GB2039692A

GB2039692A - High-voltage connection arrangements

Info

Publication number: GB2039692A
Application number: GB7942540A
Authority: GB
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1978-12-13
Filing date: 1979-12-10
Publication date: 1980-08-13
Also published as: ES247411U; JPS5583467A; BR7908109A; DE2853879B2; DE2853879C3; ES247411Y; DE2853879A1

Abstract

In a connection arrangement for a high voltage cable 4 which carries the high-voltage output of a voltage multiplier cascade within casing 6, a screw has its head 2 welded to a connector 7 and has its screw-threaded shank 1 extending into a tube 3 of electrically insulating material. The cable 4 is inserted into tube 3 and screwed onto shank 1 after assembly and potting of the cascade. <IMAGE>

Description

SPECIFICATION High-voltage connection arrangements The present invention relates to high-voltage connection arrangements and is applicable to voltage multiplier cascades e.g. for television sets. A cascade consists of a casing which contains potted capacitors, one of which is connected to a high-voltage cable. This high-voltage cable is held inside the potting compound and should be connected to the capacitors in such a way that creepage currents or flash-overs of high-voltage to other connectors or contact points are safely avoided.

Such a voltage multiplier cascade is known from German Patent Specification No. 25 33 720. There the high-voltage connector is potted with the components of the cascade. After completion of the cascade, modification of the HV-cable according to the needs of the customer is no longer possibie. The most that can be done is to shorten the cable, It is no longer possible, for instance, to insert a resistance cable.

An object of the invention is to provide an improved connection arrangement for high-voltage cables.

According to one aspect of the invention, there is provided a connection arrangement for a highvoltage cable and comprising: a screw having a head and a screw-threaded shank; and an elongate tube of electrically insulating material surrounding the shank, whereby a high-voltage cable may be inserted through said tube and screwed onto said shank.

Preferably, the head is fixed within a casing, and said tube projects from the casing.

Expediently, the shank is conical.

Electrical components, e.g. at least one capacitor, may be contained in said casing and electrically connected to said head.

According to a further aspect of the invention there is provided a voltage multiplier cascade including a connection arrangement according to said one aspect, the capacitors being potted within said casing.

Preferably, a protective resistor is potted within said casing.

Preferably, one terminal of said resistor is welded to said head.

The cable, when provided, may serve as a load resistance or bleeder for the cascade.

According to a further aspect of the invention, there is provided a method for manufacturing said voltage multiplier cascade in which the screw is fixed within the casing before potting thereof and the shank is separated from the inside of the casing by the insulated tube in a fluid-tight manner; the cascade is the potted; and the cable is screwed in after hardening of the potting compound.

According to a further aspect of the invention, there is provided a method of making an electrical connection to a high-voltage cable in which the cable is inserted through a tube of electrically insulating material and is screwed onto a screw whose screwthreaded shank projects into the tube.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the single Figure of the accompanying drawing, which shows a voltage multiplier cascade in a lateral particularly cut-away view.

A cup 6 contains potted capacitors and, if desired, a protective resistor. A high-voltage cable 4 is inserted into the cascade through an insulating tube 3 fixed to a contact screw 1. The contact screw 1 spreads out the HV-cable 4 so that the cable insulation is expanded with a force against the inner wall of the insulated tube 3. The tube 3 is closed in a fluid-tight manner by screw 1. The head 2 of the contact screw 1 is welded to a connector 7 of the protective resistor or of one of the capacitors.

The insulated tube 3 extends from the cup 6 and is also potted. Because of this seal and because of the seal between the tube 3 and the uninsulated part of the contact screw 1 by means of the expanded HV-cable, not only leakage or creepage currents but also flash-overs between connector 7 and other conducting parts of the cascade, e.g. the outer connector 5, will not normally occur.

The described and illustrated arrangement has the advantage that during assembly and potting, no suspended cable from the cascade interferes with subsequent stages of manufacture, and that any kind of HV-cable can be fixed after completion of the cascade, as there is no danger of voltage flash-overs or creepage currents.

Also, a preventive resistor can be sealed into the cup 6 and the contact screw 1 be welded to the free connector of the preventive resistor. A resistance cable is especially suitable for use as the highvoltage cable, which in turn, is suitable as a load resistance for the cascade circuit (bleeder).

The contact screw 1 is fixed before sealing and separated in a fluid-tight manner from the sealing chamber by the insulated tube. The cascade is then potted and the HV-cable, after hardening of the potting compound, is screwed in, the shank of the screw engaging firmly with the cable insulator. As a result the contact screw 1 contacts the cable conductor 4, and at the same time, the cable is wedged into the tube by expansion of the cable insulator. To this end the contact screw should preferably be designed in the shape of a cone. Cables of various thicknesses can be held in place mechanically by screwing cables of various thicknesses on to the contact screw, spacing them out at various distance, In each case the wedging in of the HV-cable will safely separate the uninsulated part of the contact screw from the disengaged part of the insulated tube. This ensures good insulation even in moist conditions.

1. Aconnection arrangement for a high-voltage cable and comprising: a screw having a head and a screw-threaded shank; and an elongate tube of electrically insulating material surrounding the shank, whereby a high-voltage cable may be inserted through said tube and screwed onto said shank.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION High-voltage connection arrangements The present invention relates to high-voltage connection arrangements and is applicable to voltage multiplier cascades e.g. for television sets. A cascade consists of a casing which contains potted capacitors, one of which is connected to a high-voltage cable. This high-voltage cable is held inside the potting compound and should be connected to the capacitors in such a way that creepage currents or flash-overs of high-voltage to other connectors or contact points are safely avoided. Such a voltage multiplier cascade is known from German Patent Specification No. 25 33 720. There the high-voltage connector is potted with the components of the cascade. After completion of the cascade, modification of the HV-cable according to the needs of the customer is no longer possibie. The most that can be done is to shorten the cable, It is no longer possible, for instance, to insert a resistance cable. An object of the invention is to provide an improved connection arrangement for high-voltage cables. According to one aspect of the invention, there is provided a connection arrangement for a highvoltage cable and comprising: a screw having a head and a screw-threaded shank; and an elongate tube of electrically insulating material surrounding the shank, whereby a high-voltage cable may be inserted through said tube and screwed onto said shank. Preferably, the head is fixed within a casing, and said tube projects from the casing. Expediently, the shank is conical. Electrical components, e.g. at least one capacitor, may be contained in said casing and electrically connected to said head. According to a further aspect of the invention there is provided a voltage multiplier cascade including a connection arrangement according to said one aspect, the capacitors being potted within said casing. Preferably, a protective resistor is potted within said casing. Preferably, one terminal of said resistor is welded to said head. The cable, when provided, may serve as a load resistance or bleeder for the cascade. According to a further aspect of the invention, there is provided a method for manufacturing said voltage multiplier cascade in which the screw is fixed within the casing before potting thereof and the shank is separated from the inside of the casing by the insulated tube in a fluid-tight manner; the cascade is the potted; and the cable is screwed in after hardening of the potting compound. According to a further aspect of the invention, there is provided a method of making an electrical connection to a high-voltage cable in which the cable is inserted through a tube of electrically insulating material and is screwed onto a screw whose screwthreaded shank projects into the tube. For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the single Figure of the accompanying drawing, which shows a voltage multiplier cascade in a lateral particularly cut-away view. A cup 6 contains potted capacitors and, if desired, a protective resistor. A high-voltage cable 4 is inserted into the cascade through an insulating tube 3 fixed to a contact screw 1. The contact screw 1 spreads out the HV-cable 4 so that the cable insulation is expanded with a force against the inner wall of the insulated tube 3. The tube 3 is closed in a fluid-tight manner by screw 1. The head 2 of the contact screw 1 is welded to a connector 7 of the protective resistor or of one of the capacitors. The insulated tube 3 extends from the cup 6 and is also potted. Because of this seal and because of the seal between the tube 3 and the uninsulated part of the contact screw 1 by means of the expanded HV-cable, not only leakage or creepage currents but also flash-overs between connector 7 and other conducting parts of the cascade, e.g. the outer connector 5, will not normally occur. The described and illustrated arrangement has the advantage that during assembly and potting, no suspended cable from the cascade interferes with subsequent stages of manufacture, and that any kind of HV-cable can be fixed after completion of the cascade, as there is no danger of voltage flash-overs or creepage currents. Also, a preventive resistor can be sealed into the cup 6 and the contact screw 1 be welded to the free connector of the preventive resistor. A resistance cable is especially suitable for use as the highvoltage cable, which in turn, is suitable as a load resistance for the cascade circuit (bleeder). The contact screw 1 is fixed before sealing and separated in a fluid-tight manner from the sealing chamber by the insulated tube. The cascade is then potted and the HV-cable, after hardening of the potting compound, is screwed in, the shank of the screw engaging firmly with the cable insulator. As a result the contact screw 1 contacts the cable conductor 4, and at the same time, the cable is wedged into the tube by expansion of the cable insulator. To this end the contact screw should preferably be designed in the shape of a cone. Cables of various thicknesses can be held in place mechanically by screwing cables of various thicknesses on to the contact screw, spacing them out at various distance, In each case the wedging in of the HV-cable will safely separate the uninsulated part of the contact screw from the disengaged part of the insulated tube.This ensures good insulation even in moist conditions. CLAIMS

2. An arrangement according to claim 1 wherein a high-voltage cable is screwed onto said shank, the conductor of the cable making electrical contact with the shrank.

3. An arrangement according to claim 1 or 2 wherein the head is fixed within a casing, and said tube projects from the casing.

4. A connection arrangement according to any one of the claims 1 to 3 wherein said shank is conical.

5. An arrangement according to any one of claims 1 to 4 wherein electrical components are contained in said casing and electrically connected to said head.

6. An arrangement according to claim 5 wherein the casing contains at least one capacitor.

7. A connection arrangement substantially as hereinbefore described with reference to the accompanying drawing.

8. A voltage multiplier cascade including a connection arrangement according to claim 6 or 7, the capacitors being potted within said casing.

9. A cascade according to claim 8 wherein a protective resistor is provided potted within said casing.

10. A cascade according to claim 9 wherein one terminal of said resistor is welded to said head.

11. A cascade according to any one of claims 8 to 10 including a connection arrangement according to claim 2 wherein the cable serves as a load resistance or bleeder for the cascade.

12. Avoltage multiplier cascade, in particularfor television sets, containing capacitors which are sealed into a cup, one of the capacitors being connected to a HV-cable and this HV-cable being held inside the sealing compound and wired to the capacitor connector in such a way that creepage currents or flash-overs of high-voltage to other connectors or contact points are prevented wherein said one capacitor being connected to a contact screw, which resembles a wood screw and is fixed near the bottom of the cup with its thread rising almost vertically from the bottom of the cup; wherein an electricaly insulated tube separates the contact screw from the sealing chamber; and wherein the tube projects out of the sealing compound and the high-voltage cable is housed in the insulated tube and screwed on to the contact screw.

13. A voltage multiplier cascade substantially as hereinbefore described with reference to the accompanying drawing.

14. Atelevision set including a voltage multiplier cascade according to any one of claims 8 to 13.

15. A method for manufacturing a voltage multiplier cascade in accordance with any one of claims 8 to 13 in which: the screw is fixed within the casing before potting thereof and the shank is separated from the inside of the casing by the insulated tube in a fluid-tight manner; the cascade is then potted; and the cable is screwed in after hardening of the potting compound.

16. A method for manufacturing a voltage multiplier cascade according to claim 15 and substantially as hereinbefore described.

17. A method of making an electrical connection to a high voltage cable in which the cable is inserted through a tube of electrically insulating material and is screwed onto a screw whose screw-threaded shank projects into the tube.