completely received in the channel can be particularly aesthetically pleasing. 
     In a development of the invention, the light unit and the channel may be designed such that, when inserted, the light unit is arranged in the opening in the channel so as to be flush therewith. Alternatively, in a development, the light unit and the channel may be designed such that, when inserted, the light unit is offset in the inner region of the channel, in relation to the opening in the channel. Whether flush or offset, the light unit can therefore be completely received in the channel. It is possible for both the flush arrangement and the offset arrangement to be aesthetically pleasing. 
     In a further embodiment of the invention, the lighting system further comprises the at least one light unit, with the channel, the light unit and the connector being designed such that, when inserted and overlapping the connector, the light unit protrudes out of the opening in the channel. However, it is noted that, even in this case, when inserted the light unit can overlap the connector, likewise inserted in the channel, within the channel. The light unit that protrudes out of the opening in the channel makes it possible to achieve a different, aesthetic effect. 
     In particular, whether flush with the opening in the channel, offset in relation to the opening in the channel or protruding out of the opening in the channel, the light unit makes it possible to produce continuous strip lights, in particular not having poorly lit junction points. 
     According to a further embodiment of the invention, the channel and the light unit are designed such that, when inserted, the light unit substantially fills the channel in the transverse direction thereof, at least on a viewing side of said light unit. By means of a slim lighting system having a relatively low installation width, an embodiment of this kind advantageously makes it possible to achieve effective lighting. In this embodiment, the available system width is advantageously used to house the light unit. 
     In a further embodiment, the lighting system comprises at least two of the light units, which can be each arranged so as to overlap the connector within the channel such that end portions of the light units that overlap the connector substantially directly adjoin one another on the end faces thereof and in particular conceal the connector at least in part, for example substantially completely. Thus, this embodiment makes it possible to produce aesthetic, continuous strip lights, avoid unlit points in the system, and advantageously conceal the connector behind the light units. 
     In a further embodiment, the light unit is designed as a linearly elongate unit. In this case, the light unit is in particular designed to form, together with at least one further linearly elongate light unit and when inserted in the channel, a continuous strip light during operation. 
     In another embodiment, the length of the light unit in a longitudinal direction thereof is at least ten times the width of the light unit, the width being taken to be in a direction which extends transversely to a depth direction of the channel when the light unit is inserted. 
     In particular, the length of the light unit may be at least 20 times, at least 40 times, at least 60 times or at least 80 times the width of the light unit. 
     In a further embodiment, light can be emitted, during operation, by the light unit in a light outlet region that extends over substantially the entire length of the light unit. Thus, the entire length of the light unit can be used for emitting light, and dark points on the strip light are avoided. 
     According to a further embodiment, the light unit can be coupled to the channel in order to hold said light unit. The light unit can thus be held in a defined manner for the attachment thereof. In particular, the light unit can be magnetically coupled to the channel. Magnetic coupling offers a large degree of flexibility in the arrangement of the light unit in the channel. Magnetically, the light unit can also be held in a reliable manner. An operator can easily establish and release the magnetic coupling, and without tools. 
     In particular, in one embodiment, the channel may be provided with at least one ferromagnetic element in order to allow the light unit to be magnetically coupled to the channel. 
     In one embodiment of the invention, the channel is designed having at least two portions, the portions of the channel meeting at a junction point and each having a busbar portion, the connector further allowing the busbar portions to be electrically coupled across the junction point. In this case, the connector can electrically couple in particular the busbar portions of straight channel portions to one another, which adjoin one another in a straight or angled manner. For this purpose, the connector may in particular comprise contact elements, each of which can be brought into contact with a conductor of one of the busbar portions in order to electrically couple the busbar portions. 
     In one embodiment, the portions of the channel are each formed having an extruded profile body, in particular having an extruded profile made of aluminium or an aluminium alloy. 
     In embodiments of the invention, the channel may be designed as a built-in channel for being built into a wall or a ceiling, as a mounting channel, in particular for being mounted on a wall or on a ceiling, or as a channel for being mounted in a suspended manner, in particular on a ceiling. As a built-in channel, the channel may in particular be designed to be built into a plasterboard ceiling or plasterboard wall so as to be preferably edgeless and/or flush. 
     In another development of the invention, the portions of the channel may be assembled to form a channel of any desired length, the busbar portions of adjoining portions of the channel being electrically coupled by a connector in each case. The lighting system may therefore comprise a plurality of connectors as required. The proposed lighting system thus makes it possible to produce lighting solutions for spaces of all different sizes. 
     Mechanically coupling the connector to the portions of the channel also allows portions of the channel adjoining at the junction point to be additionally mechanically aligned and guided with respect to one another. Additional elements for mechanical guidance are not therefore required. Advantageously, while requiring little space, the connector both allows the busbar portions to be electrically coupled, and mechanically guides the adjoining portions of the channel. This further contributes to the lighting system, having a low installation width and a low installation high, being slim. 
     In one embodiment of the invention, the light unit comprises a light provision and optics unit and at least one power supply unit. In this case, the power supply unit comprises contact devices, which allow the light unit to be electrically coupled to the busbar. Furthermore, in this embodiment, the power supply unit is electrically coupled to the light provision and optics unit. The power supply unit further comprises a housing element that is mechanically coupled to the light provision and optics unit. Thus, a standardisation of the power supply unit for different light units can advantageously be achieved, for example. For example, different kinds of light unit may comprise an identical power supply unit, but different light provision and optics units. Furthermore, light units of different lengths in the longitudinal direction thereof could, for example, advantageously have identical power supply units; in this case, a longer light unit may comprise a plurality of identical power supply units, while short light units could each comprise only one power supply unit of this kind. Mechanically coupling the power supply unit to the light provision and optics unit by means of the housing element of said power supply unit makes it possible for the two units to be reliably connected. 
     In one embodiment, the power supply unit is latched to the light provision and optics unit. In particular, for this purpose the housing element of the power supply unit may be provided with latching devices. The power supply unit can thus be easily and reliably connected to the light provision and optics unit. The power supply unit being connected to the light provision and optics unit by means of latching devices on the housing element of the power supply unit may also be cost-effective. 
     In a further embodiment of the invention, the housing element of the power supply unit projects, in a direction which extends in parallel with a depth direction of the channel when the light unit is inserted, substantially as far beyond the light provision and optics unit as a housing of the connector extends in a thickness direction of the connector. In this way, the space available in the channel, in particular in the inner region thereof, can be utilised particularly effectively, this at the same time allowing the light unit to overlap the connector. 
     In a further embodiment, when inserted in the channel, the light unit can be arranged so as to overlap the connector, inserted into the channel in order to couple the busbar portions, such that the light provision and optics unit overlaps the connector, whereas the power supply unit does not overlap the connector. This again allows the available space to be utilised effectively. 
     In one embodiment, the light unit, in particular the light output thereof, and for example the intensity thereof, can be switched and/or controlled wirelessly. 
     In another embodiment, the light unit can be switched and/or controlled wirelessly, the power supply unit comprising, for this purpose, a module by means of which control signals for switching and/or controlling the light output of the light provision and optics unit, in particular the intensity thereof, can be received wirelessly, the module preferably being received in the housing element of the power supply unit. 
     Wirelessly controlling the light unit or wirelessly switching the light unit allows the installation depth and the installation width of the lighting system to be advantageously kept to a minimum. The ability to switch and/or control the light unit wirelessly makes it possible to circumvent the space requirements that arise when control lines are used for controlling light units in a wired manner. Space-consuming contact devices or terminals for control lines, such as for what is known as the DALI system are dispensed with, and it is thus possible for both the power supply unit and the connector to be particularly slim. 
     In particular, the control signals for switching and/or controlling the light output of the light provision and optics unit may be radio signals. 
     In a further embodiment of the invention, the power supply unit is designed as a holding unit for the light unit, for holding the light unit in the channel. In this case, in particular, the power supply unit may contain magnets, for example permanent magnets, for mechanically coupling the light unit to the channel. Thus, the function of holding the light unit irrespective of the specific embodiment of the light provision and optics unit can be built into a standardisable power supply unit. The advantages of mechanical coupling to the channel have already been explained above. Magnetic coupling by means of permanent magnets can be implemented particularly easily. 
     In particular, the housing element of the power supply unit may additionally receive the magnets. 
     In one embodiment, the extension of the light unit in a direction which is in parallel with the depth direction of the channel when the light unit is inserted is smaller than or equal to the width of the light unit in a direction transverse to the depth direction of the channel. This may again contribute to a space-saving and aesthetic design of the lighting system. 
     According to a further embodiment, in a direction which extends transversely to the depth direction of the channel when the light unit is inserted, a width of the power supply unit is at least 80%, for example at least 90%, of a width of the light provision and optics unit. In particular, in a direction which extends transversely to the depth direction of the channel when the light unit is inserted, a width of the housing element of the power supply unit may be at least 80%, for example at least 90%, of a width of the light provision and optics unit. In this way, the space available in the inner region of the channel may be utilised even more effectively, and this again has an advantageous influence on the space requirement, in particular the installation depth, for example, of the lighting system. 
     In particular, the width of the housing element of the power supply unit may correspond substantially to the width of a connector housing of the connector. 
     According to a further embodiment, in a direction which extends in parallel with a depth direction of the channel when the light unit is inserted, the light provision and optics unit has a height of from approximately 13 mm to approximately 20 mm, for example approximately 14 mm or approximately 19 mm, for example 14.1 mm or 14.3 mm or 19 mm, and/or in a direction which extends transversely to the depth direction of the channel when the light unit is inserted, the light provision and optics unit has a width of from approximately 24 mm to approximately 28 mm, for example approximately 25 mm or approximately 27 mm, for example 25.4 mm or 27.2 mm, and/or the channel comprises, at least in a region in which the light provision and optics unit is housed when the light unit is inserted, has an inner width of from approximately 27.5 mm to approximately 28.5 mm, for example substantially 28 mm. A lighting system of this kind is particularly slim and space-saving. 
     According to a further embodiment, in a direction which extends in parallel with the depth direction of the channel when the light unit is inserted, the light unit has a height, as measured over housing parts of the light unit, of from approximately 19 mm to approximately 27 mm, for example approximately 20 mm or approximately 21 mm or approximately 25 mm, for example 20.3 mm or 20.5 mm or 25.2 mm, and/or the channel has a depth, available for receiving the light unit, of from approximately 19 mm to approximately 22 mm, for example approximately 20 mm or approximately 21 mm, for example approximately 20.5 mm. 
     According to a further embodiment, the light unit comprises a linearly elongate lens. The linearly elongate lens makes it possible in particular to ensure that, the desired light image, e.g. a light image that is as uniform as possible, over the length of the light unit and the desired light distribution are achieved along the light unit. 
     In a further embodiment, the light provision and optics unit comprises a housing component in which the lens and an LED circuit board are received. In this case, the housing component of the light provision and optics unit is mechanically coupled to the housing element of the power supply unit. In this way, the lens and the LED circuit board can be held securely by means of the housing component and thus also coupled to the power supply unit, for example. Furthermore, the lens, the LED circuit board and the housing component may together be preassembled to form a light provision and optics unit that is easy to handle, and only then be mechanically coupled to the power supply unit, for example. The LED circuit board and the lens can be protected by the housing component. Furthermore, in developments, the housing component may be transparent or opaque, depending on which aesthetic effect is intended to be achieved. 
     In a further embodiment of the invention, the lens has a cross section that is substantially constant in a longitudinal direction of the lens. In particular, the extension of the lens in a direction which is in parallel with the depth direction of the channel when the light unit is inserted is smaller than in a width direction of the lens transverse to the depth direction of the channel. It is relatively simple to produce a lens, according to this embodiment, having a substantially constant cross section. Advantageously, a lens which, according to this embodiment, has a width, transverse to the depth direction of that channel, that is larger than the height of said lens, in parallel with the depth direction of the channel, again contributes to a space-saving lighting system having a low installation depth. 
     According to a further embodiment, the connector comprises movable catches. The channel is provided, in the inner region, with longitudinal ribs, the catches of the connector being designed to engage behind the longitudinal ribs in order to latchingly couple the connector to the portions of the channel, and it being further possible for an operator to disengage the catches from the longitudinal ribs, in order to release the coupling, by actuating an actuation element or a plurality of actuation elements. Reliable mechanical coupling of the connector to the portions of the channel is possible, at the same time as low overall dimensions. 
     In embodiments of the invention, the at least one light unit, which can be arranged so as to overlap the connector within the channel may be designed in different ways, for example as a light unit for a diffused light unit for diffused lighting or a light unit for focused lighting. In this way, allowance can be made for many different kinds of lighting requirements. 
     Furthermore, in further embodiments of the lighting system, according to the invention the lighting system may comprise additional lighting inserts, it being possible to insert the additional lighting inserts into the channel and to electrically couple each of said inserts to the busbar in order to be supplied with power. An additional light unit of this kind may be designed, for example, as a spotlight, a pivotable spotlight, a suspended spotlight, a wallwasher, a linear arrangement of spotlights, or a linear lighting insert that radiates in a diffused manner. In a further embodiment, the additional light unit may be designed having a pendant lighting fixture. 
     The above embodiments and developments may, if meaningful, be combined as desired. Further possible embodiments, developments and implementations of the invention also include not explicitly mentioned combinations of features of the invention described above or below in relation to the embodiments. In particular, a person skilled in the art would also add individual aspects as improvements or additions to the particular basic form of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described below in more detail on the basis of the embodiments indicated in the schematic figures of the drawings, in which: 
         FIG. 1  is a perspective, exploded view of a lighting system according to a first embodiment; 
         FIG. 2  shows a lighting system according to the first embodiment when assembled, a light outlet side facing upwards in the figure; 
         FIG. 3  shows a cross section III-III (see  FIGS. 1 and 4 ) of the lighting system according to  FIG. 2 ; 
         FIG. 4  shows a longitudinal, central cross section IV-IV (see  FIG. 3 ) of the lighting system according to  FIG. 2 , with some components not appearing in section. 
         FIG. 5  shows a detail X from  FIG. 4 ; 
         FIG. 6  shows a detail Y from  FIG. 4 ; 
         FIG. 7  is an end view of a light unit of a lighting system according to the first embodiment; 
         FIG. 8  is a side view of the light unit in  FIG. 7 ; 
         FIG. 9  shows a cross section IX-IX (see  FIG. 8 ) of the light unit in  FIG. 7 ; 
         FIG. 10  is an end view of a power supply unit for the light unit of the lighting system according to the first embodiment; 
         FIG. 11  is a side view of the power supply unit in  FIG. 10 ; 
         FIG. 12  is a plan view of the power supply unit in  FIG. 10 ; 
         FIG. 13  is a perspective view of the power supply unit in  FIG. 10 , a first side of the power supply unit, which faces a busbar of the channel when the light unit is inserted in the channel, facing upwards; 
         FIG. 14  is a perspective view of the power supply unit in  FIG. 10 , a second side of the power supply unit, which faces a light provision and optics unit (not shown in  FIG. 14 ) when the light unit is assembled, facing upwards; 
         FIG. 15  is a perspective, exploded view of a lighting system according to a second embodiment; 
         FIG. 15A  shows a channel according to a first variant; 
         FIG. 15B  shows a channel according to a second variant; 
         FIG. 15C  shows a channel according to a third variant; 
         FIG. 16  shows the lighting system according to the second embodiment when assembled, a light outlet side facing downwards in the figure; 
         FIG. 17  is an end view of a light unit for the lighting system according to the second embodiment; 
         FIG. 18  is a side view of the light unit in  FIG. 17 ; 
         FIG. 19  shows a cross section XIX-XIX (see  FIG. 18 ) of the light unit in  FIG. 17 ; 
         FIG. 20  is a perspective view of the light unit in  FIG. 17 , a first side of the light unit, which faces a busbar of the channel when the light unit is inserted in the channel, facing upwards; 
         FIG. 21  is an end view of a light unit according to a third embodiment; 
         FIG. 22  is a side view of the light unit in  FIG. 21 ; 
         FIG. 23  shows a cross section XXIII-XXIII (see  FIG. 22 ) of the light unit in  FIG. 21 ; 
         FIG. 24  shows a further cross section of the light unit in  FIG. 21 , only a housing component of the light provision and optics unit of the light unit being shown; 
         FIG. 25  is a side view of a light unit according to a fourth embodiment; 
         FIG. 26  shows a cross section XXVI-XXVI (see  FIG. 25 ) of the light unit in  FIG. 25 ; 
         FIG. 27  shows a transverse cross section of a lighting system according to a fifth embodiment when assembled; 
         FIG. 28  shows a transverse cross section of a lighting system according to a sixth embodiment when assembled; 
         FIG. 29  is a perspective view of a connector for the lighting system according to each of the embodiments in  FIGS. 1 to 28 and 31 to 36 ; 
         FIG. 30  is a perspective view of a current supply unit for the lighting system according to each of the embodiments in  FIGS. 1 to 28 and 31 to 36 ; 
         FIG. 31  is a side view of a light unit according to a seventh embodiment; 
         FIG. 32  shows a cross section XXXII-XXXII (see  FIG. 31 ) of the light unit in  FIG. 31 ; 
         FIG. 33  is a perspective, exploded view of a lighting system according to an eighth embodiment; 
         FIG. 33A  shows variants of a channel for the lighting system according to  FIG. 33 ; 
         FIG. 34  shows a detail Z from  FIG. 33 ; 
         FIG. 35  is a further perspective, exploded view of the lighting system in  FIG. 33 ; and 
         FIG. 36  shows the lighting system according to the eighth embodiment when assembled, a light outlet side facing downwards in the figure. 
     
    
    
     The accompanying drawings are intended to impart further understanding of the embodiments of the invention. Said drawings illustrate embodiments and are used, in conjunction with the description, to explain principles and concepts of the invention. Other embodiments and many of the mentioned advantages emerge in view of the drawings. The elements of the drawings are not necessarily shown to scale. 
     In the figures of the drawings, elements, features and components that are the same, have the same function or act in the same manner—unless stated otherwise—are each provided with the same reference signs. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1-3  show a lighting system  1  according to a first embodiment, which comprises a channel  3  formed having portions  2 , and light units  4  and a connector  5 . The channel  3  is formed such that the portions  2  are assembled so as to adjoin one another at the end faces thereof at a junction point  6 . In this way, a long channel  3  can be produced from shorter portions  2  that are easy to handle. The channel  3  may be formed having two or more portions  2 . 
     The length of a portion  2  is denoted in  FIG. 2  as L 2 , it being possible for portions  2  of different lengths L 2  to be used. For example, portions  2  for which L 2 =1,000 mm or L 2 =2,000 mm or L 2 =3,000 mm could be provided for the composition of the channel  3 . It is conceivable for an individual cut to be made to any desired length L 2 . 
     The portions  2  are each formed having an extruded profile body  7 , e.g. made of aluminium or an aluminium alloy, and a busbar portion  8  that may be latchingly attached therein. For example, the busbar portions  8  and the portions  2  have substantially the same length L 2 . In an inner region  9  of the channel  3 , the channel  3  therefore comprises a busbar  10  that forms a part of the channel  3  and is formed having the busbar portions  8 , which adjoin one another at the junction point  6 . 
     The channel  3  may be built into a plasterboard ceiling or wall (not shown in any more detail in the drawings), for example so as to be edgeless. Once built-in, the channel  3  may thus be approximately flush with a ceiling plane E, for example. This is outlined in  FIG. 3 , by way of example. The channel  3  may thus be designed as a built-in channel for being built into a wall or ceiling. Additionally or alternatively, the channel  3  may be designed as a mounting channel, i.e. the channel  3  may be fixedly mounted on a wall or ceiling (not shown in any more detail in the drawings). Furthermore, additionally or alternatively the channel  3  may be designed to be mounted so as to be suspended from a ceiling. 
     The light units  4  and the connector  5  can each be inserted into the channel  3 ; the channel  3  thus receives the light units  4  and the connector  5 . The busbar  10  is designed to supply each of the light units  4  inserted in the channel  3  with electrical current for the operation thereof, for example at a voltage of 48 volts. For this purpose, each of the light units  4  can be electrically coupled to the busbar  10 . 
     The light units  4  are each linearly elongate and are together designed to form, when inserted in the channel  3 , a continuous strip light during operation. The length of the light unit  4  is denoted as L 4  (see  FIG. 1 ). The strip light produced is substantially not interrupted in the region of the junction point  6 ; said light is continuous and aesthetically pleasing and has no noticeable non-luminous regions. The number of light units  4  may vary depending on the total length of the channel  3  and depending on the length L 4  of the individual light units  4 . 
     The bus bar  10 , formed having the busbar portions  8 , is arranged in the region of a base of the channel  3  (see  FIG. 3 ), a main body  19  of the busbar portion  8  comprising latching elements  16  that latchingly engage behind rib-like undercuts  17  on the two side walls  18  of the profile body  7  in order to hold the busbar portions  18  in the profile body  7 . The main body  19  is formed of a plastics material and receives two electrical conductors  20  for providing the electrical current. 
     A flow of current in the busbar  10  across the junction point  6  is made possible by the adjacent busbar portions  8  being electrically coupled to one another at the junction point  6  by means of the connector  5  inserted in the channel  3 . Depending on the number of the portions  2  and junction points  6 , a plurality of connectors  5  may be used. 
     Each of the light units  4  in  FIG. 1  comprises a shallow power supply unit  11  and a light provision and optics unit  12 . The power supply unit  11  is mechanically coupled to the light provision and optics unit  12 . In this regard, the power supply unit  11  comprises a housing element  13  that is provided with latching devices  14 . The latching devices  14 , of which only some are provided with reference signs in  FIG. 1  for the sake of clarity, latchingly connect, and thus mechanically couple, the power supply unit  11  to the light provision and optics unit  12 . 
     The light units  4  each comprise a light outlet region  15  that is shown in dots in  FIG. 2  for one light unit  4  and extends over substantially the entire length L 4  of the light unit  4  and also over substantially the entire width thereof transverse to the longitudinal direction L′. In the light outlet region  15 , the light unit  4  can emit light during operation. 
       FIG. 3  shows one of the light units  4  when inserted in the channel  3  in more detail. The light unit  4  in  FIG. 3  comprises a light provision and optics unit  12  which, in turn, comprises a transparent, opal housing component  21 . The housing component  21  is closed on the side of the light outlet region  15 , provided with an interior  22 , and provided with an opening  23  on a side facing the power supply unit  11 . 
     The power supply unit  11  is mechanically coupled to the light provision and optics unit  12  such that the latching devices  14  engage behind sloping ribs  27 , which are provided on either side of the housing component  21  and project laterally from the housing component  21 , and thus mechanically couple the housing element  13  to the housing component  21 . 
     Within the housing component  21 , an LED circuit board  24  having light-emitting diodes or LEDs  25  is received, of which only one LED  25  can be seen in  FIG. 3 . Optionally further electrical and/or electronic components necessary for operating the LEDs  25  may be arranged on the LED circuit board  24 . 
     The housing component  21  further receives a linearly elongate lens  26 . In the embodiment shown in  FIG. 3 , the lens  26  shown in cross section in  FIG. 3  is formed a cross section that is constant in a longitudinal direction thereof that extends in parallel with the longitudinal direction L′ of the light unit  4  (see  FIG. 1 ). The lens  26  is provided, on a side facing the LED circuit board  24 , with a recess  28  that receives the LEDs  25 . In cross section, the lens  26  is formed having narrow edge regions  29  which, together with the LED circuit board  24 , are held by ribs  30  on the housing component  21  that project into the interior  22 , and having a thicker middle region  31  which protrudes into the not completely filled interior  22  towards the light outlet region  15 . In the cross section of the lens  26 , the middle region  31  is rounded on either side of the middle and, in a middle part, is formed having a shallow depression  32  on a side of the lens  26  facing away from the LED circuit board  24 . By means of the shape of the lens  26 , an advantageously uniform light distribution on the light outlet region  15 , formed by a region of the opal housing component  21  that is visible from the outside on the viewing side S, is achieved. 
     The LED circuit board  24  is supplied with electrical current through the opening  23 . For this purpose, contact elements  33  are provided which allow the LED circuit board  24  of the light provision and optics unit  12  to be electrically coupled to the power supply unit  11 . 
       FIG. 3  illustrates that, when inserted in the channel  3 , the light unit  4  is, in the first embodiment, received substantially completely in the channel  3 , i.e. within the inner region  9  of said channel. The housing component  21  may be flush with edges  34 ′ of an opening  35 ′ in the channel  3  or protrude slightly beyond the edges  34 ′ by a few tenths of a millimeter, for example. In the embodiment in  FIG. 3 , the opening  35 ′, which is formed between the side walls  18  of the profile body  7 , is substantially filled by the light provision and optics unit  12  of the light unit  4 . The channel  3  is therefore substantially filled by the light unit  4  on a viewing side S, in particular in a transverse direction Q of the channel  3 , the light unit  4  occupying the largest part of the inner region  9  in  FIG. 3 . 
       FIG. 4  shows a central, longitudinal section of the lighting system  1  in  FIG. 1 , the channel  3  being shown in section; the light units  4  and the connector  5  are, however, not shown in section.  FIG. 5  shows a detail X in the region of the junction point  6 .  FIG. 6  shows a further detail Y in the region of a power supply unit  11 . 
     When inserted in the channel  3 , as in  FIG. 2-6 , within the channel  3  each of the two light units  4  overlaps the connector  5 , which is likewise inserted in the channel  3  in order to electrically couple the busbar portions  8  (see  FIG. 5 ). More specifically, an end portion  34  of each of the two light units  4  overlaps the connector  5  such that, in a longitudinal direction of the channel, the end portions  34  directly adjoin one another on end faces  35  of the light units  4  at the location of the junction point  6 . 
     As seen from the viewing side S of the channel  3 , the light units  4  and therefore the lighting system  1 , the connector  5  is therefore substantially completely concealed by the end portions  34 . 
     A length L 11  of the power supply unit  11  is considerably smaller than the length L 4  of the light unit  4 . For example, in  FIG. 1-6 , it holds that: L 11 ≤(L 4 /2). In the same way as the length L 4 , the length L 11  is taken to be in the longitudinal direction L′ of the light unit  4 . By way of example it may be that L 11 =148.4 mm. 
     The end portions  34  that overlap the connector  5  therefore form parts of end portions  36  in which the light provision and optics unit  12  projects beyond the power supply unit  11  in the longitudinal direction L′ (see  FIG. 1  and  FIG. 4 ).  FIG. 1  also shows that, in the first embodiment, the power supply unit  11  sits centrally on the light provision and optics unit  12  in the longitudinal direction L′, and that an end portion  36  of the light provision and optics unit  12  thus projects on either side of the power supply unit  11  in the longitudinal direction L′. 
     By the light units  4  and the connector  5  overlapping within the channel  3 , continuous strip lights can be produced that do not have unlit points, even if the channel  3  is composed of a plurality of portions  2 . By means of parts of the end portions  36 , the light unit  4  can therefore sit over the connector  5 , with the light unit  4  and the connector  5  not being directly interconnected. The light unit  4  may simply rest on the shallow connector  5 , or a small gap may be formed between the light unit  4  and the connector  5  in the portion  36 . In the longitudinal direction L′, the connector  5  is shorter than the power supply unit  11 , i.e. L 5 &lt;L 11 . 
     The light unit  4  is shown separately in  FIG. 7-9 . In the cross section in  FIG. 9 , additional internal parts of the power supply unit  11  can be seen. Further features of the power supply unit  11  are shown in  FIG. 10-14 . 
     The power supply unit  11  comprises contact devices  36 ′ that are in the form of pins in  FIG. 9 . The contact devices  36 ′ are provided for each being brought into contact with one of the conductors  20  and thereby allowing the light unit  4  to be electrically coupled to the busbar  10 . 
     A circuit board  37  is received within the housing element  13  (see  FIG. 9  and  FIG. 14 ). The circuit board  37  is held in the housing element  13  by means of latching elements  39  and rests on shoulders  40  of the housing element  13 . 
     The contact devices  36 ′ are connected to the circuit board  37 . Furthermore, on the circuit board  37  a module  41  is provided, in particular implemented as a part of the circuit board or arranged thereon, the module  41  being designed to wirelessly receive control signals for switching and/or controlling the light output of the light provision and optics unit  12  of the light unit  4 . This allows for the ability to wirelessly switch and/or control, in particular dim, the light output of the light unit  4 . In addition to or as part of the module  41 , further devices or components may be provided on the circuit board  37  in order to process and/or analyse the received switching and/or control signals and to provide electrical current, for operating the LEDs  25 , by means of the contact elements  33  of the LED circuit board  24  on the basis of the switching and/or control signals. In this way, the light provision and optics unit  12  is thus supplied with current on the basis of wireless switching and/or control signals, which may in particular be radio signals. The module  41  may in particular be designed as or comprise what is known as a Zigbee module. The module  41  is shown schematically in  FIG. 14 . The power supply unit  11  can therefore also be considered to be a communications unit of the light unit  4 , a shallow design of the circuit board  37  and of the components arranged thereon advantageously contributing to the power supply unit  11  being shallow and space-saving. 
     As seen in a longitudinal direction L″ of the power supply unit  11 , which is in parallel with the longitudinal direction L′ in the assembled state, the circuit board  37  is arranged centrally within the housing element  13 . In the longitudinal direction L″, at each of the two ends of the circuit board  37 , each in an end region of the housing element  13 , a cuboid permanent magnet  42  is received in the housing element  13 , i.e. the power supply unit  11  comprises two permanent magnets  42 . Each permanent magnet  42  is held by latching devices  43  (in the form of sloped lugs in the example shown) which engage behind the permanent magnet  42 . 
     The housing element  13  comprises, on a side facing the base of the channel  3  and thus the busbar  10  when the light unit  4  is inserted in the channel  3 , a cover portion  44  and wall portions  45   a - d  that protrude substantially perpendicularly from the cover portion  44  on all four edges thereof. The wall portions  45   a  and  45   c  on the longitudinal sides of the housing element  13  are each lengthened by mutually spaced projections  46  in the manner of crenellations in the extension direction of said wall portions that is normal to the cover portion  44 . Each of the projections  46  has, at the free end thereof, a latching hook  47 . The projections  46  having the latching hooks  47  form the latching devices  14 . For the sake of clarity, this is only shown for some latching devices  14  in  FIG. 14 . 
     The cover portion  44  is provided with two cross-shaped holes  48 , it being possible to see one permanent magnet  42  through each of the holes  48  (see  FIGS. 12 and 13 ). The cover portion  44  also comprises through-openings  38 , by means of which the contact devices  36 ′ pass through the housing element  13 . 
     From a rear side of the light provision and optics unit  12  facing away from the light outlet region  15  (see  FIG. 9 , for example), the power supply unit  11  is latched on the housing component  21 . The plurality of latching hooks  47  engage behind the longitudinal ribs  27 , as a result of which the power supply unit  11  and the light provision and optics unit  12  are securely coupled to one another. 
     The power supply unit  11  is not only used to supply the light provision and optics unit  12  with electrical power, but rather is also designed as a holding unit for the light unit  4  in order to hold the light unit  4  in the channel  3 . Once inserted in the channel  3 , the light unit  4  is magnetically coupled to the channel  3  by means of the permanent magnets  42  and reliably held in the channel  3 . For this purpose, the portions  2  of the channel  3  comprise portions  49  of a steel core  50 , the steel core  50 , as a ferromagnetic element, interacting with the permanent magnet  42  so as to attach the light units  4 . In the same way as the busbar  10 , the steel core  50  also forms part of the channel  3 . The portions  49  are held within the profile body  7  by means of the main body  19  (see in particular  FIGS. 2 and 3 ). 
     Wirelessly controlling the light unit  4  by means of the module  41  makes it possible to circumvent the space requirements associated with a wired control system. Additional contact elements for picking up the control signals, and space therefor on the circuit board, are not necessary. This makes it possible to keep the power supply unit  11  particularly slim and narrow. Furthermore, it is also possible for the connector  5  to be very shallow, especially as no control lines, rather only the two conductors  20 , have to be electrically coupled across the junction point  6 . 
     The housing element  13  may be injection-moulded. The housing element  13  may be designed as an injection-moulded plastics part. 
       FIG. 29  shows the connector  5  separately. The connector  5  comprises a substantially cuboid connector housing  51  formed having two parts. The connector housing  51  is formed having a connector housing part  51   a  and a connector housing part  51   b , the connector housing parts  51   a ,  51   b  each being formed of a plastics material. The connector housing parts  51   a ,  51   b  may also be injection-moulded, for example. 
     Close to the four corners of the cuboid connector  5 , movable catches  52   a ,  52   b  are arranged on the longitudinal sides of said connector. Only two of these are shown in  FIG. 29 ; however, it is understood that the further two catches  52  are provided on the longitudinal side of said connector that is obscured in  FIG. 29 , so as to be symmetrical with respect to the longitudinal direction L′″ of the connector  5 ; in particular, the second catch  52   a  is in symmetry with catch  52   a  that can be seen in  FIG. 29 , and the second catch  52   b  is in symmetry with the catch  52   b  that can be seen in  FIG. 29 . 
     The connector  5  also comprises, at each of the opposite end-face ends  53 , an actuation element  54   a ,  54   b , of which likewise only one can be seen in  FIG. 29 , although both are shown in  FIG. 5 . 
     In order to be actuated, the actuation elements  54   a  and  54   b  can be pushed in, as a result of which the catches  52   a ,  52   b  can be retracted into the connector housing  51 , which catches protrude from the connector housing  51  when the actuation elements  54   a ,  54   b  are not actuated. For example, the actuation element  54   a  may act on the two catches  52   a  at one end-face end  53  of the connector housing  51 , and the actuation element  54   b  may act on the catches  52   b  at the other end-face end  53  of the connector housing  51 . An appropriate mechanism may be provided inside the connector housing  51 . 
     The catches  52   a ,  52   b  form latching devices, which make it possible to latchingly, and detachably, mechanically couple the connector  5  to two adjoining portions  2  of the channel  3  at the junction point  6  in a space-saving manner. In the process, the catches  52   a  and  52   b  engage behind longitudinal ribs  55  in the inner region  9  of the channel  3  (see  FIG. 3 ), the longitudinal ribs  55  being formed in the side walls  18  of the profile body  7  and being sloped towards the opening  35 ′. In this way, the connector  5  is held on the portions  2  of the channel  3  and can, in addition to the electrical coupling of the busbar portions  8 , also mechanically guide the portions  2  in a simple manner in the region of the junction point  6  and make it easier to align the portions  2  with one another. 
     By actuating the actuation elements  54   a, b , the catches  52   a, b  can be retracted into the connector housing  51 , as a result of which the catches  52   a, b  are disengaged from the longitudinal ribs  55  (see  FIG. 3 ), and the connector  5  can be removed again. 
     In order to electrically couple the busbar portions  8  that meet at the junction point  6 , the connector  5  comprises two pairs of contact elements  56   a  and  56   b  (see  FIG. 29 ). When the connector  5  is inserted into the channel  3 , the contact elements  56   a, b  come into contact with the conductors  20  on either side of the junction point  6  such that the contact elements  56   a  connect portions of one conductor  20 , and the contact elements  56   b  connect portions of the other conductor  20 , across the junction point  6 . For this purpose, both the contact elements  56   a  and the contact elements  56   b  are electrically interconnected in the connector housing  51 . 
       FIG. 3  illustrates, for the first embodiment, a depth direction T of the channel  3  and a transverse direction Q of the channel  3  that is normal and thus transverse to the depth direction T. 
     In  FIG. 9 , for the state in which the light unit  4  is inserted in the channel  3 , an extension of the light unit  4  in parallel with the depth direction T is denoted as T 4 , an extension of the light provision and optics unit  12  in parallel with the depth direction T is denoted as T 12 , and an extension of the lens  26  in parallel with the depth direction T is denoted as T 26 . The measurement of T 12  and T 4  does not take into account the contact elements  33  and the contact devices  36 ′ (see  FIG. 9 ). 
     In  FIG. 9 , in the transverse direction Q, which extends in parallel with a width direction B (see  FIG. 3 ) of each of the lens  26 , the light provision and optics unit  12  and the power supply unit  11  when the light unit  4  is inserted, the extension of the light provision and optics unit  12  is denoted as B 12 , and the extension of the lens  26  is denoted as B 26 . For the lens  26  in  FIGS. 3 and 9 , it holds that B 26 &gt;T 26 . 
     Furthermore, for the state in which the light unit  4  is inserted in the channel  3 ,  FIG. 10  shows an extension B 13  of the housing element  13  in the transverse direction Q and thus in a width direction of the housing element  13 , an overall extension T 13  of the housing element  13  in parallel with the depth direction T, and an extension T 45  of said housing element in parallel with the depth direction T without the projections  46 . The measurement of T 13  and T 45  does not take into account the contact devices  36 ′ either. 
     Furthermore,  FIG. 3  shows the outer dimensions in the cross section of the channel  3 , i.e. the height T 2  of the channel  3  and of the portions  2  in parallel with the depth direction T, and the width B 2  of the channel  3  and of the portions  2  in the transverse direction Q and thus normal to the depth direction T. 
     In the first embodiment, it may be that B 2 =31.0 mm and T 2 =31.0 mm, by way of example. 
     For the light unit  4  of the first embodiment, it holds that B 13 &gt;0.9 B 12 . Therefore, the width extension of the housing element  13 , and thus also of the power supply unit  11 , in the transverse direction Q normal to the depth direction T is greater than 90 percent of the width extension B 12  of the light provision and optics unit  12  in said direction. By way of example, in the first embodiment it holds that B 12 =27.2 mm and B 13 =25.7 mm. 
     Furthermore, by way of example, for the light unit  4  of the first embodiment it holds that T 12 =14.1 mm and T 4 =20.5 mm. Thus, in the first embodiment, it further holds that T 4 &lt;B 12 , B 12  also indicating the maximum extension of the light unit  4  in the width direction B, i.e. in the transverse direction Q. 
     Furthermore, by way of example, in the case of the power supply unit  11  according to the first embodiment, it holds that T 13 =9.5 mm and T 45 =6.2 mm. 
     By way of example, a thickness D 51  of the connector housing  51  (see  FIG. 29 ), which denotes an extension of the connector housing  51  in the thickness direction D of the connector  5  and does not take the contact elements  56   a, b  into account, is approximately 6 mm. When the connector  5  is inserted in the channel  3 , the thickness direction D is substantially in parallel with the depth direction T of the channel  3 . In particular, the thickness D 51  is approximately of a dimension (by way of example, it holds that T 4 −T 12 =6.4 mm in this case) at which, in the case of the light unit  4  (see  FIG. 9 ), the housing element  13  projects, in parallel with the depth direction T, beyond the light provision and optics unit  12 , and in particular beyond the housing component  21  thereof, when the light unit  4  is inserted in the channel  3 . For example, the thickness D 51  is not greater than the projection T 4 −T 12 . 
     By way of example, a depth T 9 ′ of the channel  3  (see  FIG. 3 ), available for receiving the light unit  4 , is approximately 20.5 mm. The light unit  4  received in the channel  3  thus ends substantially flush with the edges  34 ′. Furthermore, by way of example, an inner width W 2  of the channel  3  (see  FIG. 3 ) in the region of the opening  35 ′ is approximately 28 mm. 
     Furthermore,  FIG. 3  shows that the width B 13  of the housing element  13  is selected substantially such that the power supply unit  11  can be easily introduced between the side walls  18 , the spacing of which at the location of the power supply unit  11  is, in the transverse direction Q, smaller than the width W 2  when said power supply unit is inserted. When the connector  5  is inserted, the width B 51  of the connector housing  51  (see  FIG. 29 ) in the transverse direction Q may substantially correspond to the width B 13 . 
       FIG. 15  shows a lighting system  1  according to a second embodiment. The following is intended to explain the differences in relation to the first embodiment. For other features, in particular relating to the channel  3  and the portions  2  thereof and in particular also relating to the busbar  10  and the busbar portions  8  thereof, reference is made to the above observations concerning the first embodiment. 
     For illustration, two portions  2  of the channel  3  that have different lengths L 2   a , L 2   b  are shown in  FIG. 15 .  FIG. 15  also shows two light units  104   a ,  104   b  having different lengths L 104   a &gt;L 104   b . Each of the light units  104   a ,  104   b  comprises a light provision and optics unit  112   a ,  112   b , respectively. Furthermore, the longer light unit  104   a  comprises, for example, two identical power supply units  11 , while the shorter light unit  104   b  is provided with only one power supply unit  11 . 
     Furthermore, a portion  136  of the light provision and optics unit  112   a  completely overlaps the connector  3  (see  FIG. 15 ). The connector  5  is substantially completely concealed by the portion  136 ; however, in the arrangement in  FIG. 15 , the two light units  104   a  and  104   b  adjoin one another on the end faces thereof not in front of the connector  5 , but outside of the region in which the connector  5  is located in the channel  3 . The portion  136  that overlaps the connector  5  is not therefore an end portion, but an inner portion of the light provision and optics unit  112   a.    
     It is also conceivable for a portion  136  of a light provision and optics unit  112   a  that is located between two power supply units  11  to overlap the connector  5 , provided that the power supply units  11  are spaced far enough apart from one another. 
     By way of example,  FIGS. 15A, 15C and 15B  show alternative profile bodies  7 ′,  7 ″,  7 ′″ having the inner region  9 ′,  9 ″,  9 ′″, respectively, which may be used for alternative mounting situations in place of the profile body  7  in  FIG. 3  for the channel  3  according to the second, or also the first, embodiment. 
       FIG. 15  also shows a current supply unit  57  for supplying electrical current to the busbar  10  of the channel  3 . As can be seen in  FIG. 15 , the current supply unit  57  can be inserted into the channel  3  in a similar manner to the connector  5 , such that said unit is overlapped by the light unit  4  and in particular by a portion of the light provision and optics unit, e.g.  112   a , and is completely concealed by said portion, for example. 
       FIG. 30  shows the shallow current supply unit  57 , which can be latched into the channel  3 , together with a piece of line  58 . The current supply unit  57  comprises a substantially cuboid current supply unit housing  61 , which is formed having two housing parts  61   a ,  61   b . The housing parts  61   a ,  61   b  are each formed of a plastics material and are likewise injection-moulded, for example. 
     At one end-face end  62   a  of the current supply unit  57 , the flexible, current-carrying line  58  enters the housing  61 , while, at the opposite end-face end  62   b  of the current supply unit  57 , said current supply unit comprises an actuation element  63  (not visible in  FIG. 30 ), which is designed in the same way as the actuation element  54   a  or  54   b  of the connector  5 . 
     Adjacently to the end  62   a , the current supply unit  57  comprises latching lugs  59 , which are arranged on the longitudinal sides so as to be symmetrical with respect to the longitudinal direction of said current supply unit, while, adjacently to the end  62   b , the current supply unit  57  comprises, on the longitudinal sides thereof, two movable catches  60 . The catches  60  are also symmetrical with respect to the longitudinal direction of the current supply unit  57 . The latching lugs  59  can each engage behind one of the longitudinal ribs  55  (see  FIG. 3 ) in a resiliently latching manner. In the same way as the catches  52   a ,  52   b  in  FIG. 29 , the catches  60  are also designed to engage behind the longitudinal ribs  55 . The latching lugs  59  and the catches  60  thus form latching devices that make it possible to latchingly, and releasably, mechanically couple the current supply unit  57  to the channel  3 . 
     In order to be actuated, the actuation element  63  can be pushed in, as a result of which, in the same way that the catches  52   a ,  52   b  of the connector  5  function, the catches  60  can be withdrawn, which catches protrude from the current supply unit housing  61  when said actuation element is not actuated. Once the actuation element  63  has been actuated, the coupling of the current supply unit  57  to the channel  3  is released. 
     An electrical coupling of the busbar  10  to the current supply unit  57  is achieved by contact elements  64   a ,  64   b , which are each electrically connected to a conductor of the line  58 . When the current supply unit  57  is inserted into the channel  3 , the contact element  64   a  comes into contact with one conductor  20  (see  FIG. 3 ), and the contact element  64   b  comes into contact with the other conductor  20 . 
     A thickness  61  of the current supply unit housing  61  in a thickness direction, which is substantially in parallel with the depth direction T when the current supply unit  57  is inserted, may correspond approximately to the thickness D 51  of the connector housing  51 , for example. Furthermore, a width B 61  of the current supply unit housing  61  in a width direction, which extends normal to the depth direction T when the current supply unit  57  is inserted, may correspond approximately to the width B 51  of the connector housing  51 , for example. 
       FIG. 16  shows how, when the lighting system is assembled, the line  58  may be guided out of the channel  3  at the end thereof, between the busbar  10  and the light provision and optics unit  112   a , for example, in order to connect the line  58  to a current source, such as a converter. 
     A light unit  104  (not shown in  FIG. 15 ) for the lighting system according to the second embodiment is shown in more detail in  FIG. 17-20 , the following observations concerning  FIG. 17-20  similarly applying to the light units  104   a ,  104   b  in  FIG. 15 . 
     The light unit  104  comprises a power supply unit  11  and a light provision and optics unit  112 . The power supply unit  11  in  FIG. 17-20  is designed in the same way as in the first embodiment. The differences between the light provision and optics unit  112  and the light provision and optics unit  12  are explained in the following. 
     The light provision and optics unit  112  comprises a housing component  121  that is open towards the viewing side S and the light outlet region  15 . In an interior  122  of the housing component  121 , a linearly elongate lens  126  is received and held in the housing component  121 , for example, by latching edge regions  129  of the lens  126  into shallow recesses  130 . A front  126   a  of the lens  126  through which light is emitted is substantially planar. 
     An LED circuit board  124  having LEDs  125  is received in the housing component  121 . The lens  126  has a recess  128  which is opposite the LEDs  125 . The cross section of the lens  126  is substantially constant in a longitudinal direction thereof. An extension of the lens  126 , when the light unit  104  is inserted in the channel  3 , in parallel with the depth direction T is, in the case of the lens  126  too, smaller than an extension of the lens  126  in the transverse direction Q normal to the depth direction T. The lens  126  is designed to produce a symmetrical light distribution. 
     In order for the power supply unit  11  to be latched to the light provision and optics unit  112  in the same way as in the first embodiment, the housing component  121  comprises lateral longitudinal ribs  127 , behind which the latching devices  14  can be latched when the light unit  104  is assembled. 
     By way of example, the extension T 104  of the light unit  104  in parallel with the depth direction T may be T 104 =20.5 mm in  FIG. 19 . Furthermore, by way of example, an extension T 112  of the light provision and optics unit  112  in parallel with the depth direction T may be T 112 =14.3 mm in  FIG. 19 . By way of example, the extension B 112  of the light provision and optics unit  112  in the width direction B, which extends in parallel with the transverse direction Q when the light unit  104  is inserted, is B 112 =25.4 mm in  FIG. 19 . For the light unit  104 , it holds that B 13 &gt;0.9 B 112 , in particular that B 13 &gt;B 112 . Furthermore, in the second embodiment it holds that T 104 &lt;B 112  and T 104 &lt;B 13 . The projection of the power supply unit  11  beyond the light provision and optics unit  112  by T 104 −T 112 =6.2 mm substantially corresponds to the thickness D 51  of the connector housing  51  or is slightly larger than D 51 . 
       FIG. 21-24  illustrate a light unit  204  according to a third embodiment. The following is intended to describe primarily the differences in comparison with the light unit  104 . 
     The light unit  204  comprises a power supply unit  11  and a light provision and optics unit  212 , a housing component  221  of the light provision and optics unit  212  substantially being designed in the same way as the housing component  121  in  FIG. 19  and comprising an interior  222 , an opening  223  towards the power supply unit  11 , lateral longitudinal ribs  227  for being latched to the latching devices  14  of the power supply unit  11 , and recesses  230 . 
     In the interior  222 , a linearly elongate lens  226  is received, the cross section of which is substantially constant in a longitudinal direction of the lens  226 . A front  226   a  of the lens  226  through which light is emitted is also substantially planar, as far as edge zones. Edge regions  229  of the lens  226  are latched into the recesses  230  in the housing component  221 . 
     An LED circuit board  224  having LEDs  225  is also received in the housing component  222 . Facing the LED circuit board  224 , the lens  226  has a recess  228  in which the LEDs  225  are arranged and into which they radiate. 
     In the case of the lens  226  too, the extension thereof, when the light unit  204  is inserted in the channel  3 , in parallel with the depth direction T is smaller than the extension of the lens  226  in the transverse direction Q normal to the depth direction T. The lens  226  may be designed to focus the emitted light to a greater degree. 
     By way of example, the extension T 204  of the light unit  204  in parallel with the depth direction T may be T 204 =20.3 mm in  FIG. 23 . Furthermore, by way of example, an extension T 212  of the light provision and optics unit  212  in parallel with the depth direction T may be T 212 =14.1 mm in  FIG. 23 . By way of example, the extension B 212  of the light provision and optics unit  212  in the width direction B, which in turn extends in parallel with the transverse direction Q when the light unit  204  is inserted, is B 212 =25.4 mm in  FIG. 23 . For the light unit  204 , it holds that B 13 &gt;0.9 B 212 , in particular that B 13 &gt;B 212 . Furthermore, in the third embodiment it holds that T 204 &lt;B 212  and T 204 &lt;B 13 . In this embodiment too, the projection of the power supply unit  11  beyond the light provision and optics unit  212  by T 204 −T 212 =6.2 mm substantially corresponds to the thickness D 51  of the connector housing  51  or is slightly larger than D 51 . 
       FIGS. 25 and 26  illustrate a light unit  304  according to a fourth embodiment. With regard in particular to the power supply unit  11  of the light unit  304 , reference is again made to the above observations. The following is intended to describe primarily the differences between the light unit  304  and the above embodiments. 
     The light unit  304  comprises a light provision and optics unit  312  that comprises a housing element  321  having an interior  322 . An LED circuit board  324 , having LEDs  325 , and a lens  326  are received in the interior  322 . The lens  326  is linearly elongate, has a cross section that is substantially constant in the longitudinal direction thereof, and is designed to produce an asymmetric light distribution. 
     A front  326   a  of the lens  326  through which light is emitted is also substantially planar, as far as edge zones. Edge regions  329  of the lens  326  are latched into recesses  330  in the housing component  321  (see  FIG. 26 ). In this case, in the region of the front  326   a , the lens  326  does not extend over the entire width of the housing component  321 , but rather an opening in the housing component  321 , in the region of the edges of which opening the recesses  330  are arranged, is narrower than in the examples in  FIG. 19 or 23  on account of a wall portion  321   a  that is substantially parallel to the front  326   a.    
     Facing the LED circuit board  324 , the lens  326  has a recess  328  in which the LEDs  325  are arranged and into which they radiate. In the case of the lens  326  too, the extension thereof, when the light unit  304  is inserted in the channel  3 , in parallel with the depth direction T is smaller than the extension of the lens  326  in the transverse direction Q normal to the depth direction T. 
     By way of example, the extension T 304  of the light unit  304  in parallel with the depth direction T may be T 304 =25.2 mm in  FIG. 26 . Furthermore, by way of example, an extension T 312  of the light provision and optics unit  312  in parallel with the depth direction T may be T 312 =19 mm in  FIG. 26 . By way of example, the extension of the light provision and optics unit  312  in the width direction B, which in turn extends in parallel with the transverse direction Q when the light unit  304  is inserted, is B 312 =25.4 mm in  FIG. 26 . For the light unit  304 , it thus holds that B 13 &gt;0.9 B 312 , in particular that B 13 &gt;B 312 . Furthermore, in the fourth embodiment it holds that T 304 &lt;B 312  and T 304 &lt;B 13 . However, in the fourth embodiment, T 304  and B 312  are practically equal. In particular, when the light unit  304  is inserted into the channel  3  in  FIG. 3 , the light unit  304  protrudes beyond the edges  34 ′ and out of the opening  35 ′ in the channel  3 . In this embodiment too, the projection of the power supply unit  11  beyond the light provision and optics unit  312  by T 304 −T 312 =6.2 mm substantially corresponds to the thickness D 51  of the connector housing  51  or is slightly larger than D 51 . 
       FIG. 27  illustrates a fifth embodiment, a light unit  404  projecting from the interior  9  beyond the edges  34 ′ and out of the opening  35 ′ in the channel  3 . All the same, the light unit  404  overlaps the connector  5  (not shown in  FIG. 27 ) within the channel  3 . 
     In the sixth embodiment of  FIG. 28 , a light unit  504  is provided, which is dimensioned in relation to the channel  3  such that, when inserted, the light unit  504  is offset with respect to the edges  34 ′. The light unit  504  is thus completely received in the interior  9  of the channel  3 , but not flush with the edges  34 ′ of the opening  35 ′. 
       FIGS. 31 and 32  illustrate a light unit  604  according to a seventh embodiment. In the same way as the light unit  304 , the light unit  604  is also used to produce an asymmetric light distribution. The following is intended to primarily describe the differences between the light unit  604  and the light unit  304 , reference otherwise being made to the above observations. 
     In addition to an LED circuit board  624  having LEDs  625 , a housing element  621  of a light provision and optics unit  612  of the light unit  604  receives, in the interior  622  thereof, a linearly elongate lens  626  which, however, on the viewing side S, extends over substantially the entire width of the housing element  621  (see  FIG. 32 ), unlike the above-described lens  326 . In  FIG. 32 , the substantially planar front  626   a  of the lens  626  through which light is emitted thus extends over a large part of the width of the housing element  621 . Edge regions  629  of the lens  626  are latched into recesses  630  in the housing component  621 . 
     Facing the LED circuit board  624 , the lens  626  also has a recess  628  in which the LEDs  625  are arranged. In the case of the lens  626  too, the extension of the lens  626 , when the light unit  604  is inserted in the channel  3 , in parallel with the depth direction T is smaller than the extension of the lens  626  in the transverse direction Q normal to the depth direction T. 
     By way of example, the extension T 604  of the light unit  604  in parallel with the depth direction T may be T 604 =20.3 mm in  FIG. 32 . Furthermore, by way of example, an extension T 612  of the light provision and optics unit  612  in parallel with the depth direction T may be T 612 =14.1 mm in  FIG. 32 . By way of example, the extension of the light provision and optics unit  612  in the width direction B, which in turn extends in parallel with the transverse direction Q when the light unit  604  is inserted, is B 612 =25.4 mm in  FIG. 32 . For the light unit  604 , it thus holds that B 13 &gt;0.9 B 612 , in particular that B 13 &gt;B 612 . Furthermore, in the seventh embodiment it holds that T 604 &lt;B 612  and T 604 &lt;B 13 . In particular, when the light unit  604  is inserted into the channel  3  in  FIG. 3 , the light unit  604  is substantially flush with the edges  34 ′. In this embodiment too, the projection of the power supply unit  11  beyond the light provision and optics unit  612  by T 604 −T 612 =6.2 mm substantially corresponds to the thickness D 51  of the connector housing  51  or is slightly larger than D 51 . 
       FIG. 33-36  show a lighting system  1  according to an eighth embodiment, the following being intended to explain the differences from the second embodiment. Reference is otherwise made to the observations concerning the second embodiment. 
     When the lighting system  1  is assembled according to the eighth embodiment, the line  58  is guided out of the channel  3  through a passage  765  in the portion  2  of the channel  3  in order to connect the line  58  to a current source, such as a converter. In  FIGS. 33 and 34 , the passage  765  is designed as a through-bore in the portion  2  of the channel  3 , close to an end-face end of the portion  2 . For this purpose, the passage  765  is made in the profile body  7  as a bore. In order to make it possible to access the passage  765 , the busbar portion  8  may be slightly shorter than the portion  2  of the channel  3 , such that the busbar portion  8  does not obscure the passage  765 . 
     In  FIG. 33 , ends of the channel  3  that are at the end faces in the longitudinal direction are each closed by an end cover  766  that is substantially rectangular in the example in  FIG. 33 , as a result of which a sealed lighting system is provided. 
     For the lighting system  1  according to the eighth embodiment, two light units  704   a ,  704   b  are shown in  FIG. 33 , for example. The light unit  704   a  is designed such that it sits substantially flush in the opening  35 ′ in the channel  3 , while the light unit  704   b  protrudes out of the opening  35 ′ (see  FIG. 36 ). 
     Furthermore,  FIGS. 33 and 35  in particular show how, in the region of ends of the light provision and optics unit  712   a  and  712   b  that are at the end faces thereof in the longitudinal direction L′, end faces  735  of the light units  704   a - b  may each end in an end cap  767 . In the case of a junction point  6  directly over the connector  5 , at this location end caps  767  may optionally be omitted or suitably adjusted in terms of their height. 
     Some profile bodies  7 ″″,  7 ′″,  7 ″ that may be used for the portions  2  of the channel  3  in a lighting system  1  according to the eighth embodiment are shown, by way of example, in  FIG. 33A  in partial images (a), (b) and (c). 
     In particular in the case of light units  104 ,  204 ,  304  and  604 , the housing component  121 ,  221 ,  321  and  621 , respectively, is not necessarily transparent, but may rather be opaque. A housing component that is either transparent or opaque is conceivable even in the light units  404 ,  504  and  704   a, b.    
     It is noted that the light units  4 ,  104 ,  104   a - b ,  204 ,  304 ,  404 ,  504 ,  604 ,  704   a - b  described above in relation to the embodiments may be used in combination in one of the channels  3  described above and also in lengths that are selected depending on the requirement and the channel length. This provides a wide range of possibilities for combination. Furthermore, the light units  4 ,  104 ,  104   a - b ,  204 ,  304 ,  404 ,  504 ,  604 ,  704   a - b  can each be inserted into channels  3  having different profile bodies  7 ,  7 ′,  7 ″,  7 ′″,  7 ″″. 
     By wirelessly switching and/or controlling the light output of the light units  4 ,  104 ,  104   a - b ,  204 ,  304 ,  404 ,  504 ,  604 ,  704   a - b , as provided in all of the above-described embodiments, simple operation of the lighting system and a particularly space-saving, slim structure are achieved. 
     The lenses  26 ,  126 ,  226 ,  326 ,  626  described above in relation to the embodiments allow for a shallow optical system, in particular in the depth direction T, and therefore contribute to a decrease in the space requirement and in particular in the installation depth of the channel  3 . Precisely the combination of a shallow power supply unit  11 , wireless control of the light units, the slim magnetic attachment solution for the light units, and the shallow connector  5  advantageously allows space and installation depth to be economised, while still allowing for highly aesthetic lighting solutions. 
     As the power supply unit  11  has the same structure in all the above-described embodiments, the structure of the lighting system can be simplified, and costs can be reduced, by standardising components. However, for different light units  4 ,  104 ,  104   a - b ,  204 ,  304 ,  404 ,  504 ,  604 ,  704 , the circuit board  37  may, if necessary or desired, be designed and/or populated in a manner suitable for the particular light unit, or may rather always be designed identically. 
     The magnetic attachment solution by means of permanent magnets  42  and the steel core  50  allows for fast, simple and reliable attachment of the light units  4  to  704  and low overall dimensions in all the above-described embodiments. 
     In all the above-described embodiments, light units having lengths L 4  of approximately L 4 =300 mm or approximately L 4 =600 mm or L 4 =1,200 mm or L 4 =1,800 mm or L 4 =2,400 mm, for example, may be provided, it being possible to assemble strip lights from a combination of light units  4  having different and/or the same lengths and a corresponding number of connectors  5 . While short light units  4  can manage with one power supply unit  11 , longer light units  4  may be provided with two or more power supply units  11 . The above observations concerning L 4  apply, accordingly, to the lengths L 104 , L 204 , L 304 , L 604  of the light units  104 ,  204 ,  304 ,  604 , respectively, and to the lengths of the light units  404 ,  504 ,  704   a - b . Lengths other than those mentioned above are also conceivable, for example approximately L 604 =500 mm. 
     If a strip light having a given, desired total length cannot be produced merely by combining light units  4 - 704  of several of the provided lengths, e.g. L 4 , L 104 , L 204 , L 304 , L 604 , it is possible, in any of the above-described embodiments, to better adjust the light units to the desired length by shortening the light provision and optics unit. For this purpose, the LED circuit board  24  can be cut at regular intervals. 
     For the above embodiments, the connector  5  is designed as a linear connector for coupling busbar portions  8  that are associated with straight portions  2  of the channel  3  that follow one another in a straight line. However, in a variant (not shown in the drawings), the connector  5  may be designed to electrically couple busbar portions  8  that are associated with straight portions  2  which follow one another in an angular manner. 
     In the lighting systems according to all the above-described embodiments, the channel  3  may, over shorter or longer sub-portions in the longitudinal direction thereof, not be fitted with the above-described light units  4 ,  104 ,  104   a - b ,  204 ,  304 ,  404 ,  504 ,  604  and/or  704   a - b , but rather one or more additional lighting inserts of different types may be inserted into the channel  3 . In this case, sub-portions of the channel  3  may even be left empty. The additional lighting inserts may be lighting inserts which, in the same way as the above-described light units  4 ,  104 ,  104   a - b ,  204 ,  304 ,  404 ,  504 ,  604  and/or  704   a - b , are supplied with current via the busbar  10  and of which the light output can be switched and/or controlled wirelessly, e.g. by means of a Zigbee. However, it may be that one or more of the additional lighting inserts is not designed to overlap the connector  5 . The additional light units may be designed, for example, as a spotlight, a pivotable spotlight, a suspended spotlight, a wallwasher, a linear arrangement of spotlights, a linear lighting insert that radiates in a diffused manner, or a pendant light fixture. 
     Although the present invention was described completely on the basis of various embodiments above, said invention is not limited thereto, but rather may be modified in a variety of ways. 
     For example, in addition to the magnetic attachment, the light unit could be designed to be additionally snap-fittingly or latchingly connected to the channel in a form-fitting manner. 
     Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. 
     In the foregoing and in the examples, all temperatures are set forth uncorrected in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated. 
     The entire disclosures of all applications, patents and publications, cited herein and of corresponding German application No. 10 2016 225 199.6, filed Dec. 15, 2016, are incorporated by reference herein. 
     From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.