POWER SUPPLY UNIT

Abstract

Power supply unit, in particular for a sterilization device, comprising at least one electric component, wherein, at least one of the electric components is at least partly covered with a solid insulation layer, wherein the solid insulation layer is adapted to provide an electric insulation.

Claims

1. Power supply unit for a sterilization device, comprising: a housing; at least one electric component disposed within the housing and configured to provide an output voltage to a high voltage output connector, at least one of the electric components is at least partly covered with a solid insulation layer that provides electric insulation to the at least one of the electric component.

2. Power supply unit according to claim 1, wherein the at least one electric component comprises at least a first element configured to operate at a first voltage and a second element configured to operate at a second voltage, said second voltage being lower than the first voltage, a zone of the at least one electric component that encompasses the at least first element being covered with the solid insulation layer.

3. Power supply unit according to claim 1, wherein the solid insulation layer provides a dielectric strength, and a value of the dielectric strength being selected in dependence of the first voltage.

4. Power supply unit according to claim 1, wherein the solid insulation layer comprises epoxy.

5. Power supply unit according to claim 1, wherein the housing comprises at least one electric insulation shield.

6. Power supply unit according to claim 1, wherein the solid insulation layer is provided by potting.

7. Power supply unit according to claim 1, wherein the solid insulation layer comprises a current conductive additive.

8. Power supply unit according to claim 1, wherein the solid insulation layer comprises a heat conductive additive.

9. Power supply unit according to claim 1, wherein the solid insulation layer is connected to a heat absorber unit.

10. Power supply unit according to claim 1, wherein the at least one electric component is a voltage multiplier (26), and wherein the voltage multiplier comprises two circuit boards.

11. Power supply unit according to claim 1, wherein the solid insulation layer comprises an inner surface and an outer surface, the outer surface possessing a radius bigger than about 3 mm.

12. Sterilization device for packaging material, comprising a power supply unit and at least one electron beam emitter, the power supply unit comprising at least one electric component, wherein at least one of the electric components is at least partly covered with a solid insulation layer.

13. Electric component (22), in particular that is a voltage multiplier, the electric component comprising at least one voltage distribution during operation, a zone of the electric component whose voltage distribution during operation exceeds a first voltage threshold being covered with a solid insulation layer that electrically insulates the zone.

14. Power supply unit according to claim 1, wherein the solid insulation layer is connected to a heat sink.

15. Power supply unit according to claim 1, wherein at least a part of the one electric component is exposed outside the solid insulation layer.

16. Power supply unit according to claim 1, wherein the at least one electric component comprises a first element which operates at a first voltage and a second element which operates at a second voltage, the second voltage being lower than the first voltage, the first element being covered by the solid insulation layer, the second element being exposed outside the solid insulation layer.

17. Sterilization device according to claim 12, wherein at least a part of the one electric component is exposed outside the solid insulation layer.

18. Sterilization device according to claim 12, wherein the at least one electric component comprises a first element which operates at a first voltage and a second element which operates at a second voltage, the second voltage being lower than the first voltage, the first element being covered by the solid insulation layer, the second element being exposed outside the solid insulation layer.

Description

[0041] FIG. 1a: shows an electric component without an insulation layer;

[0042] FIG. 1b: shows according to one or more embodiments an electric component that is electrically insulated by potting;

[0043] FIG. 1c: shows according to one or more embodiments an electric component that is electrically insulated by conformal coating;

[0044] FIG. 2: shows according to one or more embodiments a power supply unit comprising an electric system;

[0045] FIG. 3: shows a further embodiment of a power supply unit;

[0046] FIG. 4a: shows an embodiment of a voltage multiplier;

[0047] FIG. 4b: shows the embodiment of FIG. 4a in a view along an axis A;

[0048] FIG. 5: shows an embodiment of an electron beam emitter;

[0049] FIG. 6: shows a further embodiment of an electron beam emitter.

[0050] Referring now to FIG. 1a an electric component 22 is shown. The electric component 22 comprises a plurality of electric elements 24.

[0051] FIG. 1b shows an insulation layer 46 arranged partly over electric component 22. Electric elements 24, which operate, create or handle potential or voltages exceeding at least a first voltage threshold are covered by solid insulation layer 40. The solid insulation layer 40 is provided by potting. The solid insulation layer 40 comprises an outer surface 44, which substantially flat and an inner surface. The inner surface of solid insulation layer 40 is at least partly in contact with the electric component 22. The upper area of the electric component 22 is not covered by insulation layer 46, as the components arranged in that area do not operate, create, use or handle voltages exceeding the first voltage threshold. In this case, an additional solid insulation layer is not necessary.

[0052] FIG. 1c illustrates the electric component 22 that is already known from FIGS. 1a and 1 b. A zone 46 that exceeds a first voltage threshold is covered by a solid insulation layer 40, wherein the solid insulation layer 40 is provided by conformal coating. As a result the coating follows the shape of the electrical elements 24 arranged on the board.

[0053] FIG. 2 shows a power supply unit 10 according to an embodiment. The power supply unit 10 comprises a housing 13, wherein the housing 13 is separated into a first chamber 11 and a second chamber 12. Both chambers 11, 12 comprise fans 15 that are adapted to cool the electric system 20 arranged inside the housing. Expediently, the chambers 11, 12 are filled with an insulation medium 70, in particular an insulation gas, such as nitrogen. The insulation medium 70 is also used for cooling of the electric system 20, e. g. using the fans 15. The solid insulation layers 40 of the electric system 20 are cooled by medium 70.

[0054] However, the electric system 20 comprises usually control system components, power components and high voltage components, wherein the control system components and control components are expediently arranged in the second chamber 12 and wherein the high voltage components, as for example a voltage multiplier 22, is arranged expediently in the first chamber 11. The voltage multiplier 22 is connected to a high voltage output connector 14 that is adapted for a connection to an electron beam emitter (not shown). The voltage multiplier 22 as shown in FIG. 2 comprises a first circuit board 26. A zone 46 of the voltage multiplier 22 that exceeds at least a first voltage threshold is covered with a solid insulation layer 40. Expediently, also a spark current limiter 28 is covered with an insulation layer (not shown). According to one or more embodiments the threshold lies within a range of about 80 to 90 kV. An output voltage of the voltage multiplier 20 lies according to one or more embodiments in the range of about 110 to 120 kV (also up to 150 kV).

[0055] FIG. 3 shows a further embodiment of a power supply unit 10. This embodiment is similar to the one shown in FIG. 2. However, a voltage multiplier 22 comprises a first circuit board 26 and a second circuit board 26. The two circuit boards 26 and 26 are connected via an interconnection board 29. Between the interconnection board 29 and the second circuit board 26 a spark current limiter 28 is arranged. Each of the circuit boards 26, 26 comprises advantageously at least one multiplier stage. According to one or more embodiments the first circuit board 26 comprises five stages, wherein the second circuit board 26 comprises two stages.

[0056] Each stage comprises appropriate diodes and capacitors to enable the voltage multiplication (not shown). The first circuit board 26 is adapted to multiply an input voltage up to 80 to 90 kV. The second circuit board 26 is adapted to multiply the output voltage of the first circuit board up to 110 or 120 kV (also up to 150 kV). FIG. 3 shows that the second circuit board 26 and the spark current limiter 28 are additionally electrically insulated by an insulation shield 48. The insulation shield 48 is arranged and/or attached at and/or in the wall(s) of the housing 13. According to one or more embodiments, the insulation shield 48 is made of polyethylene. The insulation shield 48 has the advantage that an electric field in the area of the second circuit board 26 can be lowered. This enables the use of epoxy for the material for the solid insulation layer. The remaining features are similar to these shown and explained in FIG. 2.

[0057] FIG. 4a shows an embodiment of a voltage multiplier used in a power supply unit as illustrated in FIG. 3. As can be seen from FIG. 4a, the interconnection board 29, the spark current limiter 28 and the second circuit board 26 are electrically insulated by a solid insulation layer 40. Potting can be used to create the solid insulation layer 40. Alternatively or at least partly also conformal coating may be used. According to one or more embodiments the material that is used for the solid insulation layer 40 is epoxy.

[0058] FIG. 4b shows the embodiment of FIG. 4a in a view along the axis A. To be exact, a sectioning is shown so that the spark current limiter 28 and the lower part of the voltage multiplier 26 (in particular the second circuit board 26) can be seen from above. Thus, a position of the spark current limiter 28 relating to the voltage multiplier 26 can be seen. The voltage multiplier 26 comprises a hole that is adapted to arrange the high voltage output connector 14 (not shown in FIG. 4b). The spark current limiter 28 and the voltage multiplier are covered with the solid insulation layer 40.

[0059] FIG. 5 shows a principle scheme of an embodiment of a sterilization device comprising a power supply unit 10 and an electron beam emitter 60. The electron beam emitter 60 comprises an electron exit window 64, wherein an electron cloud 62 is formed during sterilization. The electron cloud 62 is for example used for inside sterilization of a packaging material 80, in particular a packaging container 80 (e. g a carton packaging container) as can be seen on the right.

[0060] FIG. 6 shows another embodiment of an electron beam emitter 60 comprising an electron exit window 64. The electron beam emitter 60 as shown in FIG. 6 is for example used for outside sterilization of packaging material, in particular packaging containers, or for sterilization of flat and/or plane materials or devices.

REFERENCE NUMERALS

[0061] 10 power supply unit [0062] 11 first chamber [0063] 12 second chamber [0064] 13 housing [0065] 14 high voltage output connector [0066] 15 fan [0067] 20 electric system [0068] 22 electric component [0069] 24 electric elements [0070] 26 voltage multiplier [0071] 26 first circuit board [0072] 26 second circuit board [0073] 28 spark current limiter [0074] 29 interconnection board [0075] 40 solid insulation layer [0076] 44 outer surface [0077] 46 zone that exceeds a first voltage threshold [0078] 48 insulation shield [0079] 60 electron beam emitter [0080] 62 electron cloud [0081] 64 electron exit window [0082] 70 insulation medium [0083] 80 packaging material