# US 2017/0288371 A1 · Gas discharge tubes and methods and electrical systems including same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0288371 A1 - Document ID: US20170288371A1 - Status: Published application - Kind: A1 - Application number: 15/089,294 - Filed: 2016-04-01 - Published: 2017-10-05 - Earliest claimed: 2016-04-01 - Assignees: Ripd Research and IP Development Ltd. - Applicants: RIPD Research and IP Development Ltd. - Inventors: Robert Rozman - Web page: https://patentgrep.com/patent/US20170288371A1 ## CPC - H01T 4/04: Housings (H01T4/06 takes precedence) - H01T 4/08: structurally associated with protected apparatus (with switches H01H9/14; with fuses H01H85/44) - H01T 2/02: comprising a trigger electrode or an auxiliary spark gap - H01T 4/12: hermetically sealed - H01T 4/16: having a plurality of gaps arranged in series - H01T: SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES (overvoltage protection circuits H02H) ## Abstract A gas discharge tube includes a housing defining a chamber, first and second terminal electrodes mounted on the housing, a plurality of inner electrodes located in the chamber, and a gas contained in the chamber. The inner electrodes are serially disposed in the chamber in spaced apart relation to define a series of spark gaps from the first terminal electrode to the second terminal electrode. The chamber is hermetically sealed. ## Claims ### Claim 1 A gas discharge tube comprising: a housing defining a chamber; first and second terminal electrodes mounted on the housing; a plurality of inner electrodes located in the chamber; a gas contained in the chamber; wherein the inner electrodes are serially disposed in the chamber in spaced apart relation to define a series of spark gaps from the first terminal electrode to the second terminal electrode; and wherein the chamber is hermetically sealed. ### Claim 2 (depends on 1) The gas discharge tube of claim 1 wherein the plurality of inner electrodes includes at least three electrodes defining at least four spark gaps. ### Claim 3 (depends on 1) The gas discharge tube of claim 1 wherein the housing includes an insulator and a cover forming the housing and defining the chamber, and the insulator is formed of an electrically insulating material. ### Claim 4 (depends on 3) The gas discharge tube of claim 3 wherein the cover is electrically conductive. ### Claim 5 (depends on 1) The gas discharge tube of claim 1 wherein at least some of the inner electrodes are curved plates. ### Claim 6 (depends on 1) The gas discharge tube of claim 1 wherein the inner electrodes are captured in the chamber to permit limited displacement between the housing and the inner electrodes. ### Claim 7 (depends on 1) The gas discharge tube of claim 1 further comprising a trigger device that is contained in the housing and that is electrically conductively coupled to either one of the first terminal electrode or the second terminal electrode and to ones of the plurality of inner electrodes. ### Claim 8 (depends on 7) The gas discharge tube of claim 7 wherein the trigger device is disposed in the chamber. ### Claim 9 (depends on 7) The gas discharge tube of claim 7 wherein the trigger device includes: a substrate formed of an electrically insulating material; and a plurality of resistor links mounted on the substrate; wherein the resistor links are configured to conduct current from the inner electrodes. ### Claim 10 (depends on 9) The gas discharge tube of claim 9 wherein the trigger device includes holes defined in the substrate to permit electrical connection between the resistor links and the inner electrodes. ### Claim 11 (depends on 9) The gas discharge tube of claim 9 wherein each of the resistor links includes a resistor layer bonded to the substrate, the resistor layer being formed of an electrically resistive material. ### Claim 12 (depends on 11) The gas discharge tube of claim 11 wherein the electrically resistive material includes graphite in an adhesive carrier. ### Claim 13 (depends on 11) The gas discharge tube of claim 11 wherein: each of the resistor links further includes a terminal interface layer between the resistor layer thereof and the inner electrode associated with the resistor link; and the terminal interface layer is formed of metal. ### Claim 14 (depends on 9) The gas discharge tube of claim 9 wherein each of the resistor links has a resistance value in the range of from about 3 to 500 ohm. ### Claim 15 (depends on 9) The gas discharge tube of claim 9 wherein the trigger device includes integral locator features that secure the inner electrodes in position in the chamber. ### Claim 16 (depends on 9) The gas discharge tube of claim 9 wherein the trigger device includes: first and second substrates each formed of an electrically insulating material; at least one resistor link mounted on the first substrate; and at least one resistor link mounted on the second substrate; wherein the resistor links are configured to conduct current from the inner electrodes. ### Claim 17 (depends on 16) The gas discharge tube of claim 16 wherein the second substrate is stacked on the first substrate. ### Claim 18 (depends on 1) The gas discharge tube of claim 1 wherein the housing includes integral locator features that secure the inner electrodes in position in the chamber. ### Claim 19 (depends on 1) The gas discharge tube of claim 1 wherein: the housing includes a partition wall that divides the chamber into fluidly connected first and second subchambers; the first terminal electrode is disposed in the first subchamber; the second terminal electrode is disposed in the second subchamber; and some of the inner electrodes are disposed in the first subchamber and some of the inner electrodes are disposed in the second subchamber. ### Claim 20 (depends on 1) The gas discharge tube of claim 1 wherein: the inner electrodes are concentric, cylindrically-shaped plates; and the second terminal includes an annular wall concentric with and circumferentially surrounding the inner electrodes. ### Claim 21 (depends on 1) The gas discharge tube of claim 1, wherein the gas contained in the chamber comprises helium. ### Claim 22 (depends on 21) The gas discharge tube of claim 21, wherein the helium gas is present in the chamber in an amount of at least 50% by volume of the total volume of gas in the chamber. ### Claim 23 (depends on 21) The gas discharge tube of claim 21, wherein the gas contained in the chamber comprises a mixture of helium and at least one other gas. ### Claim 24 A method comprising: electrically conductively coupling a first terminal electrode to a phase line of a power system and a second terminal electrode to a neutral line of a power system; providing a plurality of inner electrodes that are arranged between first terminal electrode and the second terminal electrode and that are spaced apart from one another; and electrically conductively coupling a plurality of resistors between respective ones of the plurality of inner electrodes and the second terminal electrode. ### Claim 25 (depends on 24) The method of claim 24, wherein the providing the plurality of inner electrodes comprises arranging the plurality of inner electrodes to define a plurality of spark gaps between the first electrode and a first one of the plurality of the inner electrodes, between ones of the plurality of inner electrodes and between a second one of the plurality of inner electrodes and the second terminal. ### Claim 26 (depends on 25) The method of claim 25, wherein responsive to a system operating voltage being present on the phase line, no current flows between the first terminal electrode and the second terminal, and wherein responsive to an overvoltage condition being present on the phase line, a current flows from the first terminal electrode to the second terminal electrode. ### Claim 27 (depends on 26) The method of claim 26, wherein the current that flows from the first terminal electrode to the second terminal electrode flows across the plurality of spark gaps. ### Claim 28 (depends on 24) The method of claim 24, further comprising providing a housing that defines a chamber, wherein the first terminal electrode and the second terminal electrode are mounted on the housing, wherein the plurality of inner electrodes are located in the chamber, and wherein the plurality of resistors are located in the chamber. ### Claim 29 An overvoltage protection circuit comprising: at least one housing defining at least one hermetically sealed chamber; a series of spaced apart electrodes defining a series of spark gaps therebetween located in the at least one chamber; and a gas contained in the at least one chamber; wherein the gas contained in the at least one chamber includes helium.