FR2822586A1 - OVER-MOLDED HIGH-VOLTAGE ELECTRIC TRANSFORMER - Google Patents

Abstract

An overmolded high-voltage electrical transformer comprises a molded resin body (10) provided with connection terminals for a primary circuit (14-17) and connection terminals for a secondary circuit (13, 18) of the transformer. comprises a connection module (20) adapted to connect an electrical supply cable to the connection terminals of the primary circuit (14-17) and a protective cover (30) separate from the connection module (20) and comprising detachable means The connection module (20) includes indicator lights (23, 24) adapted to indicate the presence of an electrical voltage respectively on the primary and secondary circuits of the transformer, and the cover ( 30) comprises display means (33, 34) of the indicator lights. Use in particular to power an electro-luminescent tube of a light sign.

Description

a corresponding relief (63, 64, 65, 66) produced on the pallet (58).

  The present invention relates to a high electrical transformer

overmolded tension.

  In particular, it targets high-voltage transformers used to power the electroluminescent tubes fitted to the illuminated signs. These electrical transformers are generally placed outside, high up on a facade of a building, and must therefore

  weatherproof and waterproof.

  The electrical transformers targeted by the present invention are of the overmolded type, that is to say that they comprise a molded resin body.

  in which the transformer windings are incorporated.

  This molded resin body is provided with connection terminals allowing both the connection to the primary circuit of the transformer, that is to say the low-voltage power cable of the transformer, and to the secondary circuit of the transformer, this is ie to the output cables intended to supply high-voltage current to an electrical device such as a light tube. Generally, the connection of the power cable is carried out through a connection module secured to a protective cover. This protective cover covers all of the connections at one end of the body

in molded resin.

  The connection module generally incorporates various safety cut-off elements which allow the electrical supply to be automatically cut off at the primary circuit level in the event of incorrect installation of the transformer and its protective cover or during

  The appearance of electrical faults on the circuit.

  However, such a transformer structure requires, at the time of its electrical connection, the production on the one hand of the c .. connections of the primary circuit to the connection module fixed to the cover of the transformer, and on the other hand, circuit connections secondary level

of the transformer.

  The object of the present invention is to solve the aforementioned drawbacks and to propose an electric transformer which is particularly simple to install and which offers safety guarantees during all operations.

  installation and maintenance of the transformer.

  The overmolded high-voltage electrical transformer targeted by the invention comprises a molded resin body provided with connection terminals of a primary circuit and connection terminals of a circuit

secondary of the transformer.

  In accordance with the invention, the high-voltage electrical transformer

  overmolded voltage includes a connection module suitable for connecting an electric power cable to the connection terminals of the main circuit and a cover separate from the connection module and comprising detachable fixing means to the transformer, the connection module comprising indicator lights adapted to indicate the presence or absence of an electrical voltage respectively on the primary and secondary circuits of the transformer and the cover comprising means for displaying the indicators

luminous.

  Thanks to the independent cover of the connection module and detachably mounted on the transformer, the connection module can be mounted separately from the cover on the molded resin body so that all the connections of the primary and secondary circuits of the transformer

  can be performed directly at the transformer.

  The protective cover can be removed independently of the connection module of the primary circuit, indicator lights judiciously allow to indicate to the operator the presence or not of an electric voltage on the primary and secondary circuits of the transformer before all

  interventions on this transformer.

  These indicator lights are arranged opposite the cover viewing means allowing the operator to view the state of the

  transformer before opening this one.

  The overmolded high-voltage electrical transformer according to the invention thus allows easy and safe mounting of the transformer on

the electrical network.

  According to a preferred characteristic of the invention, the cover comprises

  thin transiucid portions facing the indicator lights.

  The transformer cover is thus perfectly sealed opposite the indicator lights, only portions of the cover, for example made of transiucid plastic, being thinned in order to ensure the transmission of the light emitted.

  by the connection module LEDs.

  According to another preferred characteristic of the invention, ie connection module integrates cut-off elements of the electrical supply adapted to cooperate with complementary cut-off elements secured to the cover. It is thus possible to automatically cut the power supply to the transformer when removing the cover, especially during an operation of

transformer maintenance.

  According to another preferred characteristic of the invention, the connection module further comprises an electronic protection device adapted to establish a cut in the electrical supply when a

  differential voltage, and possibly a no-load voltage.

  Thanks to the indicator lights on the connection module thus equipped with an electronic protection device, it is possible to detect the operation of the electronic protection when a fault occurs.

  (earth leakage, broken luminescent tube, ...).

  Other features and advantages of the invention will appear.

  again in the description below.

  In the appended drawings, given by way of nonlimiting examples: - Figure 1 is an exploded perspective view of an overmolded high-voltage electric transformer according to an embodiment of the invention; Figure 2 is a partial top view of the transformer of Figure 1 illustrating the electrical connections, the protective cover being removed; - Figure 3 is a bottom view of the protective cover of Figure 1; - Figure 4 is a partial cross-sectional view of the cover along the line IV-IV in Figure 3; - Figure 5 is a bottom view of the transformer assembly of Figure 1, after assembly; - Figure 6 is a side view of a shunt mounted on the protection module of Figure 2, in the absence of a flasher; - Figure 7 is a front view of the shunt of Figure 6; - Figure 8 is a top view similar to Figure 2 illustrating the wiring of a transformer with a flasher; and - Figure 9 is a perspective view of a connection module adapted to be mounted in a transformer according to a second mode

for carrying out the invention.

  We will first describe with reference to FIG. 1, an overmolded high-voltage transformer conforming to a first mode of

realization of the invention.

  This overmolded high-voltage electrical transformer includes a

molded resin body 10.

  It mainly comprises a base 10a of substantially parallelepiped shape. This overmolded body 10 incorporates the nocessar windings for the transformation of the low-voltage current into high-voltage current at the output of

this transformer.

  This molded resin body 10 is fixed to a rail 11 subsequently allowing the transformer to be fixed to the facade of a building by

example.

  At one end of this transformer, all the connection terminals are grouped allowing connection both at the level of the primary circuit

  than at the secondary circuit of the transformer.

  More specifically, the base 10a is extended to one of its

  ends by a wing 12 carrying the various connection terminals 1318.

  The body 10 of the transformer, thus formed of a base 10a and a wing 12 carrying the connections, is molded in one piece in a resin,

Epoxy resin type.

  The six connection terminals 13-18 are substantially aligned with

  the wing 12 in a transverse direction of the transformer.

  The two connection terminals 13, 18 situated at the ends of this alignment, are adapted to establish the connection of the secondary circuit of the transformer. As illustrated in FIG. 2, two output wires 1 3a, 18a are adapted

  to be connected to these two connection terminals 13, 18 of the secondary circuit.

  The other four central connection terminals 14-17 are

  suitable for establishing the connection at the primary circuit of the transformer.

  In order to make this connection of the primary circuit, a connection module 20 is used to connect an electrical power cable C to the

  transformer connection terminals 14-17.

  This connection module 20 is detachably mounted thanks to

  to screws 21, on the wing 12 of the molded resin body 10 of the transformer.

  The operation and connection of this module 20 will be described

  in more detail with reference to Figures 2 and 6 to 8.

  The electric transformer further comprises a protective cover 30 independent of both the connection module 20 and the body 10 of the transformer. This protective cover 30 is here made of a material

  transparent, and preferably polycarbonate.

  In order to achieve the removable attachment of this protective cover 30 to the transformer, it comprises detachable attachment means, which can

  conventionally consist of a fixing screw 31.

  In accordance with the invention, the connection module 20 further comprises indicator lights 23, 24 adapted to indicate the presence or absence of an electrical voltage respectively on the primary and secondary circuits of the transformer. These indicator lights can be made up of LEDS, for example a green LED indicating, when it is lit, the presence of an electric voltage on the primary circuit, and a red LED indicating, when it is lit, the presence an electrical voltage on the circuit

secondary of the transformer.

  The protective cover 30, covering the entire protection module 20 and the wing 12 of the transformer, includes display means 33,34 making it possible to display the state of the indicator lights 23,24

  from outside the transformer, through the protective cover 30.

  As illustrated in FIG. 3, these display means 33, 34 of the cover 30 here consist of two hemispherical portholes adapted to be

  positioned opposite the indicator lights 23,24.

  More precisely, with reference to FIG. 4, these portholes 33, 34 are produced by thin transiucid portions. By way of example, the plastic material of the cover 30 can be worked by lithophanie, making it possible to greatly reduce the thickness of the material at the level of the windows 33, 34, so that one can distinguish through these windows very clearly the

  23.24 indicator lights arranged below.

  As well illustrated in Figure 3, the cover 30 further comprises a

  magnet 35 fixed in the bottom of the cover 30.

  This magnet 35 is suitable for closing a switch of the connection module 20 when the cover 30 is placed in contact with the connection module 20. On the contrary, as soon as the cover 30 is removed, the distance from the magnet

  causes the connection module 20 switch to open.

  This magnet 35 thus forms a cut-off element, complementary to the cut-off element of the electrical supply integrated in the module.

connection 20.

  The switch (not shown) integrated in the protection module is a switch with a metal blade adapted to close under the effect of the field

  magnetic generated by the magnet 35.

  The removal of the transformer cover 30 thus automatically cuts off the electrical supply at the entrance

protection module 20.

  As illustrated in the exemplary embodiment of FIG. 2, here, the connection module 20 further comprises an electronic protection device suitable for establishing a cut in the electrical supply when a differential voltage is detected and possibly upon detection

no-load voltage.

  Such an electronic protection device is well known and can be integrated on a printed circuit card. It cuts the power supply to the transformer in the event of a fault on the high voltage circuit. More particularly, when a differential voltage is detected, for example in the event of an earth leakage from the electric current, a pure neck

  differential electric is operated in the connection module.

  When this connection module also comprises means for detecting a no-load voltage, an electrical vacuum cut-off is ensured, for example in the event of the transformer running dry, when a tube

  luminescent power supplied by the transformer is broken.

  The measurement of a reference voltage for the operation of this electronic protection device is carried out at the input of a

  connection terminal 1 7a (terminal L1) of connection module 20.

  In order to guarantee the tightness of the mounting of the cover 30 around the connection module 20 and of the various connection terminals of the transformer, this connection module 20 is integral with a seal 40 which makes it possible to close the free space 41 allowing the cable routing

  power supply C and output cables 13a, 18a outside the transformer.

  There is indeed a free space 41 between the wing 12 of the body of

  transformer carrying the connection terminals 13 to 18 and the cover 30.

  The seal 40 has a shape adapted to close off all of this space

free 41.

  It further comprises passage openings 42-45, here four in number, allowing the passage of the power cables C and the cables of

output 13a, 18a of the transformer.

  More particularly, two passage openings at the end of the joint allow the passage of the output cables 13a, 18a of the secondary circuit.

of the transformer.

  A third passage orifice 43 allows the passage of the power cable C and a fourth passage orifice 44 is suitable for the passage possibly of an additional cable 51 described later and used when the transformer is associated with a flashing light, and in the case a bypass, for example when adding a compensation capacitor. In order to facilitate the mounting of the cables, this seal includes, for each passage opening 42-45, a slot 42a-45a opening on the one hand into the passage opening 42-45 and on the other hand into a free edge 40a of the seal 40. Each of these slots 42a-45a is adapted to the passage of a power supply cable C or output 13a, 18a of the transformer so that these cables can be introduced into the through holes 42-45 after their respective connection on the connection terminals of the transformer and

connection module 20.

  In order to guarantee watertightness around the cables, each passage orifice 42-45 is preferably closed off by a cover pierced with an orifice and adapted to resiliently match the external body of each cable, whatever

whatever the diameter of the cable.

  As illustrated in FIG. 5, each of the slots 42a-45a is adapted to be kept closed on the free edge 40a of the seal 40 by a wing

  36 of the cover 30 which extends along the free edge 40a of the seal 40.

  The seal 40 thus extends between the wing 12 of the body 10 of the transformer and the wing 36 of the cover 30 so that the slots 42a-45a cannot open and allow the passage of the cables when the cover 30 is up on

the transformer.

  In addition, the cover 30 comprises at its end opposite the wing 36, a bearing edge 37 adapted to come into contact against the end wall 30b of the

base 30a, in front of wing 12.

  A covering wing 38 further extends from this support edge 37, perpendicular to this support edge 37, so as to come

  cover the base 10a over a certain length I (see FIG. 5) thereof.

  This ensures perfectly tight mounting of the cover 30 on

  The end of the base l Oa of the transformer.

  We will now describe a connection mode of the module

  connection 20 with reference to FIG. 2.

  A power cable C comprising a ground wire, a neutral wire and a phase wire is connected respectively to three connection terminals 14a, 15a, 16a of the connection module 20, these terminals 14a, 15a, 16a being electrically connected at the connection terminals 14, 15, 16 of the primary circuit provided

on the body 10 of the transformer.

  The terminal L1 in this arrangement, not being used, a part 25 producing an electrical shunt is disposed between the connection terminal of the wire

  phase 16a and the free terminal 17a (terminal L1).

  As illustrated in FIGS. 6 and 7, this shunt piece 25 includes a metal part 26 comprising two arms 26a, 26b adapted to be secured respectively to the connection terminals 16a, 17a, so as to

  establish an electrical connection between these two terminals 16a, 17a.

  This shunt piece 25 avoids wiring the two terminals of

connection 16a, 17a.

  This metal part 26 is integral with a support 27 made of a non-conductive material such as plastic. This support 27 comprises a wing 27a extending substantially perpendicular to the general plane of

the metal part 26.

  As illustrated in FIG. 2, when this shunt piece 25 is mounted between the connection terminals 16a, 17a of the connection module 20, this wing 27a extends in front of the free connection terminal 17a, substantially at

  level of the passage provided for a cable to be connected.

  This wing 27a thus forms a polarizing key and prevents the operator from connecting a wire to the free terminal 17a of the connection module 20 when the

shunt 25 is in place.

  As illustrated in FIG. 8, when the transformer is associated with a flasher 50, conventionally making it possible to sequentially power the transformer to create a flashing bulb in a light sign, the connection module 20 which is connected to the sector through the flasher 50 is also connected by a cable 51, connecting the terminal

  end 17a to the phase input terminal 52 of the flasher 50.

  In this connection mode, the cable 51 makes it possible to relate the value of the input voltage of the electric current to the terminal L1 of the connection module 20, on which the differential cover of the

  electronic protection device.

  In this case, of course, the shunt piece 25 is removed so that there is no electrical connection between the two terminals of

  connection 16a, 17a of the connection module 20.

  This shunt piece 25 thus makes it easy to switch from a connection mode without an igniting key as illustrated in FIG. 2 to a mode of connection.

  connection with flasher as illustrated in figure 8.

  In order to allow viewing of the status of the transformer, and of the connection module 20 integrating the electronic protection device, the first indicator light consists of an LED 23 indicating the voltage at the

  level of entry of cable C into connection module 20.

  The second indicator light consists of an LED 24 indicating the voltage at the output of the connection module 20, before the connection terminals

14-17 of the primary circuit.

  Thanks to the respective state of these indicator lights, a certain number of deductions can be made on the operation of the transformer. In particular, in normal operation of the transformer, the two LEDS 23, 24 must be lit when the cover 30 is correctly positioned on the

  transformer and connection module 20.

  When this cover is removed, the cut-off element cooperating with the magnet 35 cuts the electrical supply at the connection module so that the second indicator 24 is off, the first indicator 23

  remaining on as long as cable C remains connected to the mains.

  Any other configuration of the indicator lights, with or without the

  cover 30, is indicative of the presence of a fault on the transformer.

  In particular, if when the cover 30 is removed, the two indicator lights 23, 24 remain on, this means that the electric cut-off element cooperating with the magnet 35 has not operated in such a way that it is necessary to

change the connection module 20.

  If the two indicators remain off, with or without cover 30, this means that there is no voltage on the primary circuit and it is necessary to check the low-voltage installation of the transformer, and in particular the power supply to the level of cable C. On the other hand, if with the cover in the closed position, while the second indicator 24 is on, the first indicator 23 remains off, this means that this first indicator 23 no longer works and that it is necessary to change the

connection module 20.

  Conversely, if, although the cover is correctly positioned on the connection module 20, the second indicator light 24 remains off while the first indicator light 23 is correctly lit, this means that the

  electronic protection device worked, following a fault on the circuit.

  It is then necessary to rearm the entire system by a

  on-off operation of the mains power supply.

  It will be noted that if this rearming can be obtained by a simple removal and then replacement of the cover 30, this means that it is the part of the vacuum cut-off of the electronic protection device which has worked. The fault may correspond to a broken tube in the device supplied by the transformer. On the other hand, if the resetting of the electronic protection device requires the extinction then the re-ignition of the electrical sector, this means that the part of the differential cut of the protection device

  electronics worked, for example due to a current leak to earth.

  Thus, thanks to the arrangement of these indicator lights visible from the outside of the transformer through the cover 30, it is possible to know the operating state of the transformer and of its connection module 20,

without opening the cover 30.

  In the previous embodiment, an electrical transformer equipped with a connection module 20 comprising a device has been described.

electronic protection.

  Of course, in a second embodiment as illustrated in FIG. 9, the connection module can be replaced by a mechanical connection module 60 having dimensions substantially identical to

  those of the electronic connection module 20 described above.

  This mechanical connection module 60 is also associated with a

  joint 40 identical to that described in the previous embodiment.

  In this type of mechanical connection, the cover 30 cooperates with mechanical contacts 61, 62 projecting from the connection module 60 and adapted to be kept pressed in when the cover 30 comes to cover the

  connection module 60 to be fixed on the transformer.

  These mechanical contacts 61, 62 are mounted on the phase and the

  transformer power supply neutral.

  Indicator lights 63, 64 can also equip the mechanical connection module to indicate the presence of a voltage on the circuit

  primary or voltage on the secondary circuit in the transformer.

  Of course, many modifications can be made to the embodiments described above without departing from the scope of the invention.

Claims (7)

  1. Overmolded high-voltage electric transformer comprising a body (10) of molded resin provided with connection terminals of a primary circuit (14-17) and connection terminals of a secondary circuit (13, 18) of the transformer, characterized in that it comprises a connection module (20,) suitable for connecting an electrical supply cable (C) to the connection terminals of the primary circuit (14-17) and a protective cover (30) separate from the module connection (20, 60) and comprising detachable means of attachment (31) to the transformer, the connection module (20,60) comprising indicator lights (23, 24; 63, 64) adapted to indicate the presence of the 'an electrical voltage respectively on the primary and secondary circuits of the transformer, and the cover (30) comprising display means (33, 34) indicator lights.   2. High-voltage overmolded electrical transformer according to claim 1, characterized in that the cover (30) comprises transiucid portions (33, 34) of small thickness opposite the indicator lights (23, 24; 63.64).   3. High-voltage overmolded electrical transformer conforming to one of the resells 1 or 2, characterized in that the connection model (20) includes cut-off elements of the electrical supply adapted to cooperate with additional covering elements (35) integral with the cover (30).   4. High-voltage overmolded electrical transformer according to claim 3, characterized in that the cover (30) comprises a magnet (35) adapted to close a switch of the connection module (20) when the cover   (30) is arranged in contact with the connection module (20).   5. Overmolded high-voltage electrical transformer conforming to   one of claims 1 to 4, characterized in that the connection module   (20) further comprises an electronic protection device adapted to establish a cut in the power supply when a voltage is detected   differential, and possibly a no-load voltage.   6. Overmolded high-voltage electrical transformer conforming to   one of claims 1 to 5, characterized in that the cover (30) extends to the   above the connection terminals of the primary (14-17) and secondary (13, 18) and of the connection module (20, 60) circuits, the cover (30) comprising a free space (41) suitable for the passage of the cables of supply (C, 51) and output (13a, 18a) of the transformer, and in that the connection module (20,) is integral with a seal (40) adapted to close off said free space (41), the seal (40) comprising orifices for passage (42-45) of the supply cables (C,   51) and outlet (13a, 18a) of the transformer.   7. High-voltage overmolded electrical transformer according to claim 6, characterized in that the seal (40) has a slot (42a a) opening on the one hand into a passage orifice (42-45), and, on the other hand, in a free edge (40a) of the joint (40), the slot (42a-45a) being adapted for the passage of a supply or output cable (13a, 18a) of the transformer, and in that said slot (42a-45a) is adapted to be kept closed on the free edge (40a) of the seal (40) by a wing (36) of the cover (30) extending along said free edge (40a).