Abstract
A signaling device adapted to be electrically coupled to an electric potential applied to terminals of a fuse element or to clips of a fuse holder. The signaling device is adapted to signal to the outside at least one property of the fuse element. In addition, the signaling device includes at least one transmission layer having an electrically controllable transmission factor.
Claims
1. A signaling device configured to be electrically coupled to an electric potential applied to terminals of a fuse element or to clips of a fuse holder, wherein said signaling device is configured to signal to outside of the signaling device at least one property of said fuse element, and wherein said signaling device comprises at least one transmission layer having an electrically controllable transmission factor.
2. The signaling device according to claim 1, further comprising leads configured to connect the transmission layer and the fuse element in parallel.
3. The signaling device according to claim 2, wherein the leads comprise conductive rubber leads configured to provide an electrical connection between terminals of the transmission layer and the terminals of the fuse element or between terminals of the transmission layer and the clips of the fuse holder, respectively.
4. The signaling device according to claim 1, wherein the transmission layer is configured to control its transmission factor in relation to an electric potential applied to terminals of the transmission layer.
5. The signaling device according to claim 1, wherein the transmission layer comprises liquid crystals configured to be aligned in an electrical field.
6. The signaling device according to claim 1, wherein the transmission layer comprises a Polymere Dispersed Liquid Crystal, PDLC, layer.
7. The signaling device according to claim 1, further comprising a signaling layer arranged behind the transmission layer if viewed from the outside.
8. The signaling device according to claim 7, wherein the signaling layer comprises an information element configured to signal to the outside the at least one property of the fuse element.
9. The signaling device according to claim 8, wherein said information element is labeled and/or printed onto a surface of the signaling layer facing the transmission layer.
10. The signaling device according to claim 8, wherein said information element comprises at least one of color(s), sign(s), letter(s), wording(s), and number(s).
11. The signaling device according to claim 1, wherein the property of the fuse element comprises at least one of a conductive state or blocking state of said fuse element, a voltage, a current, and a temperature.
12. The signaling device according to claim 1, wherein the transmission factor of the transmission layer is controlled in a range between opaque and transparent.
13. The signaling device according to claim 12, wherein the signaling device is configured to control the transmission factor of the transmission layer to be transparent with the fuse element is in a blocking state, or to be opaque with the fuse element is in a conductive state.
14. An electrical fuse apparatus comprising a fuse element, a base for supporting the fuse element, and a signaling device according to claim 1, wherein said signaling device is electrically coupled to an electric potential applied to the fuse element.
15. A device comprising at least one electrical component and an electrical fuse apparatus according to claim 14, wherein said electrical fuse apparatus is configured to protect the electrical component against over-current.
16. A power entry module (PEM) adapted to supply an electrical appliance with power, said power entry module (PEM) comprising the electrical fuse apparatus according to claim 14.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention is further described with reference to the accompanying drawings jointly illustrating various exemplary embodiments which are to be considered in connection with the following detailed description. What is shown in the figures is:
[0022] FIG. 1 an embodiment of an electrical fuse apparatus with signaling device in a semi-transparent view;
[0023] FIGS. 2a,b schematically depict a signaling device in a side view and a top view, respectively;
[0024] FIGS. 3a-e schematically depict exemplary signaling device circuits;
[0025] FIGS. 4a,b different views of an electrical fuse apparatus having a cylindrical body in an embodiment;
[0026] FIG. 5 depicts a further embodiment of an electrical fuse apparatus in a perspective view;
[0027] FIGS. 6a-c show a cap in different views;
[0028] FIG. 7 shows an electrical fuse apparatus in a further embodiment; and
[0029] FIGS. 8a,b show exemplary electrical fuse apparatuses integrated in an appliance inlet or power entry module in a front view, respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIG. 1 shows an electrical fuse apparatus 10 in a semi-transparent view. The electrical fuse apparatus 10 comprises a replaceable fuse element 12, which can be supported by a fuse holder (not shown) comprising e.g. two fuse clips, each made of an electric conductive material. In the shown embodiment, the fuse element 12 is a cartridge fuse 12. The fuse clips can be adapted to, while supporting the cartridge fuse 12, provide an electrical connection between terminals 16a,b of the cartridge fuse 12 and solder pins (not shown), which can be comprised by the fuse clips, which solder pins can be electrically connected to e.g. conductive paths or pads comprised by a printed circuit board PCB (not shown) by means of e.g. soldering.
[0031] The electrical fuse apparatus 10 further comprises a signaling device 24 which, in the shown example, is disposed above the cartridge fuse 12 once inserted into the electrical fuse apparatus 10. The signaling device 24 can comprise terminals electrically connected to the terminals 16a,b of the cartridge fuse 12 or direct to the fuse clips by means of two conductive rubber leads 26a,b.
[0032] An exemplary signaling device 24 is schematically depicted in FIGS. 2a and 2b in a side view and a top view, respectively. A substrate 28 is configured for supporting components of the signaling device 24. The substrate 28 can be comprised of a printed circuit board PCB, conductive polymere, glass or ceramic substrate. The substrate 28 can be equipped with electrical components 29, e.g. SMD-components. The signaling device 24 comprises a top glass 30 to be further described in the following. The signaling device 24 further comprises a transmission layer 32 having an electrically controllable transmission factor. The transmission layer 32 can be controlled such to be opaque or transparent, wherein gradients or rather steps in the range between opaque and transparent are achievable. The substrate 28 can also support further electronic components of the signaling device 24, connected by means of e.g. electric paths comprised by the substrate 28.
[0033] In an example, the transmission layer 32 comprises liquid crystals adapted to be aligned in an electric field. In an example, the transmission layer 32 is a Polymere Dispersed Liquid Crystal, PDLC, layer, also referred as smart glass. Opposing ends of the substrate 28, as viewed in longitudinal extension thereof, are provided with electrical terminals, which are connected to the terminals 16a,b of the cartridge fuse (refer to FIG. 1) by means of the conductive rubber leads 26a,b. Due to its elasticity, the conductive rubber leads 26a,b provide reliable electrical connections between the terminals of the substrate 28 and the terminals 16a,b of the cartridge fuse or clips of the fuse holder, respectively. The electrical terminals of the substrate 28 are in turn electrically coupled to respective electrical terminals 33a,33b of the transmission layer 32. Said electrical terminals 33a,33b of the transmission layer 32 are connected to respective pads (not shown) arranged on the substrate 28 by means of e.g. conductive glue, solder bonding or diffusion bonding. Hence, in operation, the transmission layer 32 and the cartridge fuse are applied by essentially the same electric potential. Therefore, the transmission factor of the transmission layer 32 can be controlled in relation to the electric potential applied to the terminals 16a,b of the cartridge fuse.
[0034] Assumed that the cartridge fuse is in a conductive state or rather not blown, the electric field applied to the terminals 16a,b thereof is very low or rather negligible. The reason for this is that the electric resistance of the fuse wire can be neglected, resulting in an electric potential of almost zero. Therefore, the electrical potential applied to the transmission layer 32 is negligible, too, resulting in the transmission layer 32 is opaque. The transmission layer 32 remains opaque as long as the cartridge fuse is in its conductive state (not blown).
[0035] On the other hand, assumed that the cartridge fuse is blown, the electric potential applied to the terminals 16a,b of the cartridge fuse increases rapidly. Since the increased electric potential is also applied to the transmission layer 32, the transmission layer 32 becomes transparent or rather shifts from opaque to transparent. In other words, the transmission layer 32 becomes transparent immediately after the cartridge fuse is blown. This in turn results in a signaling layer 34 arranged beneath the transmission layer 32 becomes visible from the outside. Therefore, the operator is able to recognize that the cartridge fuse is blown, which allows him e.g. to identify the reason(s) thereof and afterwards substitute the blown cartridge fuse by a new cartridge fuse, if necessary.
[0036] The signaling layer 34 can comprise an information element 36 adapted to signal to the outside the at least one property of the cartridge fuse 12. The information element 36 can be labeled or printed onto the surface of the signaling layer 34, which is >=3 mm below the transmission layer 32. In the example shown in FIG. 2b, the information element 36 is a wording “DEFECT”. Next to a wording, the information element 36 can be colors, signs, letters, numbers, etc. Further, next to signaling to the outside a property of the cartridge fuse, i.e. blown or not blown, the signaling device 24 can signal further properties, e.g. a voltage, current, temperature, etc. The transmission layer 32 is covered from the above by means of the above-mentioned top glass 30, such to protect the transmission layer 32 against environmental influences, e.g. water, moisture, vandalism, etc. The top glass 30 is connected or rather adhered to the substrate 28 by means of a sealing layer 37 disposed beneath the top glass 30 in a periphery thereof. The opposing surfaces of the sealing layer 37 can comprise adhesive, such that the sealing layer 37 further acts as an adhesive layer. In doing so, e.g. an interior of the substrate 28 in a region beneath the transmission layer 32 is proper sealed against the environment.
[0037] FIGS. 3a-e schematically depict exemplary circuits of the signaling device 24.
[0038] FIG. 3a shows the signaling device 24 in a simplified schematic status indication for e.g. <=48V. The signaling device 24 can comprise the cartridge fuse 12 and the transmission layer 32 connected to each other in parallel. Of course, a fuse element different from the cartridge fuse 12 can be used, as shown in FIG. 7.
[0039] FIG. 3b shows the signaling device 24 in a simplified schematic status indication for e.g. up to 250 V. In this aspect, the signaling device 24 comprises the cartridge fuse 12, the transmission layer 32 and a capacity (capacitor) C. The transmission layer 32 and capacity C can be connected in series, while the series connection of the transmission layer 32 and capacity C can be connected to the cartridge fuse 12 in parallel. Of course, in both aspects, instead of the cartridge fuse as shown in FIG. 1, a fuse element different from said cartridge fuse can be used.
[0040] Further variants of the signaling device 24 are shown in FIGS. 3c-e, wherein FIG. 3c shows a schematic with highest safety requirement, FIG. 3d shows a standard schematic, and FIG. 3e shows a schematic of a low-cost version with reduced safety requirement. In the depicted variants, a suppressor diode D can be connected to the transmission layer 32 in parallel. Further, at least one capacitor C can be connected in series. In the variant achieving highest safety requirement, the signaling device 24 can be equipped with a fuse F (refer to FIG. 3c).
[0041] FIGS. 4a,b and 5 depict electrical fuse apparatuses 10 having essentially cylindrical bodies in different examples. FIGS. 4a,b show an electrical fuse apparatus 10 in an example in a side view and a perspective view, respectively. Said fuse apparatus 10 can be mounted in vertical orientation, allowing to safe mounting space on e.g. a PCB (not shown). The electrical fuse apparatus 10 can be equipped with a cartridge fuse (not shown) by simply removing a cap 38 fixed on the top, e.g. by means of unscrewing the cap 38, and then inserting the cartridge fuse from above. The thus equipped electrical fuse apparatus 10 can be closed again by screwing the cap 38.
[0042] FIG. 5 depicts an electrical fuse apparatus 10 having a cylindrical body in a further example in a perspective view. The shown electrical fuse apparatus 10 is adapted to be mounted in the housing of an electric appliance, e.g. a power supply unit. In the shown exemplary electrical fuse apparatuses 10, the top surfaces of the respective caps 38 are provided with the signaling device 24, which allows to signal to the outside the property of the inserted cartridge fuse.
[0043] FIGS. 6a-c show an exemplary cap 38 in different views, respectively. As shown, the outer periphery of the cap 38 can be knurled in order to allow screwing or unscrewing the cap 38 by hand. The top surface of the cap 38 is provided with the signaling device 24, which allows to signal to the outside the property of the inserted cartridge fuse. In a non-shown example, the top of the cap 38 can be provided with a slot allowing to be engaged by a tool, e.g. by a screwdriver (not shown), in order to allow screwing or unscrewing the cap solely by means of a tool.
[0044] The FIG. 7 shows an electrical fuse apparatus 100 in a further embodiment. The electrical fuse apparatus 100 comprises a fuse element 112 and a signaling device 124 formed integrally. The electrical fuse apparatus 100 can be supported by means of conductive terminals 114a,b, which can be coupled to conductive paths provided on a PCB, e.g. by means of soldering or might be coupled to conductive paths provided by a fuse clip. The signaling device 124 comprises a top glass 130 and a transmission layer 132 having an electrically controllable transmission factor. Conductive terminals of both the fuse element 112 and the signaling device 124 are connected to the terminals 114a,b in parallel by means of conductive leads 126a,b, e.g. vias, filled vias, holes, etc., respectively. Hence, essentially equal electric potentials are applied to both the fuse element 112 and signaling device 124, respectively. The electrical fuse apparatus 100 is further equipped with a signaling layer 134 which is visible to the outside once the transmission layer 132 is controlled to be transparent and is invisible from the outside once the transmission layer 132 is controlled to be opaque. This allows to signal to the outside the property of the fuse element 112. The transmission layer 132 can be disposed beneath the top glass 130 such to be protected against the environment.
[0045] FIGS. 8a,b show exemplary appliance inlets or rather power entry modules PEM in front views, respectively. The power entry modules PEM comprise connectors 201, each adapted to receive a corresponding connector of a power cord (not shown). Further comprised is an integrated electrical fuse apparatus 200 equipped with an integrated fuse holder for cartridge fuses (both not shown). The power entry modules PEM are for suppling a device (not shown) with power, e.g. AC power. The power entry module PEM shown in FIG. 8b is further provided with a power switch 250.
[0046] At least one phase of the power supply can be protected against e.g. over current by means of the integrated electrical fuse apparatus 200 (not shown). Further provided is a signaling device 224, which is configured to signal to the outside at least one property of the inserted fuse element. Said signaling device 224 comprises a top glass 230, wherein one surface thereof is exposed to the outside. Further comprised is a transmission layer 232 having a controllable transmission factor. The transmission layer 232 is arranged such to be protected against the environment by means of the top glass 230. The signaling of the at least one property of the inserted fuse element is achieved by controlling the transmission layer 232 to be transparent or to be opaque. The FIGS. 8a,b show the transmission layer 232 opaque, which signals to the outside that the fuse element is not blown. While not shown, in case of the transmission layer 232 is shifted to be transparent, this would signal to the outside that the cartridge fuse is blown. Therefore, the operator is able to easily recognize the respective property of the cartridge fuse, i.e. blown or not blown.
