US2056628A - Self starting gaseous electric discharge device - Google Patents

Self starting gaseous electric discharge device Download PDF

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Publication number
US2056628A
US2056628A US699264A US69926433A US2056628A US 2056628 A US2056628 A US 2056628A US 699264 A US699264 A US 699264A US 69926433 A US69926433 A US 69926433A US 2056628 A US2056628 A US 2056628A
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United States
Prior art keywords
envelope
electrode
lamp
temperature
discharge device
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.)
Expired - Lifetime
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US699264A
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English (en)
Inventor
Louis James A St
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.)
General Electric Vapor Lamp Co
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General Electric Vapor Lamp Co
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
Priority to BE406408D priority Critical patent/BE406408A/xx
Application filed by General Electric Vapor Lamp Co filed Critical General Electric Vapor Lamp Co
Priority to US699264A priority patent/US2056628A/en
Priority to DEP69687D priority patent/DE643861C/de
Priority to FR781585D priority patent/FR781585A/fr
Priority to GB33619/34A priority patent/GB447617A/en
Application granted granted Critical
Publication of US2056628A publication Critical patent/US2056628A/en
Anticipated expiration legal-status Critical
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/82—Lamps with high-pressure unconstricted discharge having a cold pressure > 400 Torr
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/067—Main electrodes for low-pressure discharge lamps
    • H01J61/0672—Main electrodes for low-pressure discharge lamps characterised by the construction of the electrode

Definitions

  • the present invention relates to gaseous electric discharge devices in general, and in particular to metallic vapor devices.
  • a particular object of the invention is to provide a high efilciency light source. Another object of the invention is to provide a metallic vapor arc which is exceptionally stable in operation. Another object of my invention is to provide a metallic vapor arc device which will operate at a relatively high pressure. Another object of my invention is to provide a metallic vapor discharge device whose electrical characteristics will remain constant throughout an appreciable range of vapor temperature. Another object of my invention is to provide a gaseous discharge device which will start without the use of high voltage or auxiliary apparatus. A further object of my invention is to provide an electrode for a gaseous discharge device which is simple in construction and which will have a long useful life. Still other objects and advantages of my invention will appear from the following detailed specification, or from an inspection of the accompanying drawing.
  • the entire envelope may be made to operate at a much more uniform temperature, with the result that any of the harder glasses, such as pyrex, nonex, or the like, may be ernployed for the first time for the envelope et a lamp operating with a minimum temperature at the coolest point which is well above 357 C.
  • One of these changes which I have found to be necessary is the relocation of the electrodes at a point extremely close to the ends of the envelope. which are made hemispherical, so that the zone baci: of the electrodes, which is the coolest part of the envelope, may be heated by the electrodes.
  • This new cathode of my invention is so formed as to have an extremely small heat radiating surface in proportion to the electron emitting surface, a relatively low thermal capacity, and poor heat conduction from one part thereof to another.
  • a cathode having all of these novel characteristics can be conveniently produced by folding or rolling a piece of metal gauze into a compact mass, although any other metallic body having a similar maze of internal passages may also be used.
  • Exceptionally good results have been obtained using a cylindrical electrode of tightly rolled metal gauze having a small central opening.
  • the total surface of such an electrode may be easily made of the order of ten times the exterior, heat radiating, surface thereof, with the result that the heat loss from such an electrode per unit of active surface is extremely low. Hence little heat is needed to keep my novel electrode at an elevated temperature.
  • the thermal capacity of this novel electrode is likewise extremely low, as is also the heat conductivity thereof, due to the cellular structure.
  • my novel cathode has an open bore of the order of 2 mm. in diameter.
  • This open bore greatly facilitates the coating of the interior portion of the electrode, and likewise makes it possible to easily raise the temperature of the electrode by induction sufficiently to thoroughly degas it and to break down the alkaline compounds used in the coatings. In addition to this, however, this open bore tends to attract the discharge at certain gas pressures, and thus to provide the beneficial effects of a cavity.
  • Fig. 1 is a perspective View of a mercury vapor lamp.
  • Fig. 2 is a sectional elevation of the arc tube employed in this lamp
  • Fig. 3 is an elevational view, in part section, of a modification of the lamp of Fig. 1
  • Fig. 4 is a perspective view of the electrode material before it is rolled up
  • Fig. 5l is an end view of an electrode, greatly enlarged.
  • a preferred form of my mercury vapor arc lamp has a sealed tubular envelope I of any suitable vitreous material, such as glass.
  • This envelope may be either transparent or translucent, as desired.
  • this envelope is conveniently made two inches in diameter and eleven inches long.
  • a pair of inleads 2 and 3 extend through a re-entrant pinch seal at one end of said envelope, said inleads being connected to the tip and sleeve, respectively, of a conventional mogul base 4.
  • a supportwire 5 is likewise fused into said pinch symmetrically with the inlead 3.
  • Said inlead 3 and support wire 5 are each bent outwardly and carry at their outer ends the wires 6 and l, respectively, which are of tungsten or any other material having the necessary rigidity.
  • Said wires 6 and l extend parallel to the axis of the envelope l to a point near the opposite end thereof.
  • Said wires 6 and l pass through two spaced metal -rings 8 and 9 which are suitably affixed thereto, as by welding or the like.
  • a sealed tubular envelope lil of suitable heat resisting vitreous material, such as pyrex, nonex, fused silica or the like, has hemispherical ends which rest in said rings, whereby it is supported in a nxed position Within the envelope l.
  • this envelope is about 7 inches long and 13% inches in diameter.
  • the walls of this envelope are preferably of the order of a millimeter thick, so that it has little heat capacity and thus warms up quickly, without danger of strains.
  • the ring ii has a mica ring ll affixed thereto which snugly nts the inside of the envelope i, whereby lateral support is provided for the free ends of the wires 6 and i.
  • Said envelope lil has an inlead i2, which is conveniently made of tungsten, sealed into each end thereof, each of said inleads terminating just inside of said envelope.
  • a wire i3 of tungsten, molybdenum, or other metal of suicient rigidity, a 25 mil molybdenum wire being entirely satisfactory, is attached to the inner end of each of said inleads l2, each wire i3 being formed into a transverse loop of appreciable diameter and supporting at its free end an electrode iii, these electrodes being about 6 inches apart in a 490 watt lamp.
  • the upper inlead l2 is joined .to the inlead 2 by a flexible lead i8 which is conveniently formed of stranded soft nickel wire, while the lower inlead l2 is similarly connected by a soft stranded wire i9 to the support wire 6.
  • Several turns of wire l5 are closely wrapped about the envelope ll@ at a point about a third of the way from the upper electrode l l toward the lower electrode, this wire being electrically connected to the wire t, and thus to said lower electrode.
  • the bottom of said envelope lil about said electrode has a heat intercepting gold lm l5 thereon, which may conveniently beapplied in the form oi a lacquer.
  • rii'he inner envelope itl has a filling of a rare gas, such as argon at a pressure of the order of 5 mm. of mercury, which constitutes the ionizable medium when the lamp is first started.
  • a rare gas such as argon
  • An accurately measured quantity of the vaporizable metal such as mercury, sodium, thallium, cadmium, or the like, is likewise sealed within this envelope. The amount of this metal is so chosen that it will all be evaporated when the coolest part of the envelope is at a desired temperature.
  • a mercury vapor lamp it has been found that a vapor density corresponding to a temperature of the order of 360 C. is especially desirable for many purposes, hence the mercury is preferably so limited as to be completely vaporized when the coolest part of the envelope is at this temperature.
  • the'outer envelope l would be evacuated in order to minimize the heat conduction from the inner envelope l0, but in practice it is found to be impracticable to entirely degas the various metal parts therein, with the result that residual gas evolves during operation of the lamp and supports an undesired glow discharge between the inleads 2 and 3. Accordingly, I prefer to ll the envelope l with a gas, such as nitrogen, at a pressure which issuiiicient to prevent the production of a glow discharge between these inleads. 'I'hus in a 220 volt lamp I vpreferably use nitrogen at a pressure of approximately half an atmosphere.
  • a gas such as nitrogen
  • the electrodes I4 are especially designed to minimize the sputtering thereof, both during starting and during operation. As particularly shown in Rigs. 4 and 5 these electrodes are preferably formed of metal gauze which is rolled up to form a cylindrical electrode having an open bore. AThis electrode can be made of nickel, tungsten, molybdenum or the like, but in practice I have obtained extremely good results and long life using a gauze of seven mil nickel wire having 60 wires per inch parallel to the axis of the elec- ⁇ trode and 40 in the other direction.
  • the electrode likewise has an electron emitting surface of approximately 2.6 sq. inches, although its effective heat radiatingsurface is only of the order of .3 sq. inch.
  • the central opening in the electrode likewise greatly facilitates this penetration.
  • the electrodes After the electrodes have been suitably dried they are sealed into the envelope ill in an obvious manner. Since electrodes so coated do not undergo any chemical change in air they may be stored as long as desired without any special precautions, such as have necessarily been observed with the electrodes of the prior art.
  • the envelope lil is then exhausted and thoroughly baked to drive out any occluded gas, after which the electrodes lt are heated by induction to a temperature suflicient to break down the carbonates to the oxide, the evolved gas being evacuated as produced.
  • the loops I3 restrict heat ow from the electrodes l during this heating, of course, and thus both protect the seals, and make it easier to produce the necessary electrode temperature.
  • a carefully measured quantity of mercury 150 mg. in the case which has been described, is lintroduced within the envelope i0, together with a rare gas, argon at a pressure of the order of 5 mm. of mercury being preferred.
  • the envelope I is then sealed off, after which it is placed in the envelope I in the manner which has been shown and described.
  • My novel device when constructed as described, will start when an alternating current potential of 150 volts is applied thereto. This relatively low breakdown potential is the result of several factors.
  • the wireG due to its proximity to the envelope I0, is eifective to some extent to reduceA the potential necessary to start the discharge, due to the fact that it is connected to one of the electrodes I4.
  • the presence of the encompassing wire I5 greatly increases this effect if this wire is located at a critical point which is approximately two-thirds of the distance from the electrode Il to which it is connected toward the other electrode, although this wire I will be cf value if located anywhere between a quarter and a half of the way toward the electrode to which it is connected.
  • a single turn of said wire I5 at the exact critical point would be suiiicient to produce the major part of this reduction in breakdown voltage, but by providing several turns thereof the effect is slightly enhanced, and at the same time the exact position of the edges thereof becomes less critical, so that the device may be more readily produced by mass production methods.
  • the numerous points on the electrodes I4 are likewise believed to concentrate the static field, since they facilitate the necessary ionization of the gas, with a consequent further reduction in the breakdown potential of the device.
  • the active coating on these electrodes likewise enhances this result.
  • my novel lamp has a negativevolt ampere characteristic.
  • myflamp is ordinarily operated in seriesiwith a ⁇ suitable inductance on 220 volts A. C.
  • This inductance causes the lamp current to lag behind the line voltage and thus continues the light on one half cycle until a favorable moment for the initiation of a reverse discharge on the next half cycle.
  • the usual flicker observable with alternating current discharge lamps is virtually eliminated, due to the unusually short dark interval.
  • the iron of the'finductance should not be saturated by the maximum current drawn, a reactor having an air gap being preferred, since a saturable reactor tends both to peak the current, causing a noticeable flicker, and to so limit the current at the beginning of the cycle as to render the arc unstable.
  • my novel device will operate with an arc voltage of the order of 160 volts with a current of 2.8 amperes, regardless of reasonable variations in ambient temperature.
  • my novel lamp is especially suitable for street and other outdoor lighting, where the extreme variations in temperature have made it impracticable to operate a mercury vapor arc heretofore.
  • my novel lamp is combined in a single fixture with incandescent lamps, for the heat of the incandescent lamps will have virtually no effect upon the operation of the vapor arc.
  • my novel lamp has a. total output of approximately 14,000 lumens, this being about 35 lumens per watt.
  • the outer envelope By making the lamp smaller in diameter and operating with the same arc current andl voltage the outer envelope may be eliminated, but in this case it is usually necessary to make the envelope of fused silica, fused iluorite, or one of the harder glasses, intermediate between pyrex and fused silica, in order to withstand the higher temperatures which must be developed to insure freedom from mercury condensation due to drafts or the like.
  • the ultraviolet emission of such a lamp is often desirable, however, and hence such a construction, using fused silica, iluorite, or the like, is preferred in some cases.
  • Such a lamp retains all the advantages of self-starting and stable and high efciency operation which have been heretofore described.
  • FIG. 3 A construction which has been found to give good results .in this type of lamp is shown in Fig. 3.
  • is made of fused silica tubing having an inside diameter of approximately of an inch.
  • the electrodes I4, which are approximately 6 inches apart, are supported by the in-l leads
  • Said inleads are each sealed into said envelope 2
  • An asbestos tube 23 is placed about each of said seals in order to maintain the temperature thereof, and in addition a heater 24 is preferably Acoiled thereabout.
  • Said heater conveniently comprises about 10 or 12 turns of #21 nichrome wire, or enough of any other resistance wire to give approximately 1 ohm resistance.
  • One end of said heater 24 is connected to the adjacent inlead l2, while the other end thereof is connected to a combined terminal and guard 25 which is attached to the end of said envelope 2
  • An annular baille 26 is fused to the wall of said envelope 2
  • a wire 2l is wound about the arc tube 2
  • Said envelope 2i is filled with argon at a pressure of the order of mm. of mercury and contains a quantity of mercury,- about 35 mg., which will all be vaporized at the same temperature as that in the lamp of Fig. l
  • the lamp of Fig. 3 will start and operate, in series with a stabilizing inductance, on 220 volts A. C. with substantially the same characteristics as the lamp of Fig. l, the baille 26 causing but little change in either the starting or operating potential.
  • the absence of the outer envelope is, of course, compensated for by the smaller heat radiating surface, this lamp operating at a temperature considerably in excess of that of Fig. l
  • each graded seal 22 vcause each graded seal 22 to be maintained at the requisite temperature to prevent mercury con densation therein, despite the distance thereof from the discharge, while the baille 2t breaks up the convection currents and thus causes a greater proportion of heat to be retained about the lower electrode lil, so that it will operate at substantially the same temperature as the upper electrode id. ln addition said shield 2B reduces the blackening of the arc tube by particles sputtered from the lower electrode.
  • This lamp has been found to be an extremely eihcient ultraviolet generator, and is useful for various therapeutic and photo-chemical purposes.
  • An electric gaseous discharge device comprising a sealed tubular envelope of vitreous material, an electrode sealed into each end thereof, a vaporizable material within said envelope in an amount which is less than that necessary to saturate the space within said envelope at the normal operating temperature of said device, a heat trap adjacent the lower end only of said envelope to reduce the heat losses therefrom to overcome the unequal cooling effect of convection currents on opposite ends of said device, and electrical connections for supplying suillcient energy to said device to raise it to said temperature.
  • An electric gaseous discharge device comprising a sealed tubular envelope of vitreous material, an electrode sealed into each end thereof, a vaporizable material within said envelope in an amount which is less than that necessary to saturate the space within said envelope at the normal operating temperature of said device, an
  • annular baffle within said envelope close to the lower electrode to increase the amount of heat retained at the lower end of said envelope, and electrical connections for supplying sufiicient energy to said device to raise it to said temperature.
  • An electric gaseous discharge device comprising a sealed tubular envelope of ⁇ vitreous material, an inlead sealed into each end thereof, an electrode consisting of a plurality of contiguous layers of metal gauze almost in contact with each end of said envelope, said gauze being coated throughout with an alkaline oxide, a connection between each inlead and the adjacent electrode which is longer than the distance therebetween whereby heat conduction to said inleads is minirnized, a vaporizable material within said envelope and a conducting band having at least one complete turn about said envelope at a point which is substantially a third of the way from one electrode toward the other, said band being electrically connected to the latter electrode.
  • An electric gaseous discharge device comprising a sealed tubular envelope of vitreous material, an inlead sealed into each end thereof, an
  • said electrode almost in contact with each end of said envelope, said electrode being coated with an alkaline oxide', a connection between each inlead and the adjacent electrode which is longer than the distance therebetween whereby heat conduction to said inleads is minimized, a vaporizable material within said envelope, a conducting band having at least one complete turn about said envelope at a point which is substantially a third of the way from one electrode toward the other, said band being electrically connected to the latter electrode, and a heat intercepting coating on one end only of said envelope about the inlead.
  • An electric gaseous discharge device comprising a sealed tubular envelope of vitreous inaterial, an inlead sealed into each end thereof, an electrode almost in contact with each end of said envelope, said electrode being coated with an alkaline oxide, a connection between each inlead and the adjacent electrode which is longer than .the distance therebetween whereby heat conduction to said inleads is minimized, a vaporizable material within said envelope, a conducting band having at least one complete turn about said envelope at a point which is substantially a third of the way from one electrode toward the other, said band being electrically connected to the latter electrode, and an electrical resistance heater about the inlead seals to prevent vapor condensation therein.
  • a gaseous electric discharge device comprising a tubular sealed envelope, a gaseous atmosphere therein, electrodes sealed into said envelope at opposite ends thereof, and an electrically conductive band having at least one complete turn about said envelope at a point substantially one third of the distance ⁇ from one electrode toward another, said band being electrically connected with the more remote of said electrodes.
  • An electric gaseous discharge device comprising a tubular sealed envelope, a gaseous atmosphere therein, electrodes sealed into said en, velope at opposite yends thereof, an electrical conductor extending along the surface of said envelope from a point adjacent to one of said electrodes to a point two,.thirds of the distance toward the other of said electrodes, said conductor being connected to the first of said electrodes. the free end of said conductor terminating in a conductive band which encompasses said envelope.
  • a cathode consisting of a metal body having a maze of internal passages whereby the total surface of said body is several fold the exterior heat radiating surface thereof, the entire surface of said body including that of the internal passages being coated with a substance having a high thermionic emission which is thin enough to not close said passages.
  • a cathode consisting of a body of metal gauze having a plurality of contiguous layers of said gauze, the total surface of said gauze being at least several fold the exterior heat radiating surface of said body, the wires forming said gauze being coated throughout said body with a substance having a high thermionic emission which does not vclose the interstices within said body.
  • a cathode consisting of a body of metal gauze having a plurality of contiguous layers of said gauze, the wires forming said gauze being coated throughout said body with an alkaline earth oxide, the cut ends of said wires being exposed on at least one surfaceof said body.
  • a cathode consisting of a roll of metal lgauze having a plurality of contiguous turns and an open bore of the order of two millimeters in diameter, the wires forming said gauze being coated throughout said roll with an alkaline earth oxide, the cut ends of said wires being exposed at the end of said roll.
  • a cathod consisting of a body of metal gauze having a plurality ⁇ of contiguous layers of said gauze, part of the ⁇ wires forming said gauze consisting of nickel while the remainder consists of a more refractory metal, the cut ends of the latter wires being exposed on at least one surface of said body, said wires being coated throughout with an alkaline earth oxide.
  • a cathode consisting of a roll of metal gauze having a plun rality of contiguous turns, the wires of said gauze which extend around the axis of said roll consisting of nickel while the wires parallel to said axis consist of a more refractory metal, the cut ends of the latter wires being exposed at one end of said roll, all of said wires being coated throughout said roll with a substance having a high thermionic emission.

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  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Discharge Lamp (AREA)
US699264A 1933-11-22 1933-11-22 Self starting gaseous electric discharge device Expired - Lifetime US2056628A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE406408D BE406408A (tr) 1933-11-22
US699264A US2056628A (en) 1933-11-22 1933-11-22 Self starting gaseous electric discharge device
DEP69687D DE643861C (de) 1933-11-22 1934-07-11 Elektrische Metalldampfleuchtroehre mit Gluehelektroden
FR781585D FR781585A (fr) 1933-11-22 1934-11-20 Tube à décharge à amorçage automatique
GB33619/34A GB447617A (en) 1933-11-22 1934-11-22 Improvements in or relating to gaseous electric discharge devices

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US699264A US2056628A (en) 1933-11-22 1933-11-22 Self starting gaseous electric discharge device

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US2056628A true US2056628A (en) 1936-10-06

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US699264A Expired - Lifetime US2056628A (en) 1933-11-22 1933-11-22 Self starting gaseous electric discharge device

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US (1) US2056628A (tr)
BE (1) BE406408A (tr)
DE (1) DE643861C (tr)
FR (1) FR781585A (tr)
GB (1) GB447617A (tr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4629929A (en) * 1982-02-10 1986-12-16 Mitsubishi Denki Kabushiki Kaisha Metal vapor discharge lamp
US20080038950A1 (en) * 2006-08-11 2008-02-14 Haro Robert C Lamp fasteners for semiconductor processing reactors

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109805000B (zh) * 2019-03-29 2024-04-16 福建锦特新材料科技有限公司 一种带电防护网与其生产方法及应用其的帐篷

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4629929A (en) * 1982-02-10 1986-12-16 Mitsubishi Denki Kabushiki Kaisha Metal vapor discharge lamp
US20080038950A1 (en) * 2006-08-11 2008-02-14 Haro Robert C Lamp fasteners for semiconductor processing reactors
US7597574B2 (en) * 2006-08-11 2009-10-06 Asm America, Inc. Lamp fasteners for semiconductor processing reactors

Also Published As

Publication number Publication date
FR781585A (fr) 1935-05-18
BE406408A (tr)
GB447617A (en) 1936-05-22
DE643861C (de) 1937-04-19

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