EP1063468A1 - Lamp, in particular beacon light for air navigation height obstacles - Google Patents

Abstract

The lamps has two separable parts, a part (2) forming an electrical supply connection, which is fitted with a connecting cable (4) and plug, and a part (3) forming the light source, which has a cap (9) which can be coupled electrically and mechanically to the part (2). The electrical supply to the lamp is provided from a voltage transformer (8). The transformer (8) including its magnetic circuit forms two separate parts (8a,8b), a primary part (8a) and a secondary part (8b). The electrical connection between the cap (9) and the feed part (2) is assured by electromagnetic induction, without any direct contact. The part (2) has a body (6) made from an electrically insulating plastic. The part (9) is also made from an electrically insulating plastic. The body (6) and part (9) are fixed to each other via sensible plane contact surfaces (6a,9a). The primary part (8a) of the transformer is contained in plastic insulating material of the body (6) and the transformer secondary part (8b) is contained in the plastic material of the part (9) so that after connecting the two parts (6,9), the two parts (12a,12b) of the transformers (8) magnetic circuits form a sensibly closed magnetic circuit.

Description

The present invention relates to a lamp of the type comprising two separable parts, namely a part forming a power supply in electric current, which is provided with a power cord connectable to a source of electric current, and a part forming light source, which has a coupling base electrically and mechanically to the block part supply, the electrical energy required to operate the light source part being supplied thereto through a voltage transformer, said transformer, including its circuit magnetic, being made in two separate parts, namely a part primary and secondary part, the electrical coupling between the base and the power supply part being provided by induction electromagnetic, without any electrical contact.

The present invention relates in particular to a lamp of the type defined above, usable as beacon lamp, and more particularly still as a lamp for lighting roofs of buildings, pylons of a cable-stayed bridge or a bridge suspended or any other obstacle to air navigation in elevation.

Currently, beacon lamps of the type defined above are made up as follows. The block part power supply includes a metal case, usually in aluminum, which is made integral with a platform intended for support the beacon lamp and which contains the transformer tension mentioned above. The part forming a light source or lamp itself is plugged into this power supply. To this end, the lamp base, usually metallic, of the lamp has an axial pin which is electrically insulated from the metal base. Spindle axial can be engaged in a female housing which is provided in the upper surface of the metal housing of the power supply unit and which is electrically connected to the output of the voltage transformer. From a on the other hand, the metal base of the lamp is connected to earth by the metal case of the power supply unit on which it comes to bear. The lamp itself is, in known manner, made up of a tube cylindrical outer glass, surrounding a helical coil, in glass, each end of which contains an electrode. One of electrodes is electrically connected to the metal base which, in service, is grounded; the other electrode is electrically connected to the pin axial of the lamp. A thin cylindrical metal grid, placed against the inner wall of the outer glass tube acts as a Faraday.

The disadvantage of this known beacon lamp is that, in the As it is exposed to the weather, the contact area between the axial pin and the female housing in which said axial pin is introduced, is the seat of oxidation. This results in deterioration of the electrical contact with generation of parasites and even risk of solder between the spindle and its female housing. Another downside stems from the fact that if you remove the lamp (the source part of light) to change it, the female housing which is connected electrically at the transformer outlet is in the open air. Gold, the transformer output, when empty, is several kV. That constitutes, obviously a danger to maintenance personnel. Finally, the transformer contained in the power supply is a conventional transformer which has a high cost.

The present invention therefore aims to provide a lamp of the type defined above, in which the risks of oxidation above are deleted, so that the lamp can work properly even in aggressive environments.

The present invention also aims to provide a lamp of the type indicated above, which presents no danger to the personnel of maintenance when the lamp itself (the source part light) is removed for verification or replacement.

The present invention also aims to provide a lamp of the type indicated above, usable as beacon lamp, the transformer can be manufactured at a lower cost than that of the known beacon lamp described above.

a) la partie bloc d'alimentation a un corps en une matière plastique électriquement isolante ;

b) le culot est en une matière plastique électriquement isolante ;

c) ledit corps et ledit culot s'assemblent l'un à l'autre par des surfaces de contact sensiblement planes ;

d) la partie primaire du transformateur est noyée dans la matière plastique isolante dudit corps, et la partie secondaire est noyée dans la matière plastique isolante dudit culot de telle façon que, après accouplement mécanique du culot et du corps et assemblage de ceux-ci par leurs surfaces planes de contact, les deux parties du circuit magnétique associées respectivement auxdites parties primaire et secondaire du transformateur forment un circuit magnétique substantiellement fermé.

According to the invention, the first two objectives mentioned above are simultaneously achieved, in the lamp of the type defined in the preamble, by the fact that:

a) the power supply part has a body of electrically insulating plastic;

b) the base is made of an electrically insulating plastic material;

c) said body and said base are assembled to one another by substantially planar contact surfaces;

d) the primary part of the transformer is embedded in the insulating plastic material of said body, and the secondary part is embedded in the insulating plastic material of said base in such a way that, after mechanical coupling of the base and the body and assembly of these by their flat contact surfaces, the two parts of the magnetic circuit associated respectively with said primary and secondary parts of the transformer form a substantially closed magnetic circuit.

With such an arrangement, due to the total absence of contact electric between the two parts of the lamp, the risk of oxidation contacts that previously existed with the beacon lamp known, are totally eliminated. Furthermore, since there is no no electrical contact or other live metal parts which is exposed to the open air after uncoupling and removal of the part forming a light source, the lamp according to the invention does not have no danger for maintenance personnel.

The lamp according to the invention can, moreover, present the following features. In a preferred embodiment of the invention, said body and said base are cylindrical and have faces opposite each other, which are flat and at least approximately perpendicular to the longitudinal axis of said body and said cylindrical base. Under these conditions, the coupling mechanical between said body and said base can judiciously be made by screwing.

For this purpose, at their mutually adjacent ends, said body and said base made of insulating material can each be provided a metal outer socket. One of the two sockets protrudes beyond the corresponding end of the body or base and is threaded internally. The other sleeve is externally threaded and can be screwed into the internally threaded sleeve.

According to a preferred embodiment of the invention, each of the primary and secondary parts of said transformer can be formed by a coil placed in a cylindrical ferrite pot, with core central. The ferrite pot of the primary part and the ferrite pot of the secondary part have their openings which face each other and join edge to edge after mechanical coupling of said body and of said base. The transformer thus obtained is cheaper to manufacture than a conventional transformer.

Preferably, each metal socket has a dimension longitudinal such that its end furthest from the planar face end of said body or of said base is clearly beyond said transformer. Under these conditions, after screwing the two sockets metallic one inside the other, they form a kind of shielding which surrounds the transformer.

To obtain a good magnetic coupling between the two parts of the transformer, it is important to avoid an air gap forming between the front faces of the two ferrite pots and / or their core central when the flat contact surfaces of the base and the body are applied one against the other during the mechanical coupling of the pellet and body. This implies that said flat contact surfaces the base and the body are perfectly parallel to each other and perpendicular to the longitudinal axis of the two metal sockets. As this cannot be absolutely guaranteed due to tolerances of manufacture, it is then judicious that the part of said body which surrounds the ferrite pot of the primary part of said transformer either in a plastic material more flexible than that of the remaining part of said body, and / or to ensure that the part of said base which surrounds the pot in ferrite of the secondary part of said transformer either in a plastic material more flexible than that of the remaining part of said base. Under these conditions, when the flat contact surfaces of the body and of the base are pressed against each other when the two are screwed sockets one inside the other, a possible lack of parallelism of the two flat surfaces can be compensated by the flexibility of the material plastic of one and / or the other of the parts of the body and of the base which surrounds the corresponding primary or secondary part of the transformer.

In a preferred embodiment of the invention, the part light source may consist of a discharge lamp comprising, in a manner known per se, an inner glass tube, filled gas and sealed, a cylindrical metal grid, which surrounds coaxially said inner tube and forms a Faraday cage, and a outer cylindrical tube, made of glass, which coaxially surrounds said grid and which is open at its lower end and closed at its upper end by a dome-shaped part with nipple hollow central serving as a centering means for said inner tube in glass. As is also known, this inner tube can include a central cylindrical part, closed at its ends lower and upper, and a serpentine part which surrounds helically said central cylindrical part and the end of which lower is closed, while its upper end is connected to the central cylindrical part and communicates with it near the upper end thereof, which is extended upwards by an appendage engaged in the hollow stud of the dome of the tube cylindrical outer. In the lamp according to the invention, the ends lower of said inner cylindrical part, of said part in coil, said grid and said outer cylindrical tube are embedded in the plastic of said base.

Preferably, the cylindrical grid extends down to inside the metal socket of said base.

The lamp according to the invention may further comprise a first printed circuit board, which is embedded in the material plastic of said body, and a second printed circuit board, which is embedded in the plastic of said base, between the part secondary of said transformer and the lower ends of said inner cylindrical part and said serpentine part of the tube glass interior, which contain the electrodes of the lamp dump.

In a preferred embodiment of the invention, the first printed circuit board carries a bistable relay having two contacts mobiles mechanically coupled to each other, namely a first movable contact which is closed during normal lamp operation and a second movable contact which is open during normal operation of the lamp and which is connected to an external remote alarm circuit, a electronic chopping device and power regulator, a device rectification and filtering electronics, the input side of which alternating current is electrically connected to said power cord to through the first movable contact of the bistable relay, and whose side DC output is electrically connected to the coil of the part primary of said transformer via an output stage of said electronic chopper and power regulator.

The first printed circuit board can also carry a first voltage threshold device which is electrically connected to the coil of the primary part of said transformer and said bistable relay and which, when it detects that the voltage on said coil exceeds one first predefined voltage threshold, sends a trigger signal to the bistable relay to open its first mobile contact and close its second mobile contact.

The first printed circuit board can also carry a second voltage threshold device, which is electrically connected to the side alternating current input from the electronic rectifier and filtering and said bistable relay and which, when it detects that the voltage alternative power drops below a second threshold of predefined voltage, lower than the first voltage threshold, sends a trigger signal to the bistable relay to open its first mobile contact and close his second mobile contact.

The second printed circuit board can carry a capacitor which is electrically connected on the one hand to one of the ends of the coil of the secondary part of said transformer and, on the other hand, to one of the electrodes of the discharge lamp, the other electrode of said discharge lamp being electrically connected by a conductive track of the printed circuit of the second circuit board printed on the other end of the coil of the abutment of said transformer.

The discharge lamp can be designed to emit light red to be able to serve as beacon lamp to be installed at the top an obstacle to elevated air navigation.

• la figure 1 est une vue en perspective de la lampe selon l'invention ;
• la figure 2 est une vue en coupe verticale de la lampe de la figure 1, représentée à plus grande échelle, des parties de la lampe non utiles pour la compréhension de l'invention ayant été arrachées pour réduire la hauteur de la lampe dans cette figure ;
• la figure 3 est une vue en coupe verticale montrant, à une échelle encore plus grande, la partie supérieure (la partie formant source de lumière) de la lampe, ainsi qu'un moule pour la fabrication du culot en matière plastique de ladite lampe ;
• la figure 4 est une vue en coupe verticale, à la même échelle que la figure 3, montrant, à l'état renversé, la partie inférieure (la partie formant bloc d'alimentation) de la lampe selon l'invention, ainsi qu'un moule pour la fabrication du corps en matière plastique de cette partie de la lampe ;
• la figure 5 est une vue en perspective, avec arrachement, montrant certains des éléments de la partie bloc d'alimentation de la lampe, le corps en matière plastique ayant été enlevé ;
• la figure 6 est un schéma électrique fonctionnel montrant un ensemble de circuits qui sont portés par une plaquette à circuit imprimé logée dans le corps de la partie bloc d'alimentation de la lampe pour l'alimentation de la bobine primaire du transformateur de la lampe ;
• la figure 7 est un schéma du circuit électrique porté par une plaquette à circuit imprimé logée dans le culot de la partie source de lumière de la lampe.

Other characteristics and advantages of the present invention will emerge more clearly during the following detailed description of an embodiment of the lamp which is given by way of example with reference to the appended drawings in which:

• Figure 1 is a perspective view of the lamp according to the invention;
• Figure 2 is a vertical sectional view of the lamp of Figure 1, shown on a larger scale, parts of the lamp not useful for understanding the invention having been cut away to reduce the height of the lamp in this figure ;
• Figure 3 is a vertical sectional view showing, on an even larger scale, the upper part (the light source part) of the lamp, as well as a mold for the manufacture of the plastic base of said lamp;
• FIG. 4 is a view in vertical section, on the same scale as FIG. 3, showing, in the inverted state, the lower part (the part forming a power supply unit) of the lamp according to the invention, as well as a mold for manufacturing the plastic body of this part of the lamp;
• Figure 5 is a perspective view, broken away, showing some of the elements of the power supply part of the lamp, the plastic body having been removed;
• FIG. 6 is a functional electrical diagram showing a set of circuits which are carried by a printed circuit board housed in the body of the lamp power supply part for supplying the primary coil of the lamp transformer;
• Figure 7 is a diagram of the electrical circuit carried by a printed circuit board housed in the base of the light source part of the lamp.

The lamp 1 shown in Figures 1 and 2 includes a lower part 2 and an upper part 3. The lower part 2 constitutes an electric power supply unit and is provided, at this effect, a power cord 4 can be terminated by a plug 5 which can be plugged into a connected socket, for example, at the 220 V, 50 Hz sector. The lower part 2 of the lamp 1 has a body 6 of plastic, for example polyurethane, which can be fixed by suitable means, by example of the fixing collars, to a support (not shown), by example a pole or a mast fixed on the roof of a building.

The upper part 3 of the lamp 1 constitutes the source of light or lamp proper. It can be made up of a discharge lamp 7 which receives the electrical energy necessary for its operation through a voltage transformer 8 (Figure 2). The discharge lamp 7 is provided with a base 9 which can be coupled electrically and mechanically at the lower part 2 of the lamp 1.

According to the present invention, the electrical coupling between the upper part 3 and the lower part 2 of the lamp 1 are made in a special manner which will now be described.

As already indicated above, the body 6 of the lower part 2 is made of a plastic material, for example polyurethane, and it preferably has a cylindrical shape, with an end face upper 6a which is at least substantially planar and perpendicular to the longitudinal axis of the cylindrical body 6. Similarly, the base 9 is made of a plastic, for example polyurethane and it has, preferably a cylindrical shape, with an end face lower 9a which is at least substantially planar and perpendicular to the longitudinal axis of the cylindrical base 9. In service, the faces end 6a and 9a of the body 6 and the base 9 are mutually contact.

According to the invention, the transformer 8 is made in two parts separated, namely a primary part 8a and a secondary part 8b which are embedded respectively in the plastic of the body 6 and in the plastic material of the base 9.

Preferably, each of the primary and secondary parts 8a and 8b of the transformer 8 is constituted by a coil 11a or 11b, which is placed in a cylindrical pot 12a or 12b made of ferrite, fitted with a central core 13a or 13b. The pot 12a is embedded in the plastic of the body 6 so that the edge of the opening of the pot 12a and the front face of its central core 13a are flush with the face upper end 6a of the body 6 and centered relative to this face, as we will see later. Similarly, the pot 12b is embedded in the plastic material of the base 9 so that the edge of its opening and the front face of its central core 13b are flush with the face lower end 9a of base 9 and centered with respect to this way in a manner which will be described later.

Under these conditions, when the base 9 and the body 6 are mechanically coupled to each other, face 9a against face 6a, by coupling means which will be described later, the two pots 12a and 12b join edge to edge and their central cores 13a and 13b are join front face against front face, so as to form a substantially closed and continuous magnetic circuit.

The primary coil 1a is connected to the power cord 4 by through circuits which will be described in detail later and which are carried by a printed circuit board 14a also embedded in the plastic of the body 6. On the other hand, the coil secondary 11b is connected to the discharge lamp 7 by circuits which will be described in detail later and which are carried by another printed circuit board 14b also embedded in the material plastic base 9.

Under these conditions, when the lower part 2 and the part upper 3 of lamp 1 are mechanically coupled one to the other, the discharge lamp 7 is functionally coupled to the part lower 2 forming electromagnetic induction power pack through the two parts 8a and 8b of the transformer 8, without any electrical contact.

In order to avoid that, during the mechanical coupling of the two lamp parts 2 and 3 1, it does not form between the two pots 12a and 12b an air gap which could be due to a lack of parallelism of the faces end 6a and 9a, the part 6b of the body 6 which surrounds the pot 12a, or the part 9b of the base 9 which surrounds the pot 12b, preferably the two parts 6b and 9b are made of a softer plastic than that of the remaining part of the body 6 or of the base 9, for example of a resin silicone. However, given that parts 6b and 9b have a thickness, measured in the radial direction, significantly smaller than that of the remaining part of the body 6 or of the base 9, it is not absolutely essential that part 6b and / or part 9b is in a material softer than the material of the remaining part of the body 6 or of the base 9 if the latter material is both rigid enough to ensure good mechanical strength of the body 6 or of the base 9, while allowing slight displacements of one or the other of the two pots 12a and 12b by elastic deformation of the plastic when the two pots 12a and 12b are pressed against each other.

For the mechanical coupling of the two parts 2 and 3 of the lamp 1, body 6 and base 9 are each provided with a socket metallic 15 or 16, for example stainless steel, which can assemble to each other by screwing. One of the two sockets 15 and 16, e.g. socket 16, protrudes beyond the end bottom 9a of the base 9 and is provided with an internal thread. In this case, the other socket 15 is provided with an external thread and can be screwed into socket 16, as shown in figure 2. It will however of course we could have the opposite arrangement, that is to say that the body 6 could carry the female socket 16 and the base 9 could carry the male socket 15. In any case, the two sockets 15 and 16 preferably have a longitudinal dimension such that their end furthest from face 6a or 9a of body 6 or base 9 is clearly beyond transformer 8. So after assembly of the two sockets 15 and 16, these form a sort of shielding around the transformer 8.

The discharge lamp 7 comprises, in a manner known per se, a inner tube 17, made of glass, filled with gas and sealed, a grid cylindrical metal 18, which coaxially surrounds the inner tube 17 and forms a Faraday cage, and an outer cylindrical tube 19, in glass, which coaxially surrounds the grid 18. The outer tube 19 is open at its lower end 19a and closed at its end upper part by a dome-shaped part 19b, which has a stud hollow center 19c serving, as will be seen below, as a means of centering for the inner tube 17.

The inner tube 17 itself comprises a cylindrical part central 17a, which is closed at its lower and upper ends, and a serpentine part 17b, which helically surrounds said part central cylindrical 17a. The lower end of the coil 17b is closed and contains one 21 of the two electrodes 21 and 22 of the discharge lamp 7, the other electrode 22 (not shown in the Figure 2, but visible in Figure 7) being housed in the end closed bottom of the central cylindrical part 17a of the inner tube 17. The upper end of the serpentine part 17b is connected to the central cylindrical part 17a near the upper end of it and it communicates with it. The upper end of the central cylindrical part 17a is extended upwards by a appendix 17c which engages in the hollow stud 19c of the dome 19b of the outer cylindrical tube 19. Appendix 17c is capped by a shim mechanical 23 in the shape of a frustoconical hat, which gets stuck the interior of the hollow stud 19c, thus ensuring the centering of the tube inner 17 relative to the outer tube 19. The upper end of the metallic cylindrical grid 18 is sandwiched between the wedge 23 and the internal wall of the hollow stud 19c. The lower ends of the central cylindrical part 17a, of the serpentine part 17b, of the grid 18 and the outer cylindrical tube 19 are embedded in the material plastic of the base 9. The grid 18 extends downwards to the interior of the socket 16, as shown in FIG. 2.

The two electrodes 21 and 22 of the discharge lamp 7 are electrically connected by conductors 24 and 26 respectively to terminals 27 and 28, for example screw and nut terminals, carried by the printed circuit board 14b (only the conductor 24 and the terminal 27 are shown in Figure 2, but conductor 26 and terminal 28 are visible in figure 7). The two ends 29 and 31 (Figure 3) of the wire conductor forming the secondary coil 11b are connected respectively at terminals 32 and 33 (figure 7) of the circuit board printed 14b. Terminals 32 and 33 can be, for example, formed by metallized areas of the printed circuit of the wafer 14b, to which the conductors 29 and 31 are welded. Similarly, the ends 34 and 35 (Figures 4, 5 and 6) of the conductor forming the coil primary 11a are connected, for example soldered, to terminals or metallized areas 36 and 37 of the printed circuit of the wafer 14a.

We will now describe, with reference to FIG. 3, how the upper part 3 of the lamp 1 can be made. We first put the secondary coil 11b in the ferrite pot 12b while removing the conductors 29 and 31 through a lateral slot (or two side slots) of said pot 12b. This side slot of the pot 12b is not shown in the drawings, but may be similar to the slot 38 (Figure 5) of the pot 12a. Then put the pot 12b, in the state overturned, on the flat upper surface of a threaded cylindrical boss 39 of a plate 41, while centering the pot 12b relative to the boss 39 thanks to a centering pin 42 which is provided in the center of the surface upper part of boss 39 and which engages in a hole or cavity provided in the front face of the central core 13b of the ferrite pot 12b. Then put around the pot 12b the socket 16 by screwing it on the threaded cylindrical boss 39 of the plate 41.

Then, we pour between the sleeve 16 and the pot 12b the resin intended to form the flexible plastic part 9b of the base 9, until the pot 12b is completely covered with resin. We then let the resin harden at least partially and put on its upper surface the printed circuit board 14b provided with a crosspiece 43 so that it can balance. Then we do the connection (welding) of the conducting wires 29 and 31 of the coil 11b to the wafer 14b. Then bring the inner tube 17 of the lamp to discharge 7 above the printed circuit board 14b and on connect the conductors 24 and 26 of the lamp to terminals 27 and 28 of the printed circuit board 14b.

Then, place the outer tube 19, lined internally with the grid 18, around the inner tube 17, while penetrating the grid 18 in the socket 16, so that the bottom of said grid just arrives above the crosspiece 43. Then, around the sleeve 16 is placed a cylindrical mold 44 whose length is greater than that of the bush 16, so that this cylindrical mold 44 surrounds the part bottom of the outer tube 19 of the discharge lamp 7.

An annular space is thus obtained between this mold 44 and the tube exterior 19. While the latter is held by a support suitable (not shown) such that its lower end 19a is slightly spaced axially from the upper end of the sleeve 16, resin is poured into the aforementioned annular space and the resin rises inside the outer tube 19 in order to form the base 9 of the discharge lamp 7. The resin is poured until the lower ends of the central part 17a and the serpentine part 17b which contain the electrodes 21 and 22 of the discharge lamp are embedded in the resin.

The level of the resin inside the outer tube 19 of the discharge lamp 7 is below the level reached by the resin at the outside of said tube. This is due to the fact that when we pour the resin by simple gravity, the resin which rises inside the tube 19 compresses the air trapped in this tube, and the air pressure opposes the rise of the resin in the tube.

When the resin is set, we remove the cylindrical mold 44 and we unscrews the sleeve 16 to separate it from the threaded cylindrical boss 39 of the plate 41. The upper part 3 of the lamp 1 is then obtained according to the invention.

The lower part 2 of the lamp 1 according to the invention can be performed in a manner similar to that described above at About the top 3. Specifically, referring to the FIG. 4, the sub-assembly constituted by the primary coil 11a and by the 12a ferrite pot is first placed on the flat bottom of a cavity circular 45 formed in the surface of a plate 46, which can be possibly the same plate as the plate 41 of FIG. 3 or a other tray. The cavity 45 is threaded on its inner contour and has, in the center of its flat bottom, a centering pin 47 by means from which the pot 12b can be centered in the cavity 45.

Then place the socket 15 around the pot 12b by screwing it into the cavity 45. Then, resin is poured between the sleeve 15 and the pot 12a until the resin completely covers the pot 12a, so as to form the flexible plastic part 6b of the body 6. Then let the resin harden at least partially and place on its upper surface the printed circuit board 14a which has been connected to the power cord 4 and provided with a cross 48 (see also FIG. 5) by which the plate 14a can hold in balance on the resin forming the part 6b of the body 6.

Next, the conducting wires 34 and 35 of the primary coil 11a are connected (soldered) to the printed circuit board 14a, then a cylindrical mold 49 is placed around the sleeve 15. The mold 49 has a substantially greater axial length than that of the sleeve 15, so that when it is supported by its lower end on the tray 46, its upper end is at a higher level as the upper end of the printed circuit board 14a. We resin is then poured into the mold 49 until it is completely filled and that the printed circuit board 14a thus that part of the power cord 4 are embedded in the resin. When the latter has set, remove the mold 49 and unscrew the sleeve 15 in order to detach it from the plate 46. We then obtain the part lower part of the lamp 1 according to the invention.

In the embodiment described above, the flexible resin was poured around each of the two ferrite pots 12a and 12b, but we could only plan around one of the two ferrite pots.

We will now describe the circuits carried by the two printed circuit boards 14a and 14b, with reference to the figures 6 and 7. As shown in FIG. 6, the plate 14a carries a electronic rectifying and filtering device 51, the side of which AC input is connected, on the one hand, directly to a terminal 52 and, on the other hand, via a first contact mobile 53 from a bistable relay 54, to another terminal 55. The two wires of the power cord 4 are connected to terminals 52 and 55. If the power cord has a third wire, for example a earth, the plate 14a may comprise, next to the two terminals 52 and 55, another terminal for the connection of this earth wire.

The DC output side of the electronic device rectification and filtering 51 has a positive pole which is connected directly to terminal 36 already mentioned above, and a negative pole which is connected on the one hand to earth and on the other hand to terminal 37 already mentioned more high, via a shunt resistor 57 and the source-drain path of a field effect transistor 58, connected in series. In normal operation of lamp 1, moving contact 53 of the relay bistable 54 is closed, so that the primary coil 11a of the transformer 8 is supplied with current through the device rectification and filtering electronics 51, resistor 57 and source-drain path of the field effect transistor 58. This transistor 58 constitutes the output stage of a chopping electronic device and power regulator 59 which keeps the chopped current constant circulating in the primary coil 11a whatever the value of the alternating input voltage (between 150 and 280 V approximately). These measures electronics 59 includes an operational amplifier 61 in series with a converter 62 passing from a direct current to a pulsed current at 25 kHz. The two amplifier inputs operational 61 are connected respectively to point 63 on the side input of the electronic rectifying and filtering device 51 and at point 64 between the shunt resistor 57 and the transistor 58. The output of the converter 62 is connected to the trigger of transistor 58.

The printed circuit board 14a further carries a first voltage threshold device 65, the input of which is connected at point 66 between terminal 37 and transistor 58, and whose output is connected to a first control input 67 of the bistable relay 54. The voltage threshold device 65 monitors the voltage on the coil primary 1 la of transformer 8 in order to detect if it is not too big. Indeed, too much tension at point 66 reveals that the discharge lamp 7 is missing or defective. If the voltage at point 66 reaches or exceeds a first predefined voltage threshold, for example 600 V, the voltage threshold device 65 acts on the bistable relay 54 in order to cause the opening of its first movable contact 53 and, simultaneously closing a second mobile contact 68 of the relay bistable, which is mechanically connected to the first movable contact 53. Thus, the supply current of the discharge lamp 7 is cut by contact 53 so as not to leave the circuit energized, which constitutes additional security for maintenance personnel, and also so as not to have to oversize the components in because of the voltages reached in the absence of a lamp, voltages which can reach 1 kV. Simultaneously, at the opening of the first mobile contact 53, the second mobile contact 68 closes a circuit remote alarm to signal the detected fault. The two sons 69 of this external remote alarm circuit are connected respectively at terminals 71 and 72 of the printed circuit board 14a and they can be included in the same cord as the cord wires 4, or in a separate cord from the power cord 4.

The printed circuit board 14a further carries a second voltage threshold device 73 whose input is connected at point 63 mentioned above and whose output is connected to a second input of command 74 of the bistable relay 54. This second device with a threshold of voltage 73 is intended to detect whether the alternating supply voltage drops below a second predefined voltage threshold, for example 140 V, and, if this happens, it causes contact 53 to open and the contact 68 of relay 54 closed. Indeed, a discharge lamp such as the discharge lamp 7 described above malfunctions if the alternating supply voltage drops below a certain voltage value and in this case it is also desirable to cut the lamp supply current and report this fault.

Relay 54 is a bistable relay, as already indicated, so it must be reset when a fault has been detected. This can be done by cutting off the power supply for a few seconds, for example using a on / off (not shown) located in the upstream supply circuit of sheet 5.

As shown in Figure 7, the printed circuit board 14b carries a capacitor 75, the armatures of which are connected respectively at terminals 27 and 32 already mentioned above, as well a conductive track 76 which directly connects the terminals 28 and 33 already mentioned above.

In the embodiment which has been described above, the lamp with discharge 7 can be, for example, a lamp filled with a gas such as the lamp emits red light when it is switched on, so so that the lamp can be used as a beacon lamp to be installed by example on the roof of a tall building or at the top of any other obstacle to elevated air navigation.

As an indication, the primary coil 11a has an outside diameter of 30 mm and it has 54 turns of conductive wires of 30/100 mm of diameter. The secondary coil 11b has the same outside diameter and it can include 329 turns in conductive wires of 12.5 / 100 mm diameter.

It is, of course, moreover, that the embodiment which has been described above was given as a purely indicative example and in no way limitative, and that many modifications can be made by those skilled in the art without departing from the scope of the invention. Thus, in particular, instead of coupling mechanically the two parts 2 and 3 of the lamp 1 by sockets metal 15 and 16 respectively male and female can be screwed one inside the other, the mechanical coupling could be for example produced by sockets fitted with flanges or flanges which can be fixed to each other by bolting. Furthermore, although this invention has been more particularly described with regard to a lamp beaconing, it applies to any other lamp which is supplied with current through a transformer and which is intended to be used in outside or in an environment where an aggressive atmosphere prevails.

Claims (15)

Lamp comprising two separable parts, namely a part (2) forming an electric power supply unit, which is provided with a power cord (4) connectable to a source of electric current, and a part (3) forming light source, which comprises a base (9) which can be electrically and mechanically coupled to the part (2) forming a power supply, the electrical energy necessary for the operation of the light source part being supplied to the latter through a voltage transformer (8), said transformer (8), including its magnetic circuit, being produced in two separate parts (8a, 8b), namely a primary part (8a) and a secondary part (8b), the electrical coupling between the base (9) and the power supply part (2) being provided by electromagnetic induction, without any electrical contact,
characterized by the fact that: a) the power supply part (2) has a body (6) made of an electrically insulating plastic material; b) the base (9) is made of an electrically insulating plastic material; c) said body (6) and said base (9) are assembled to one another by substantially planar contact surfaces (6a, 9a); d) the primary part (8a) of the transformer is embedded in the insulating plastic material of said body (6), and the secondary part (8b) is embedded in the insulating plastic material of said base (9) in such a way that, after mechanical coupling of the base (9) and of the body (6) and assembly of these by their flat contact surfaces (6a, 9a), the two parts (12a, 12b) of the magnetic circuit associated respectively with said primary and secondary parts of the transformer ( 8) form a substantially closed magnetic circuit. Lamp according to claim 1, characterized in that said body (6) and said base (9) are cylindrical and have faces end (6a, 9a) mutually opposite one another, which are flat and at least substantially perpendicular to the longitudinal axis said body and said cylindrical base, and by the fact that the coupling mechanical between said body (6) and said base (9) is effected by screwing. Lamp according to claim 2, characterized in that, at their mutually adjacent ends, said body (6) and said base (9) in insulating material are each provided with an outer sleeve metallic (15 or 16), one (16) of the two sockets projecting beyond of the corresponding end of the body (6) or of the base (9) and being internally threaded, while the other sleeve (15) is threaded externally and can be screwed into the threaded sleeve (16) internally. Lamp according to claim 2 or 3, characterized in that that each of the primary (8a) and secondary (8b) parts of said transformer (8) consists of a coil (11a or 11b) placed in a ferrite cylindrical pot (12a or 12b), with central core (13a or 13b), the ferrite pot (12a) of the primary part (8a) and the pot (12b) in ferrite of the secondary part (8b) having their openings which are made face each other and join edge to edge after mating mechanical of said body (6) and said base (9). Lamp according to claim 4, characterized in that each metal socket (15, 16) has a longitudinal dimension such that its end furthest from the flat end face (6a or 9a) of said body (6) or of said base (9) is clearly beyond said transformer (8). Lamp according to claim 4 or 5, characterized in that that the part (6b) of said body (6) which surrounds the pot (12a) of ferrite the primary part (8a) of said transformer (8) is made of a material plastic more flexible than that of the remaining part of said body (6). Lamp according to any one of Claims 4 to 6, characterized in that the part (9b) of said base (9) which surrounds the ferrite pot (12b) of the secondary part (8b) of said transformer (8) is made of a softer plastic than that of the remaining part of said base (9). Lamp according to any one of Claims 3 to 7, characterized in that the light source part (3) consists by a discharge lamp (7) comprising an inner tube (17) in glass, filled with gas and sealed, a cylindrical metal grid (18), which coaxially surrounds said inner tube (17) and forms a cage of Faraday, and an outer cylindrical tube (19) made of glass, which surrounds coaxially said grid (18) and which is open at its end lower and closed at its upper end by a part (19b) in dome shape with hollow central stud (19c) serving as a means of centering for said inner tube (17) made of glass, this inner tube comprising a central cylindrical part (17a) closed at its lower and upper ends, and a serpentine part (17b) which helically surrounds said central cylindrical part (17a) and of which the lower end is closed, while its upper end is connected to the central cylindrical part (17a) and communicates with it near the upper end of it, which is extended upwards by an appendage (17c) engaged in the hollow stud (19c) of the dome (19b) of the outer cylindrical tube (19), and by the fact that the lower ends of said central cylindrical part (17a), of said serpentine part (17b), said grid (18) and said tube cylindrical outer (19) are embedded in the plastic of said base (9). Lamp according to claim 8, characterized in that the cylindrical grid (18) extends down to the interior of the metal bush (16) of said base (9). Lamp according to claim 8 or 9, characterized in that that it comprises a first printed circuit board (14a), which is embedded in the plastic of said body (6), and a second printed circuit board (14b) which is embedded in the material plastic of said base (9), between the secondary part (8b) of said transformer (8) and the lower ends of said part inner cylinder (17a) and said serpentine part (17b) of the inner tube (17) made of glass, which contain the electrodes (21 and 22) of the discharge lamp (7). Lamp according to claim 10, characterized in that the first printed circuit board (14a) carries a bistable relay (54) having two movable contacts (53 and 68) mechanically coupled to each other, namely a first movable contact (53) which is closed at normal operation of the lamp (7) and a second movable contact (68) which is open during normal operation of the lamp (7) and which is connected to an external remote alarm circuit (69), a device electronic chopper and power regulator (59), a device rectification and filtering electronics (51), the input side of which alternating current is electrically connected to said power cord (4) through the first movable contact (53) of the bistable relay (54), and the DC output side of which is electrically connected to the coil (11a) of the primary part (8a) of said transformer (8) by via an output stage (58) of said electronic device chopper and power regulator (59). Lamp according to claim 11, characterized in that the first printed circuit board (14a) further carries a first voltage threshold device (65) which is electrically connected to the coil (11a) of the primary part (8a) of said transformer (8) and said relay bistable (54) and which, when it detects that the voltage on said coil (11a) exceeds a first predefined voltage threshold, sends a signal triggering at the bistable relay (54) to open its first contact mobile (53) and close its second mobile contact (68). Lamp according to claim 11 or 12, characterized by causes the first printed circuit board (14a) to further carry a second voltage threshold device (73) which is electrically connected to the AC input side of the electronic device rectification and filtering (51) and to said bistable relay (54) and which, when it detects that the AC supply voltage drops to below a second predefined voltage threshold, lower than the first voltage threshold, sends a trigger signal to the bistable relay (54) to open its first mobile contact (53) and close its second mobile contact (68). Lamp according to any one of claims 10 to 13, characterized in that the second printed circuit board (14b) carries a capacitor (75) which is electrically connected on the one hand to a (32) of the ends (31,32) of the coil (11b) of the abutment (8b) of said transformer (8) and, on the other hand, to one (21) of the electrodes (21 and 22) of the discharge lamp (7), the other electrode (22) of said discharge lamp being electrically connected by a conductive track (76) of the printed circuit of the second printed circuit board (14b) at the other end (31) of the coil (11b) of the secondary part (8b) of said transformer (8). Lamp according to any one of Claims 8 to 14, characterized in that the discharge lamp (7) emits light red and serves as a beacon lamp to be installed at the top of an obstacle to elevated air navigation.

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