ARRANGEMENT FOR FIRING SPARK GAPS

Abstract

The invention relates to an arrangement for firing spark gaps with a trigger electrode which is located at or in one of the main electrodes and which is insulated from this main electrode, wherein the trigger electrode can be electrically connected to a further main electrode via at least one voltage-switching or voltage-monitoring element and there is an air gap between the trigger electrode and the further main electrode, wherein the trigger electrode forms a sandwich structure with an insulating layer and a layer made of a material with lower conductivity than the material of one of the main electrodes. Moreover, the insulating layer is designed as a thin foil or lacquer layer and the layer made of the material of lower conductivity is in contact with one of the main electrodes or rests on it. According to the invention, for discharging energetically weak overvoltage events without response of the spark gap formed between the main electrodes, the insulating layer of the sandwich structure is interrupted outside the firing area and/or an electrical component which influences the response behavior is connected between the trigger electrode and the associated main electrode.

Claims

1. An arrangement for firing spark gaps with a trigger electrode (T) which is located at or in one of the main electrodes (H2) and which is insulated from this main electrode (H2), wherein the trigger electrode (T) can be electrically connected to the further main electrode (H1) via at least one voltage-switching or voltage-monitoring element (A) and there is an air gap between the trigger electrode (T) and the further main electrode (H1), wherein the trigger electrode (T) forms a sandwich structure with an insulating layer (I) and a layer made of a material (M) with lower conductivity than the material of one of the main electrodes (H1, H2), the insulating layer (I) is designed as a thin foil or lacquer layer and the layer made of the material (M) of lower conductivity is in contact with one of the main electrodes (H2) or rests on it, characterized in that for discharging energetically weak overvoltage events without response of the spark gap formed between the main electrodes (H1; H2), the insulating layer (I) of the sandwich structure is interrupted outside the firing area and/or an electrical component which influences the response behavior is connected between the trigger electrode (T) and the main electrode (H2).

2. The arrangement as claimed in claim 1, characterized in that an electrical connection between the trigger electrode (T) and the layer (M) is formed by interrupting (U) the insulating layer (I), wherein the limited conductivity or the resistance of the layer (M) determines the dischargeable energy content of the overvoltage event.

3. The arrangement as claimed in claim 1, characterized in that the electrical component is a resistor (R).

4. The arrangement according to claim 1, characterized in that in the case of low energy content of the overvoltage event, a current flows to the main electrode (H2) by way of the electrical component (R) and/or the layer (M), wherein the measure of the voltage drop at the electrical component (R) and/or at the layer (M) determines whether the overvoltage is directly discharged or whether the voltage drop results in a flashover of the insulating section (I) in the firing area or flashover area (Z) and thus in firing of the spark gap between the main electrodes (H1 and H2).

5. The arrangement according to claim 1, characterized in that the trigger electrode (T) is formed by a conductor track of a foil printed circuit board and the insulating layer (I) by an insulating cover, in particular a lacquer layer, on the conductor track, wherein the insulating cover is exposed for the interruption (U), and the exposed area is in connection with the layer (M).

6. The arrangement according to claim 1, characterized in that the layer (M) consists of a conductive plastic material.

7. The arrangement according to claim 1, characterized in that the layer (M) consists of a material with carbon fiber content.

Description

[0036] The invention is explained in greater detail hereinafter using an exemplary embodiment and with the help of figures.

[0037] In this case, in the figures:

[0038] FIG. 1 shows an equivalent circuit diagram with the principal arrangement of main electrodes of a spark gap as well as a sandwich structure, comprising a trigger electrode with an insulating layer as well as a layer made of a material of lower conductivity than the material of one of the main electrodes and a parallel connection of an electrical component in the form of a resistor between the trigger electrode and the associated main electrode and

[0039] FIG. 2 shows a representation which is similar to FIG. 1 but with an indicated interruption of the insulating layer, so that the trigger electrode comes into contact with the layer with the material of lower conductivity outside the firing area, in order to achieve a direct discharge without response of the entire spark gap in the case of low energy contents of an overvoltage event.

[0040] The representation according to FIGS. 1 and 2 comprises an electrically conductive trigger electrode T which is covered by an insulating layer I in the direction of the main electrode H2.

[0041] The insulating layer I is followed by a layer made of a material M with lower conductivity.

[0042] The layer made of the material M rests on the surface of the second main electrode H2.

[0043] External elements can be connected between the trigger electrode T and the main electrode H1 via a connection A. The means provided there may include gas arresters, varistors, diodes or similar electrical components, for example.

[0044] The spark gap formed by the main electrodes H1 and H2 can be designed as a horn spark gap and is electrically connected between the paths L and N/PEN.

[0045] The represented configuration corresponds in principle to the arrangement for plasma jet generation according to DE 10 2011 102 937 A1 and the explanations therein on the structural design. In this respect, reference is made, on the disclosure side, to the relevant explanations in DE 10 2011 102 937 A1 which embody the knowledge of the relevant person skilled in the art in this case.

[0046] According to the invention, an electrical component R which influences the response behavior is connected between the trigger electrode T and the main electrode H2 according to FIG. 1. The value of the resistor R determines the response behavior and thus an energetic limit value based on the firing process of the corresponding spark gap.

[0047] In the case of low energy contents of corresponding overvoltage events, the voltage drop which results via the resistor R is not sufficient in order to enable firing in the firing area of the arrangement. It is therefore possible to directly discharge low-energy overvoltage events by way of the arrangement of the resistor R without the main spark gap responding and aging unnecessarily as a result.

[0048] According to the representation in FIG. 2, a fully integrated solution is shown instead of the parallel connection of the resistor R.

[0049] In this respect, the thin insulating layer I is interrupted outside the firing area and flashover area, so that a conductive connection of the trigger electrode T with the material of lower conductivity M takes place. This makes it possible, owing to the resistance value of the material M, to discharge overvoltage events via the path trigger electrode, material of lower conductivity M and a main electrode H2, without this resulting in a response of the main spark gap between the electrodes H1 and H2.

[0050] In such a case, the energy content of the overvoltage is therefore so low that there is only a very small current flowing and the voltage which drops in the poorly conductive material M is not sufficient to flash over the insulating layer I. The flashover area thus does not respond and the overvoltage is discharged by the energy mapping area alone.

[0051] In contrast, if the current increases very strongly as a result of an overvoltage event such that the voltage which drops in the material M flashes over the insulating layer I and generates an ignition spark, this results in firing of the entire spark gap.

[0052] In this embodiment variant of the invention, the layer made of a material M not only has the task of extending the ignition arc by extending the direct flashover gap from the trigger electrode T to the main electrode H2, in fact the resistance value of the poorly conductive material is used via the contacting of the trigger electrode with the layer M in order to discharge weak overvoltage events. This configuration makes it possible to completely dispense with any separate electrical or electronic components for controlling the response behavior, in particular in the case of very weak overvoltage events.