LED DRIVERS WITH CIRCUIT BOARD FUSE

Description

[0001] The present application relates generally to lighting technology, and in particular to a driver for LED lamps (LED driver) protected by a conductor track fuse.

[0002] DE 10 2016 114 985 A1 describes a light emission control device comprising a metal housing and a circuit board with terminal blocks. A protective cover is attached to an upper side of the circuit board. The protective cover is made of a synthetic resin with electrical insulation properties. The protective cover protects circuit components mounted on the circuit board, with the exception of the terminal blocks.

[0003] Fuses serve as mains-side overcurrent protection for LED drivers. Blowing such fuses can release hot gases and / or debris. In this regard, there is a regulatory requirement to prevent such hot gases and / or debris from escaping from the LED driver enclosure in which the fuse is located (see IEC 61347).

[0004] LED drivers operating under DC power are particularly risky, as the fuse is often located near the DC connection and thus close to a DC connection opening in the housing. This obviously increases the risk of hot gases and / or debris escaping from this opening. Any spark or arc that may occur upon triggering can persist for a longer period due to the lack of a zero crossing of the DC voltage. Special fuses designed for DC operation are expensive and have a large form factor.

[0005] However, hot gases spreading within the enclosure can be problematic in themselves if they are released to the connection surfaces of the power supply. These connection surfaces are designed according to standards, i.e., with safety and creepage distances that do not take hot gases into account, and can be short-circuited in the presence of hot gases.

[0006] Consequently, it is necessary to improve the operational reliability of LED drivers during DC operation.

[0007] According to the invention, this object is achieved by independent claim 1. Preferred embodiments are defined in the dependent claims as well as in the description and the drawings.

[0008] One aspect of the present application relates to an LED driver. The LED driver comprises an electrically conductive housing, a main board, and at least one foil between the housing and the main board. The main board comprises circuit components for regulating electrical power transmitted between a mains connection and a DC connection of the LED driver, and a circuit trace fuse for protecting the LED driver from electrical overload. The at least one foil is configured to substantially fill an air gap between itself and the main board and shield the mains connection from emissions resulting from the fuse blowing.

[0009] The at least one film may comprise a film having a main portion lining the housing, an adjoining cover fold portion, and an adjoining standing seam portion.

[0010] The cover fold section can be folded into the casing via a cover fold line.

[0011] The standing fold section can be folded over a standing fold line protruding from the cover fold section.

[0012] The cover fold section, the standing seam section and the main board may be substantially identical in size in one direction of the fold lines.

[0013] The envelope fold section may be dimensioned in a direction perpendicular to the envelope fold line such that the envelope fold section folded into the housing terminates between the mains connection and the fuse.

[0014] The standing seam portion may be dimensioned in a direction perpendicular to the standing seam line such that the standing seam portion folded away from the cover fold portion substantially fills the air gap between the film and the main board.

[0015] The at least one film may comprise a film lining the housing and another film having a main section and a standing seam section.

[0016] The standing seam section of the further film can be folded over a standing seam line protruding from the further film.

[0017] The further foil can be arranged between the one foil and the main board in such a way that the standing fold line of the further foil is arranged between the power connection and the fuse and is aligned substantially parallel to the standing fold line of the foil.

[0018] The main section of the further film, the standing seam section of the further film and the main board can be substantially identical in size in a direction of the standing seam line of the further film.

[0019] The standing seam section of the further film can be dimensioned in a direction perpendicular to its standing seam line such that the standing seam section folded away from the further film substantially fills the air gap between the one film and the main board.

[0020] Further features, advantages and characteristics of the present invention will now be explained by means of embodiments with reference to the figures of the accompanying drawings. Fig. 1 shows schematically an LED driver according to the invention; Fig. 2 to 5 show the film according to an embodiment of the LED driver according to the invention; Figs. 6 and 7 show a familiar slide; Figs. 8 and 9 show a further film according to an embodiment of the LED driver according to the invention. Figs. 10 and 11 show a further film according to a further embodiment of the LED driver according to the invention.

[0021] The disclosure will now be explained in more detail with reference to the various embodiments. Unless otherwise stated, features of different embodiments can be combined with one another.

[0022] Fig. 1 shows schematically an LED driver 1 according to the invention.

[0023] The LED driver 1 comprises an electrically conductive housing 101, made in particular of metal, a main board 102 and at least one film 105, 105', 105" between the housing 101 and the main board 102.

[0024] The main board 102 has circuit components for regulating an electrical power transmitted between a mains terminal 103 and a DC terminal of the LED driver 1, and a circuit fuse 104 for protecting the LED driver 1 from electrical overload.

[0025] Fuse 104 is in Fig. 1Only shown as a component fuse for the sake of clarity, but is actually designed as a circuit board fuse.

[0026] In a first embodiment (cf. Fig. 1 - 5 ) the at least one film 105, 105', 105" comprises a film 105 with a main section 106 lining the housing 101, an adjoining cover fold section 107 and an adjoining standing fold section 108.

[0027] The main section 105 serves for potential separation between the electrically conductive housing 101 of the LED driver 1 and the main board 102 of the LED driver 1. An elongated hole in the main section 105 provides a defined ground connection between the main board 102 and the housing 101, ie it is a recess that encompasses a housing-side support for the main board 102.

[0028] One foil 105 has, according to Fig. 2four fold lines, which run parallel to each other in the direction of a longer dimension of the film 105 and serve to cut out the flat one film 105 of the Fig. 2 the shaft-like folded foil 105 of the Fig. 3 which can line the slightly larger housing 101 of the LED driver 1 and even accommodate the main board 102 of the LED driver 1.

[0029] The one foil 105 of the LED driver 1 according to the invention from Fig. 1 includes, in comparison to a known, in Fig. 6 - 7 shown a slide 105 an extension. The Fig. 1 - 5 It can be seen that a fold-over section 107 adjoins the main section 106 lining the housing 101.

[0030] A "fold" can refer in particular to a sharp crease (fold line) in a sheet material whose thickness is at least one order of magnitude smaller than its lateral dimensions.

[0031] A "fold over fold" can refer in particular to a fold in which the sheet material forms an angle of substantially 0° at the sharp crease edge (fold over fold line), so that sections of the sheet material lie on top of one another.

[0032] A "cover fold section" may refer in particular to a section of the sheet material adjoining a cover fold line.

[0033] The cover fold section 107 can be formed via a cover fold line 109 (cf. Fig. 3 - 5 ) into the housing 101. Fig. 1 and 5 show the cover fold section 107 already folded into the housing 101.

[0034] According to Fig. 1 - 5 A standing seam section 108 is also attached to the cover fold section 107.

[0035] A "standing seam" can in particular refer to a fold whose flat material at the sharp crease edge (standing seam line) encloses an angle of between 45° and 135°, preferably between 60° and 120°, more preferably between 75° and 105°, and most preferably an angle of substantially 90°.

[0036] A "standing seam section" may in particular refer to a section of the sheet material adjacent to a standing seam line.

[0037] The standing seam section 108 can be connected via a standing seam line 110 (cf. Fig. 3 - 5 ) be foldable protruding from the cover fold section 107. Fig. 1 and 5 show the standing seam section 108 already folded from the cover fold section 107.

[0038] The cover fold section 107, the standing seam section 108 and the main board 102 can be dimensioned substantially identically in a direction of the fold lines 109, 110.

[0039] A "dimension" may in particular refer to a length dimension of a physical object in a specified spatial direction.

[0040] The cover fold section 107 can be dimensioned in a direction perpendicular to the cover fold line 109 such that the cover fold section 107 folded into the housing 101 terminates between the power connection 103 and the fuse 104.

[0041] The standing seam section 108 can be dimensioned in a direction perpendicular to the standing seam line 110 such that the standing seam section 108, folded away from the cover fold section 107, essentially fills the air gap between the one film 105 and the main board 102. Complete sealing is not required. This purpose is already fulfilled if the release of material upon triggering of the fuse 104 is reliably prevented.

[0042] Accordingly, one film 105 of the LED driver 1 according to the invention is designed such that it shields the mains connection 103, and in particular its connection surfaces on a main board side of the fuse 104, from emissions due to a triggering of the fuse 104.

[0043] This prevents the unfavorable scenario of hot gases being released to the connection surfaces of the power supply 103 as a result of the fuse 104 being triggered. The material of the connection surfaces is protected, thus achieving improved operational reliability of the LED driver 1 during DC operation.

[0044] In a second embodiment, the at least one film 105, 105', 105" comprises a film 105 lining the housing 101 (cf. Fig. 6 - 7 ) and another slide 105' (cf. Fig. 8 - 9 ).

[0045] The one film 105 lining the housing 101 can, for example, be a known film 105 as shown in the Figs. 6 and 7 This could be due to production-related reasons, for example, to avoid investing in new tools.

[0046] The additional foil 105' can comprise a main section 106' and a standing seam section 108'. It can simply be additionally applied to the foil 105 during the manufacture of the LED driver 1.

[0047] As already mentioned, an elongated hole in the main section 106' serves to provide a defined ground connection between the main board 102 and the housing 101.

[0048] Again Figs. 8 and 9 As can be seen, this embodiment can further comprise a cover fold section 107' connecting the main section 106' and the standing seam section 108'. The cover fold section 107' can be folded back onto the main section 106' via a cover fold line 109'. Figs. 8 and 9show the cover fold section 107' already folded back onto the main section 106'.

[0049] The standing seam section 108' of the further film 105' can be folded over a standing seam line 110' protruding from the further film 105'. Figs. 8 and 9 show the standing seam section 108 which has already been folded away from the further film 105', more precisely from the cover fold section 107'.

[0050] As in particular Fig. 9 As can be seen, the main section 106' of the further film 105', the standing seam section 108' of the further film 105', and the main plate 102 can be dimensioned essentially identically in a direction of the standing seam line 110' of the further film 105'. This dimensioning can also apply to the cover fold section 107' of the further film 105'.

[0051] The standing seam section 108' of the further film 105' can be dimensioned in a direction perpendicular to its standing seam line 110' such that the standing seam section 108' folded away from the further film 105' substantially fills the air gap between the one film 105 and the main board 102.

[0052] As in particular Fig. 9 As can be seen, the further film 105' can be arranged between the one film 105 and the main board 102 in such a way that the standing fold line 110' of the further film 105' is arranged between the mains connection 103 and the fuse 104 and is aligned substantially parallel to the standing fold line 110 of the one film 105.

[0053] Accordingly, the further film 105' of the LED driver 1 according to the invention is designed such that it shields the mains connection 103, and in particular its connection surfaces on the main board side of the fuse 104, from emissions resulting from the triggering of the fuse 104.

[0054] This also prevents the unfavorable scenario of hot gases being released as a result of the fuse 104 blowing, reaching the connection surfaces of the power supply 103. The material of the connection surfaces is protected, thus achieving improved operational reliability of the LED driver 1 during DC operation.

[0055] In conjunction with the one slide 105 of the Fig. 6 - 7 In addition to potential separation, shielding of hot gases can be achieved.

[0056] In a third embodiment, the at least one film 105, 105', 105" comprises the film 105 lining the housing 101 (cf. Fig. 6 - 7) and another slide 105" (cf. Fig. 10 - 11 ).

[0057] The further film 105" may comprise a main section 106" and a standing seam section 108".

[0058] A slotted hole in the main section 106" serves the previously disclosed purpose of providing a defined ground connection between the main board 102 and the housing 101.

[0059] Like the Fig. 10 - 11 As can be seen, in this embodiment, the standing seam section 108" can directly adjoin the main section 106", wherein the standing seam section 108" can comprise a folded extension. The standing seam section 108" of the further film 105" can be foldable via a standing fold line 110" protruding from the further film 105". Figs. 10 and 11 show the standing seam section 108" which is already folded from the further film 105", more precisely from its main section 106".

[0060] As in particular Fig. 11As can be seen, the main section 106" of the further film 105", the standing seam section 108" of the further film 105" and the main board 102 can be dimensioned essentially identically in a direction of the standing seam line 110" of the further film 105". This dimensioning can also apply to the folded extension of the standing seam section 108".

[0061] The standing seam section 108" of the further film 105" can be dimensioned in a direction perpendicular to its standing seam line 110" such that the standing seam section 108" folded away from the further film 105" substantially fills the air gap between the one film 105 and the main board 102.

[0062] As in particular Fig. 11As can be seen, the further film 105" can be arranged between the one film 105 and the main board 102 in such a way that the standing fold line 110" of the further film 105" is arranged between the power connection 103 and the fuse 104 and is aligned substantially parallel to the standing fold line 110 of the film 105.

[0063] Accordingly, the further film 105" of the LED driver 1 according to the invention is also designed such that it shields the mains connection 103, and in particular its connection surfaces on the main board side of the fuse 104, from emissions resulting from the triggering of the fuse 104.

[0064] This again prevents the unfavorable scenario of hot gases being released as a result of the fuse 104 blowing, reaching the connection surfaces of the power supply 103. The material of the connection surfaces is protected, thus achieving improved operational reliability of the LED driver 1 during DC operation.

[0065] In conjunction with the one slide 105 of the Fig. 6 - 7 In addition to potential separation, shielding of hot gases can be achieved.

[0066] In comparison to the other foil 105" the Figs. 8 and 9 less material is required and production / folding is easier.

Claims

1. LED driver (1) comprising an electrically conductive housing (101); a main board (102) having circuit components for controlling electrical power transmitted between a mains connection (103) and a DC connection of the LED driver (1); and a conductor track fuse (104) for protecting the LED driver (1) from electrical overload; and at least one film (105, 105', 105") between the housing (101) and the main board (102); the at least one film (105, 105', 105") being designed such that it substantially fills an air gap between itself and the main board (102), characterized in that the at least one film (105, 105', 105") is designed such that it shields the mains connection (103) from emissions resulting from triggering of the fuse (104).

2. LED driver (1) according to claim 1, wherein the at least one film (105, 105', 105") comprises a film (105) having a main portion (106) lining the housing (101), an adjoining folded-over portion (107) and an adjoining standing folded portion (108).

3. LED driver (1) according to claim 2, wherein the folded-over portion (107) can be folded into the housing (101) via a fold-over line (109).

4. LED driver (1) according to either claim 2 or claim 3, wherein the standing folded portion (108) can be folded via a standing fold line (110) so as to protrude from the folded-over portion (107).

5. LED driver (1) according to any of claims 2 to 4, wherein the folded-over portion (107), the standing folded portion (108) and the main board (102) have substantially identical dimensions in a direction of the fold lines (109, 110).

6. LED driver (1) according to any of claims 2 to 4, wherein the folded-over portion (107) is dimensioned in a direction perpendicular to the fold-over line (109) such that the folded-over portion (107) folded into the housing (101) terminates between the mains connection (103) and the fuse (104).

7. LED driver (1) according to any of claims 2 to 4, wherein the standing folded portion (108) is dimensioned in a direction perpendicular to the standing fold line (110) such that the standing folded portion (108) folded so as to protrude from the folded-over portion (107) substantially fills the air gap between the one film (105) and the main board (102).

8. LED driver (1) according to claim 1, wherein the at least one film (105, 105', 105") comprises a film (105) lining the housing (101) and a further film (105', 105") having a main portion (106') and a standing folded portion (108').

9. LED driver (1) according to claim 8, wherein the standing folded portion (108') of the further film (105', 105") can be folded via a standing fold line (110') so as to protrude from the further film (105', 105").

10. LED driver (1) according to claim 9, wherein the further film (105', 105") is arranged between the one film (105) and the main board (102) such that the standing fold line (110') of the further film (105', 105") is arranged between the mains connection (103) and the fuse (104) and is aligned substantially parallel to the standing fold line (110) of the one film (105).

11. LED driver (1) according to any of claims 8 to 10, wherein the main portion (106') of the further film (105', 105"), the standing folded portion (108') of the further film (105', 105") and the main board (102) have substantially identical dimensions in a direction of the standing fold line (110') of the further film (105', 105").

12. LED driver (1) according to any of claims 8 to 11, wherein the standing folded portion (108') of the further film (105', 105") is dimensioned in a direction perpendicular to the standing fold line (108') thereof such that the standing folded portion (108') folded so as to protrude from the further film (105', 105") substantially fills the air gap between the one film (105) and the main board (102).