RU64822U1 - SMALL DISCHARGE - Google Patents

Abstract

The invention relates to the design of spark arresters used as protective elements of radio frequency paths from surge pulses. A small-sized arrester with a coaxial arrangement of electrodes, consists of a cylindrical electrically conductive body, on the inner surface of which an external electrode having the shape of a torus is fixed, two insulators forming an airtight discharge chamber with a body, an electrically conductive rod with an internal electrode having a disk shape fixed to it and located relative to it external electrode so that they form a spark gap in the form of a ring, the conductive rod passes s volume through the discharge chamber through the centers of the first and second insulators, and the radius of the electrically conductive rod has a value determined by the relationship:

r = R / 10 ^{(ρ / 138)} ;

where: r is the radius of the conductive rod, mm;

R is the inner radius of the cylindrical body, mm;

ρ - wave impedance of the protected communication line, Ohm,

ρ / 138 - ratio for providing wave resistance of 50 Ohms.

The technical result to which the claimed invention is directed is to expand the functionality by providing the possibility of using a spark gap to protect radio frequency communication lines from overvoltage.

Description

The invention relates to the design of spark arresters used as protective elements of radio frequency paths from surge pulses.

Known small discharger [1] with a coaxial arrangement of electrodes, containing a cylindrical electrically conductive housing, on the inner surface of which is fixed an external electrode having the shape of a torus, an insulator, an electrically conductive rod with an internal electrode fixed to it, having a disk shape and located relative to the external electrode in such a way that, they form a spark discharge gap in the form of a ring.

In such a spark gap, a multichannel spark breakdown occurs and the resulting inductance of the parallel spark channels has a sufficiently small value, which ensures high speed of the spark gap.

The disadvantage of such a spark gap is its narrow functionality, limited by the scope of its use as a switching gap in pulsed electrical installations.

The technical result to which the claimed invention is directed is to expand the functionality by providing the possibility of using a spark gap to protect radio frequency communication lines from overvoltage.

To achieve the specified technical result in a small-sized spark gap with a coaxial arrangement of electrodes containing a cylindrical electrically conductive housing, on the inner surface of which an external electrode is fixed, having the shape of a torus, an insulator, an electrically conductive rod with an internal electrode fixed to it,

having a disk shape and positioned relative to the external electrode in such a way that they form a spark gap in the form of a ring, a second insulator is introduced, forming a sealed discharge chamber with the housing and the first insulator, the electrically conductive rod passes through the internal volume of the discharge chamber through the centers of the first and second insulators, moreover, the radius of the conductive rod has a value determined from the ratio:

where: r is the radius of the conductive rod, mm;

R is the inner radius of the cylindrical electrically conductive housing, mm;

ρ - wave impedance of the protected communication line, Ohm,

ρ / 138 - ratio for providing wave resistance of 50 Ohms.

The distinctive features of the proposed small-sized spark gap from the specified known closest to it are the presence of a second insulator, the passage of the conductive rod through the internal volume of the spark gap, as well as the established relationship between the inner radius of the cylindrical electrically conductive housing and the diameter of the inner electrode.

Due to the fact that structurally the arrester is essentially a segment of a coaxial cable line, it can be included in the gap of the protected coaxial radio frequency communication line. The ratio of the radii of a cylindrical electrically conductive housing and an electrically conductive rod established by formula (1) ensures coordination of the arrester with the protected communication line by wave impedance.

A sketch of the proposed arrester is shown in figure 1.

A small-sized spark gap consists of an electrically conductive cylindrical body 1, closed on both sides by ring insulators 2 and 3, through the central openings of which passes an electrically conductive rod 4 with a disk-shaped internal electrode 5 perpendicular to it. An external electrode 6, having the shape of a torus, is fixed inside the cylindrical body 1 in such a way that together with the internal electrode 5 it forms a spark gap 7 in the form of a ring.

The rated sportsman works as follows. The arrester included in the rupture of the radio frequency communication line is matched with it in terms of wave impedance and under normal operating conditions does not affect the operation of the radio equipment. When an electrical impulse appears in the radio frequency communication line, it enters the arrester input. Inside the spark gap, a voltage wave propagates from the electrically conductive rod 4 to the surface of the inner electrode, which is in the form of a disk 5, and then radially to its periphery. To the edge of the disk 5, the pulse front approaches simultaneously around the entire perimeter and creates a potential difference in the spark gap 7. When the voltage on the spark gap reaches a value sufficient for its breakdown, the arrester is triggered. Since the potential difference and the size of the spark gap are uniform along its perimeter, the breakdown occurs in several places and several conducting channels are formed. The current of electrical pickup quickly spreads along the formed channels and the amplitude-time, and hence the energy parameters of the interference pulse, coming further through the communication line to the equipment, are significantly reduced. After the end of the voltage pulse, the normal functioning of the equipment continues.

Thus, thanks to the acquired ability of the arrester to be used to protect radio frequency communication lines, the functionality of its application is expanded.

Literature:

1. EF Balbonenko et al. High-current spark gap with a sharply inhomogeneous electric field. Instruments and experimental equipment, 1997, No. 6, p. 86-91. UDC 621.316.933

Claims (1)

A small-sized spark gap with a coaxial arrangement of electrodes, containing a cylindrical electrically conductive housing, on the inner surface of which is fixed an external electrode having the shape of a torus, an insulator, an electrically conductive rod with an internal electrode that has a disk shape and is located relative to the external electrode so that they form a spark a discharge gap in the form of a ring, characterized in that a second insulator is introduced, forming a sealed discharge with the housing and the first insulator th camera, electrically conductive rod extends the internal volume of the discharge chamber completely through the centers of the first and second insulators, the ratio of the radii of the cylindrical body and electrically conductive rod aligns with the arrester protected communication line characteristic impedance.