Triggered spark gap

FIELD: electricity.

SUBSTANCE: surge arrester has a trigatron structure and contains the anode (3) and cathode (1) with axial bore where a control electrode (2) is placed in the form of a rod separated from the cathode by an insulator (4). The control electrode is placed at the same level with cathode and a ceramic insulator is placed outside the spark gap of the cathode and control electrode. At the inner surface of the ceramic insulator having diameter of the opening equal to the control electrode diameter there is a trigger coating (5) based, for example, on colloidal graphite.

EFFECT: improvement of durability and reliability of the triggered spark gap within a wide range of operating voltages, reduction of pulse amplitude for the control voltage and reduction of breakdown delay time.

2 dwg, 1 tbl

The invention relates to gas-discharge technique and can be used to create managed arresters trigatron type with a stable operating voltage range with great durability for the formation of the switching current pulse.

Known controlled discharger trigatron type containing an anode and a cathode, is made with an axial cylindrical bore in which you installed the Manager rod electrode, separated from the cathode insulator. (Kiselev J.V., Cherepanov VP Spark arrestors. M., "Soviet radio", 1976, p.12-17).

The disadvantage of this design of the spark gap is small relative durability when switching high-current pulses. In the process of mode switching of high-current pulse occurs the destruction of the insulating sleeve and consequently the reduction of the electric strength of the discharge gap anode-cathode, the narrowing of the range of operating voltages and the increase in the pulse amplitude of the control voltage. The durability of such a spark gap when working in this mode is not more than 8×10⁵discharge.

Closest to the proposed invention constructive characteristic is controlled discharger containing high-voltage electrode and a grounded electrode in the axial hole of which is a control electrode in widescreen. In this arrangement, the insulator between the cathode and control electrode are made of the discharge gap, and the cathode is made with a Central hole in the form of a cylinder, rolling in an expanding cone, or in the form of a Cup with a Central cutout. The control electrode is at the level of the working surface of the cathode. In this case, in the process of beam control electrode sprayed layers, preserving its appearance close to the original, until the beginning of the tapered portion of the neck of the cathode or the inside edge of the neck of the cathode, is made in the form of a Cup. The durability of the spark gap of this structure is not more than 2×10⁶breakthroughs. (Shkuropat P.I. Electrical characteristics controlled spark gaps in air with a powerful ignition, ZH, 1966, XXXVI, s).

The disadvantage of this construction is that when spraying the control electrode until the beginning of the tapered portion of the neck of the cathode or the inside edge of the neck of the cathode, made in the form of cups, the breakdown period of the cathode-control electrode is at a depth of cut of the cathode. This leads to gaps in the breakdown of the main gap anode-cathode and for a breakdown of the main gap it is necessary to increase the pulse amplitude of the control voltage and the minimum voltage of the anode. In further work the minimum anode voltage increases sharply, the passes of the breakdown of the main gap is observed up to the maximum voltage of the anode.

All these designs arresters were performed with an optimal ratio of the interelectrode gaps (A.S. No. 605279 CL NT 3/00 1978).

The purpose of the invention is to improve durability and reliability of a spark gap in a wide range of operating voltages, reducing the pulse amplitude control voltage and reduction in time lag of breakdown.

The technical result is achieved by coating the inner surface of the ceramic insulator initiating coverage, for example, colloidal graphite of the drug, which leads to a decrease in the amplitude of a control voltage pulse, the time lag of breakdown, preventing the growth of the minimum voltage of the anode and a sharp increase in the durability of the spark gap.

This technical result in the implementation of the invention is achieved in that in the known controlled discharger containing opposing anode and cathode, is made with a Central hole in the form of a cylinder by rolling into a cone or Cup with a Central hole, in which the axis is set Manager rod located on the same level as the cathode and separated from it by a ceramic insulator made of the bit period of the cathode-control electrode on the inner surface of the ceramic insulator with the diameter of the m hole, equal to the diameter of the control electrode caused initiating the floor, not shorting period of the cathode-control electrode, for example, colloidal graphite of the drug.

Conducted by the applicant's analysis of the level of technology has allowed to establish that the applicant is not detected similar, characterized by signs, identical to all the essential features of the claimed invention, and the definition from the list of identified unique prototype, as the most similar set of features analogue, has allowed to identify a set of existing in relation to perceived by the applicant to the technical result of the distinctive features set forth in the claims. Therefore, the claimed invention meets the requirement of "novelty" under the current law.

To verify compliance of the claimed invention to the requirement of inventive step, the applicant conducted an additional search of the known solutions, the results of which show that the claimed invention is not necessary for the expert in the obvious way from the prior art, because it is not identified solutions to improve the durability and reliability of a managed device in a wide range of operating voltages, reducing the pulse amplitude control voltage, reducing the lag time is of robot, it would be used in initiating the floor, not shorting period of the cathode-control electrode, for example, colloidal graphite of the drug deposited on the inner surface of a ceramic insulator having a bore diameter equal to the diameter of the control electrode.

Therefore, the claimed invention meets the requirement of "inventive step" by applicable law.

The invention is illustrated in the drawing. Figure 1(a, b) is a schematic managed arresters with different cathodes and ceramic insulators.

The discharger has trigatron design and includes an anode 3 and the cathode 1, is made with an axial hole, which has a control electrode 2 in the form of a rod, separated from the cathode insulator 4. The control electrode is flush with the cathode, and a ceramic insulator made of the bit period of the cathode-control electrode. On the inner surface of a ceramic insulator having a bore diameter equal to the diameter of the control electrode caused initiating the floor, for example, colloidal graphite preparation 5.

The discharger operates as follows: between the anode and cathode of the spark gap, direct voltage, the cathode of the spark gap grounded. When applying a pulse control on the Directive there is a breakdown of the amount of anode-cathode in a given range of operating voltages with the pulse frequency of the control voltage.

Comparative testing of arresters on durability showed the advantages of the construction and application of coatings on the inner surface of the ceramic insulator in comparison with dischargers with conventional insulators. Table 1 presents data on the change of parameters obtained from these tests:

for example, colloidal graphite coating on the inner surface of the ceramic insulator with a hole diameter equal to the diameter of the control electrode (1);

without colloidal graphite coating (2).

From the table it is clear that the initiating application of the coating on the inner surface of the ceramic insulator increases the durability of the spark gap at least 4 times, reduces the pulse amplitude control voltage, and reduces and stabilizethe delay time of the breakdown.

This is because when applying the pulse to the control electrode under tension falls and initiating the floor, for example, colloidal graphite of the drug. On the border initiating coverage-insulator due to the micro gaps arising due to the porosity of ceramics, there is a significant distortion of the electric field and, consequently, increasing the tension. The conditions for the field emission of electrons in the interelectrode gaps, which in turn prevents the growth of the amplitude of a control voltage pulse and increases the durability of the spark gap, at least four times.

Therefore, the claimed invention meets the requirement of "industrial applicability" under the current law.

Managed discharger containing opposing anode and cathode, is made with a Central hole in the form of a cylinder by rolling into a cone or Cup with a Central hole, in which the axis is set Manager rod located on the same level as the cathode and separated from it by a ceramic insulator made of the bit period of the cathode-control electrode, characterized in that on the inner surface of a ceramic insulator having a bore diameter equal to the diameter of the control electrode, Nanase is about initiating the floor, not shorting period of the cathode-control electrode, for example, colloidal graphite of the drug.