EP0769832A1 - Tube de decharge a surface de decharge revetue - Google Patents

Tube de decharge a surface de decharge revetue Download PDF

Info

Publication number
EP0769832A1
EP0769832A1 EP96912300A EP96912300A EP0769832A1 EP 0769832 A1 EP0769832 A1 EP 0769832A1 EP 96912300 A EP96912300 A EP 96912300A EP 96912300 A EP96912300 A EP 96912300A EP 0769832 A1 EP0769832 A1 EP 0769832A1
Authority
EP
European Patent Office
Prior art keywords
discharge
wgt
voltage
coating material
discharge tube
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP96912300A
Other languages
German (de)
English (en)
Other versions
EP0769832A4 (fr
Inventor
Kazuhiko Machida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shinko Electric Industries Co Ltd
Original Assignee
Shinko Electric Industries Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shinko Electric Industries Co Ltd filed Critical Shinko Electric Industries Co Ltd
Publication of EP0769832A1 publication Critical patent/EP0769832A1/fr
Publication of EP0769832A4 publication Critical patent/EP0769832A4/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T1/00—Details of spark gaps
    • H01T1/20—Means for starting arc or facilitating ignition of spark gap
    • H01T1/22—Means for starting arc or facilitating ignition of spark gap by the shape or the composition of the electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T4/00—Overvoltage arresters using spark gaps
    • H01T4/10—Overvoltage arresters using spark gaps having a single gap or a plurality of gaps in parallel
    • H01T4/12—Overvoltage arresters using spark gaps having a single gap or a plurality of gaps in parallel hermetically sealed

Definitions

  • the present invention relates to a discharge tube suitably used as an arrester or a spark gap for supplying a constant voltage to an ignition plug, a high-voltage discharge lamp or the like, and more particularly relates to a discharge tube with a coating material applied on the discharge surfaces thereof.
  • Conventionally known discharge tube devices include an arrester mounted on a commercial power line to equipment for preventing intrusion of a spontaneous surge voltage caused by thunder or a spark gap used with a vehicle ignition plug or a high-voltage discharge lamp for continuously supplying a constant high-voltage. It is a common practice to apply various types of coating material on the discharge surfaces of the electrodes of the discharge tubes in order to minimize the initial break-down voltage against a surge voltage for the arrester or in order to produce a stable discharge voltage for the spark gap.
  • a spark gap which has a function of maintaining the discharge voltage below a predetermined level, can, of course, be used as an arrester.
  • the most generally known conventional coating material is composed of water as a solvent, sodium silicate, nitrocellulose or silicon rubber as a fixing agent to which barium titanate or aluminum oxide is added for improving the surge resistance.
  • the discharge tube with the above-mentioned additives applied on the discharge surfaces thereof has a disadvantage in that, when the rise time of the input surge voltage is shortened, the breakdown voltage increases and the function of an arrester or a spark gap cannot be fully exhibited.
  • the present invention has been developed to obviate the above-mentioned problems, and a first object of the invention is to provide a discharge tube capable of producing a stable discharge voltage even with a surge pulse having a short rise time.
  • a second object of the invention is to provide a discharge tube capable of producing a stable discharge voltage even after continuous discharge.
  • a discharge tube configured as described below.
  • a discharge tube comprises two electrodes arranged in opposed relation to each other with an insulating member between them for causing a discharge in the gap formed between the two opposed discharge surfaces of the electrodes, wherein a coating material containing 0.01 to 60 wgt % of at least one alkali metal salt selected from potassium bromide, potassium fluoride and sodium fluoride is applied on the discharge surfaces of the two electrodes.
  • This configuration can produce a stable discharge voltage even against a surge voltage having a short rise time.
  • the alkali metal salt contained in the coating material is preferably 5 to 30 wgt %, or especially 10 to 20 wgt %.
  • the sodium silicate contained in the coating material is preferably 0.5 to 10 wgt %, or more preferably 1 to 2.5 wgt %.
  • Fig. 1 is a sectional view of a discharge tube according to the present invention.
  • Fig. 2 is a graph showing a voltage-time characteristic curve of a discharge tube (with a coating material containing potassium bromide) according to the first embodiment of the invention.
  • Fig. 3 is a graph showing a continuous discharge characteristic (indicating the upper and lower limits of the wave) with high-voltage pulses continuously applied to the discharge tube of Fig. 2.
  • Fig. 4 is a graph showing a voltage-time characteristic curve of a discharge tube (using a coating material containing sodium silicate and potassium bromide) according to a second embodiment of the invention.
  • Fig. 5 is a graph showing a continuous discharge characteristic (indicating the upper and lower limits of the wave) of the discharge tube of Fig. 4 continuously supplied with high-voltage pulses.
  • Fig. 6 is a graph showing a continuous discharge characteristic (indicating the upper and lower limits of the wave) of the discharge tube of Fig. 4 supplied with a continuous train of high-voltage pulses followed by another continuous train of high-voltage pulses.
  • Fig. 7 is a graph showing a continuous discharge characteristic (indicating the upper and lower limit of the wave) of a discharge tube supplied with high-voltage pulses according to a third embodiment of the invention.
  • Fig. 8 is a graph showing a continuous discharge characteristic (indicating the upper and lower limits of the wave) of a discharge tube supplied with high-voltage pulses according to a fourth embodiment of the invention.
  • Fig. 9 is a sectional view showing a configuration of the electrode section of a discharge tube according to another embodiment of the invention.
  • Fig. 10 is a graph showing a voltage-time characteristic curve of a conventional discharge tube supplied with high-voltage pulses.
  • Fig. 11 is a graph showing a continuous discharge characteristic (indicating the upper and lower limits of the wave) of an example of a conventional discharge tube using a coating material containing sodium silicate of 25 wgt % and barium titanate of 5 wgt %.
  • Fig. 12 is a graph showing a continuous discharge characteristic (indicating the upper and lower limits of the wave) of an example of a conventional discharge tube using a coating material containing sodium silicate of 6 wgt % and barium titanate of 3.5 wgt % applied thereto.
  • Fig. 10 is a graph showing a voltage-time characteristic curve of a discharge tube with a coating material containing sodium silicate and barium titanate applied to the discharge surfaces thereof as an example.
  • the ordinate represents the break-down voltage with a surge pulse voltage applied
  • the abscissa represents the duration of a surge pulse applied.
  • the rise time (in voltage/time) of a surge pulse is also shown.
  • This graph indicates the change of an actual break-down voltage with respect to the change of the surge pulse duration and the rise time of a discharge tube designed for a predetermined break-down time.
  • the voltage-time characteristics of discharge tubes having break-down voltages of 600 volts, 350 volts and 200 volts are shown as an example of a specification.
  • Fig. 11 shows the initial discharge characteristic (continuous discharge characteristic) of a discharge tube using a coating material containing sodium silicate of 25 wgt % and barium titanate of 5 wgt % supplied with high-voltage pulses of 5 msec. duration.
  • Fig. 12 shows an initial discharge characteristic (continuous discharge characteristic) of a discharge tube using a coating material containing sodium silicate of 6 wgt % and barium titanate of 3.5 wgt % supplied with high-voltage pulses of 5 msec. duration.
  • Neither of the discharge tubes could produce a stable continuous break-down voltage.
  • Fig. 1 is a sectional view showing an embodiment of a discharge tube 10.
  • Numeral 12 designates a cylindrical insulating member composed of a ceramic such as alumina. Electrodes 14a, 14b are fixed in opposed relation to each other by silver solder to the end openings of the cylindrical insulating member 12, and a low-pressure inert gas, such as argon or the like, is sealed in the hermetic insulating member 12.
  • a low-pressure inert gas such as argon or the like
  • a carbon trigger line (not shown) is formed at appropriate points on the inner wall of the insulating member 12 for stabilizing the initial discharge.
  • the electrodes 14a, 14b composed of iron-nickel alloy, iron-nickel-cobalt alloy or copper include discharge surfaces 17a, 17b, respectively, to discharge in a gap 20 between the opposed discharge surfaces 17a, 17b.
  • a coating material 16 is applied on the discharge surfaces 17a, 17b.
  • the coating material 16 using water (pure water) as a solvent is produced by adding a solvent containing 0.01 to 60 wgt % of potassium bromide constituting an alkali metal salt to a well-known coating material using barium titanate.
  • the coating material 16 is coated and dried on the discharge surface.
  • Fig. 2 is a graph showing a voltage-time characteristic curve of a specific example of the first embodiment (a discharge tube using a coating material containing barium titanate as a main component and 10 wgt % of potassium bromide).
  • the break-down voltage of a 200-V spark gap does not increase as rapidly as that of the conventional discharge tube.
  • the discharge operation can thus be started at about 430 V with the rise time of 10 KV/msec, thus exhibiting a superior characteristic as an arrester. Consequently, the equipment can be positively protected and is liable to be broken at a lower rate.
  • Potassium bromide has a direct effect on the stability of the discharge voltage, and is usable in the range of 0.01 to 60 wgt %.
  • the discharge characteristic becomes stable in the range of 5 to 30 wgt %, or especially, the stability is improved in the range of 10 to 20 wgt % of potassium bromide.
  • Other alkali metal salts such as potassium fluoride or sodium fluoride, may be used in place of potassium bromide. At least one of these three alkali metal salts may be contained in the coating material with equal effect.
  • the discharge tube 10 according to the first embodiment cannot maintain a stable, constant discharge voltage in the case where high-voltage pulses of 5 msec. or less in duration are continuously applied as the initial discharge characteristic (continued discharge characteristic).
  • the discharge tube 10 therefore cannot be used as a spark gap.
  • the discharge tube 10 has a similar mechanical structure to the structure shown in Fig. 1.
  • the coating material contains sodium silicate as a fixing agent.
  • the coating material 16 uses water (pure water) as a solvent.
  • the solvent contains 0.01 wgt % of sodium silicate and 0.01 to 60 wgt % of potassium bromide.
  • the coating material 16 is applied and dried on the discharge surfaces.
  • the effect of the added sodium silicate begins to be exhibited from about 0.01 wgt %, and the discharge characteristic is most stable in the range of 1 to 2.5 wgt %.
  • the stability of the discharge characteristic is gradually reduced for the content more than 2.5 wgt %.
  • the content exceeds 40 wgt %, a dynamic current discharge easily occurs. Therefore, the effect can be sustained up to 50 wgt % of sodium silicate which is an upper limit of the amount of sodium silicate that can be dissolved in the solvent water.
  • the content of sodium silicate should be maintained on the order of several percent as far as possible
  • Fig. 4 is a graph showing the voltage-time characteristic curve of a specific example (sodium silicate of 2.5 wgt % and potassium bromide of 10 wgt %) according to the second embodiment.
  • Fig. 5 shows the initial discharge characteristic of a spark gap supplied with a high-voltage pulse not more than 5 msec., having the discharge surfaces on which a coating material containing 2.5 wgt % of sodium silicate and 15 wgt % of potassium bromide is prescribed and applied.
  • the coating material contains not only potassium bromide but also sodium silicate, the initial discharge characteristic (continuous discharge characteristic) as well as the voltage-time characteristic shown in Fig. 4 can be stabilized at 1000 V or thereabouts for the break-down voltage.
  • the initial discharge characteristic (continuous discharge characteristic) with high-voltage pulses of 5 msec. or less continuously applied is stabilized at about 1000 V as shown in Fig. 5.
  • the discharge tube thus can be used not only as an arrester but also as a spark gap.
  • Fig. 6 shows the discharge characteristic after applying a high-voltage pulse of 5 msec. or less 20000 times each for one second to the same discharge tube as the one described above. As can be seen from Fig. 6, the break-down voltage is maintained at 1000 V and a stable discharge characteristic is exhibited even after continuous long-time operation.
  • the configuration of a discharge tube according to the third embodiment is substantially the same as that of the discharge tube 10 described with reference to Fig. 1, the only difference being the composition of the coating material 16.
  • the coating material 16 uses water as a solvent which contains 0.01 to 50 wgt % of sodium silicate and 0.01 to 60 wgt % of potassium fluoride. The coating material 16 is applied and dried on the discharge surfaces.
  • the amount of sodium silicate added is the same as that explained with reference to the second embodiment and will not be described.
  • Potassium fluoride has a direct effect on the stability of the discharge voltage and can be used in the range of 0.01 to 60 wgt %.
  • the discharge characteristic is stable with 5 to 30 wgt % of potassium fluoride, or preferably about 10 to 20 wgt % at which high stability is obtained.
  • Fig. 7 shows the initial discharge characteristic (continuous discharge characteristic) obtained when a high-voltage pulse of 5 msec. or less is impressed on a spark gap using a coating material containing 2.5 wgt % of sodium silicate and 15 wgt % of potassium fluoride prescribed and applied on the discharge surfaces thereof.
  • the break-down voltage is stable at about 1000 V.
  • the discharge characteristic of this discharge tube obtained after high-voltage pulses of 5 msec. or less are impressed 20000 times each time for one second is found to be stable, though not shown.
  • the break-down voltage of 1000 V is maintained even after long-term continuous discharge in the same manner as the discharge tube of the second embodiment.
  • the voltage-time characteristic curve, though not shown, is also substantially similar to that of the second embodiment.
  • the configuration of a discharge tube according to the fourth embodiment is substantially the same as that of the discharge tube 10 described with reference to the first embodiment, the only difference being the composition of the coating material 16.
  • the coating material 16 uses water as a solvent and contains 0.01 to 50 wgt % of sodium silicate and 0.01 to 60 wgt % of sodium fluoride. The coating material 16 is applied and dried on the discharge surfaces.
  • the amount of the sodium silicate added is the same as that explained with reference to the second embodiment and will not be explained.
  • Sodium fluoride has a direct effect on the stability of the discharge voltage, and is usable in the range of 0.01 to 60 wgt %.
  • the content of 5 to 30 wgt % produces a stable discharge characteristic, and the content of 10 to 20 wgt % is more preferable as the stability is further improved.
  • Fig. 8 shows the initial discharge characteristic obtained when high-voltage pulses of 5 msec. or less are applied to a discharge tube using a coating material 16 containing 2.5 wgt % of sodium silicate and 15 wgt % of sodium fluoride prepared and applied on the discharge surfaces thereof.
  • the break-down voltage is stabilized at about 1000 V.
  • the discharge characteristic obtained after applying high-voltage pulses of 5 msec. or less in 20000 cycles each one second in length indicates that a break-down voltage of 1000 V and a stable discharge characteristic are maintained even after long-term continuous use in the same manner as the discharge tube of the first embodiment. Also, the voltage-time characteristic, though not shown, is substantially identical to that of the second embodiment.
  • potassium bromide, potassium fluoride or sodium fluoride is used as an alkali metal salt contained together with sodium silicate in the coating material 16.
  • the coating material 16 may contain a mixture of a plurality of alkali metal salts with equal effect, including a combination of potassium bromide and potassium fluoride, a combination of potassium bromide and sodium fluoride, a combination of potassium fluoride and sodium fluoride or a combination of potassium bromide, potassium fluoride and sodium fluoride.
  • each alkali metal salt in the coating material 16 may be in the range of 0.01 to 60 wgt % as in the case where only one type of alkali metal salt is used with sodium silicate. Nevertheless, the discharge characteristic is stabilized in the range of 5 to 30 wgt % or preferably in the range of 10 to 20 wgt % where an especially high stability is obtained.
  • the coating material 16 is prepared to contain 2.5 wgt % of sodium silicate, 15 wgt % of potassium bromide and 15 wgt % of potassium fluoride.
  • the coating material 16 preferably has the contents of 2.5 wgt % of sodium silicate, 15 wgt % of potassium bromide, 15 wgt % of potassium fluoride and 15 wgt % of sodium fluoride.
  • the coating material according to this invention can be applicable to a triode discharge tube and the like.
  • a recess 18 may be formed in the discharge surface of each electrode as shown in Fig. 9. This configuration can assure a large surface area contributing to a longer service life.
  • a discharge tube in which a stable break-down voltage can be obtained even with a short rise time of the surge voltage.
  • the discharge tube according to the invention can be used as an arrester, thereby preventing the equipment involved from being damaged.
  • the coating material contains sodium silicate at the same time, a stable break-down voltage is obtained even when high-voltage, high-frequency pulses are applied continuously.
  • the present invention therefore, can exhibit a superior characteristic even when used for a vehicle ignition plug or a high-voltage discharge lamp.

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Paints Or Removers (AREA)
EP96912300A 1995-05-02 1996-05-01 Tube de decharge a surface de decharge revetue Withdrawn EP0769832A4 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP108464/95 1995-05-02
JP10846495 1995-05-02
JP06754296A JP3749754B2 (ja) 1995-05-02 1996-03-25 放電管
JP67542/96 1996-03-25
PCT/JP1996/001200 WO1996035249A1 (fr) 1995-05-02 1996-05-01 Tube de decharge a surface de decharge revetue

Publications (2)

Publication Number Publication Date
EP0769832A1 true EP0769832A1 (fr) 1997-04-23
EP0769832A4 EP0769832A4 (fr) 1998-07-15

Family

ID=26408765

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96912300A Withdrawn EP0769832A4 (fr) 1995-05-02 1996-05-01 Tube de decharge a surface de decharge revetue

Country Status (5)

Country Link
EP (1) EP0769832A4 (fr)
JP (1) JP3749754B2 (fr)
KR (1) KR100206035B1 (fr)
CA (1) CA2194212A1 (fr)
WO (1) WO1996035249A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0938173A1 (fr) * 1998-02-20 1999-08-25 Shinko Electric Industries Co. Ltd. Tube à décharge à éclateur de conmutation
EP1918600A1 (fr) 2006-10-30 2008-05-07 Valeo Embrayages Embrayage pour véhicules automobiles à moyens de centrage du cordon rampe sur le plateau de pression
CN103594304A (zh) * 2013-11-21 2014-02-19 四川天微电子有限责任公司 放电管点火装置
WO2022212376A1 (fr) * 2021-03-29 2022-10-06 The Regents Of The University Of California Revêtement blanc froid pulvérisable à base de microsphères de céramique

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2537964A1 (de) * 1975-08-26 1977-03-10 Siemens Ag Gasentladungsroehre, insbesondere ueberspannungsableiter

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2735865C3 (de) * 1977-08-09 1980-10-16 Siemens Ag, 1000 Berlin Und 8000 Muenchen Gasentladungs-Überspannungsableiter
JPS5537709A (en) * 1978-09-07 1980-03-15 Shiroyama Seisakusho Kk Communication atmospheric discharge arrester
DE3335602A1 (de) * 1983-09-30 1985-04-18 Siemens AG, 1000 Berlin und 8000 München Gasentladungsableiter und herstellungsverfahren
DE3621254A1 (de) * 1986-06-25 1988-01-07 Siemens Ag Gasentladungsueberspannungsableiter
JP2573908Y2 (ja) * 1992-10-06 1998-06-04 矢崎総業株式会社 放電管

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2537964A1 (de) * 1975-08-26 1977-03-10 Siemens Ag Gasentladungsroehre, insbesondere ueberspannungsableiter

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9635249A1 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0938173A1 (fr) * 1998-02-20 1999-08-25 Shinko Electric Industries Co. Ltd. Tube à décharge à éclateur de conmutation
US6194820B1 (en) 1998-02-20 2001-02-27 Shinko Electric Industries Co., Ltd. Discharge tube having switching spark gap
EP1918600A1 (fr) 2006-10-30 2008-05-07 Valeo Embrayages Embrayage pour véhicules automobiles à moyens de centrage du cordon rampe sur le plateau de pression
CN103594304A (zh) * 2013-11-21 2014-02-19 四川天微电子有限责任公司 放电管点火装置
WO2022212376A1 (fr) * 2021-03-29 2022-10-06 The Regents Of The University Of California Revêtement blanc froid pulvérisable à base de microsphères de céramique

Also Published As

Publication number Publication date
JP3749754B2 (ja) 2006-03-01
EP0769832A4 (fr) 1998-07-15
CA2194212A1 (fr) 1996-11-07
KR100206035B1 (ko) 1999-07-01
WO1996035249A1 (fr) 1996-11-07
KR960042810A (ko) 1996-12-21
JPH0922769A (ja) 1997-01-21

Similar Documents

Publication Publication Date Title
US4769736A (en) Gas discharge surge arrester
US4491893A (en) Gas filled surge arrester
JPH0343759B2 (fr)
US5336970A (en) Gas tube protector
US4502087A (en) Surge voltage arrester assembly
US4037266A (en) Voltage surge protector
JP2001516943A (ja) ガス充填形放電路
EP0769832A1 (fr) Tube de decharge a surface de decharge revetue
US6362945B1 (en) Gas-filled surge arrester wIth an activating compound formed of a plurality of components
JPH056797B2 (fr)
US6326724B1 (en) Gas-filled discharge gap assembly
JP3378583B2 (ja) ガス充填形放電ギャップ
EP0060530B1 (fr) Protecteur de circuit électrique
US7795810B2 (en) Gas-filled discharge gap
KR0140089B1 (ko) 광물질 첨가제를 함유하는 가스피뢰기
GB2181887A (en) Electrode of surge arrester
RU2227951C2 (ru) Разрядник
US5473220A (en) Discharge tube
US20010026432A1 (en) Protector device
JP2841336B2 (ja) ギャップ型サージアブソーバ
USH60H (en) Long-life triggered spark gap
GB2046009A (en) Excess voltage arrester
JPH0362487A (ja) 高電圧スイッチ素子用ガス入り放電管
JPS63502232A (ja) 内燃機関の点火プラグの特に予備火花ギヤップとして使用のための火花ギヤップ
GB1564224A (en) Excess voltage arresters

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19970124

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT

A4 Supplementary search report drawn up and despatched

Effective date: 19980528

AK Designated contracting states

Kind code of ref document: A4

Designated state(s): DE FR GB IT

17Q First examination report despatched

Effective date: 19990617

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19991028