US2184709A - Rectifier tube - Google Patents

Rectifier tube Download PDF

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Publication number
US2184709A
US2184709A US185456A US18545638A US2184709A US 2184709 A US2184709 A US 2184709A US 185456 A US185456 A US 185456A US 18545638 A US18545638 A US 18545638A US 2184709 A US2184709 A US 2184709A
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United States
Prior art keywords
tube
tubes
pressure
gas
cathode
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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US185456A
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English (en)
Inventor
Bruijnes Johannes
Duinker Daniel Marie
Mulder Johannes Gijsbe Wilhelm
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
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Publication date
Priority to GB20264/34A priority Critical patent/GB429075A/en
Priority to FR776079D priority patent/FR776079A/fr
Application filed by Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Priority to US185456A priority patent/US2184709A/en
Application granted granted Critical
Publication of US2184709A publication Critical patent/US2184709A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/50—Thermionic-cathode tubes
    • H01J17/58—Thermionic-cathode tubes with more than one cathode or anode

Definitions

  • the present invention which is a division of our copendingr U. S. patent application Ser. No. 738,758, led August 6, 1934, relates to incandescible-cathode, gas-iilled rectifier tubes, and 5 more particularly to tubes for rectiiying alternating current of medium voltages, i. e., voltages having a peak value of about 250 volts to about 1000 volts and higher, and for current of several ampres up to 100 amps. and higher.
  • medium voltages i. e., voltages having a peak value of about 250 volts to about 1000 volts and higher, and for current of several ampres up to 100 amps. and higher.
  • incandescible-cathode gas-iilled rectier tubes have been Widely used for various applications and for various voltages, commercially successful tubes of this type could be made for only two voltage ranges, namely, for low voltages up to about 150 volts, and for high voltages above about 1000 volts, whereas for intermediate voltages no satisfactory tubes of this type could be made.v The reasons therefor will be explained below.
  • the tube must have a satisfactory long life, i. e. of the order of one thousand hours and more; must have a high efliciency, i. e., a low internal voltage-drop as compared to the voltage of the alternating current source to be rectified; .and no back discharge should occur in operation, i. e., the tube must withstand the highest inverse voltage which may occur across its electrodes. during operation.
  • the gaseous filling of such tubes consists solely or mainly of an inert gas, for instance 4of argon, and the pressure of the gas filling can be quite high withback as long as the voltage to be rectiiied has a low value, if the tube is to stand higher voltages the pressure of the gaseous iilling has to be reduced.
  • This in the case of tubes having an inert gas filling, results in an objectionable phenomenon, namely, the gradual disappearance oi the gas iilling which is due to the disintegration of the electrodes, especially of the cathode. This disintegration increases with increasing voltages and decreasing gas pressures, whereby thedisintegrated particles of the electrodes occlude the gas 55 within the tube, and deposit on the walls and Divided and this application January 17, 1938, Serial No. 185,456.
  • mercury vapor has been resorted to as the gaseous filling of the tube, whereby an excess of mercury, in liquid form, is provided in the tube; the liquid mercury serving as a reservoir to replace the mercury which disappears because of its occlusion by the disintegrated particles oi the electrodes.
  • the required pressure of the saturated mercury vapor in the tube is obtained by the proper temperature of the mercury, which in turn, as is in a tube designed for quite high voltages, for instance, for voltages abo-ve 1000 volts, as the internal voltage drop in percentage of the voltage of the alternating current source is not excessive, and also because these tubes are usually designed for small currents, whereby the loss in the tube is not a serious matter.
  • low-pressure mercury vapor provides for too high a voltage drop, and ii the pressure of mercury vapor is increased to about a millimeter or several millimeters, back discharge is likely to occur and at the same time the pressure of mercury at higher pressures is quite sensitive to temperature variations caused, for instance, by changes in arnbient temperature.
  • a rectifier having a gaseous illing consisting solely of mercury vapor at a pressure of the order of several millimeters is likely to be unstable in operation.
  • gasiilled incandescent cathode rectiiier tubes were not commercially available for rectiiying alternating voltages of about 250 volts to about 1000 volts (peak values) except in cases or certain special. applications where the high voltage drop of the tube was of no consequence.
  • the difficulty is further increased if the rcctier is used for the rectification of currents of substantial value, especially in tie case oi the high eflicicncy oxide cathode tubes. lin such case because of the large currents, the anode as unes a comparatively high temperature and part or" the electron-emitting material, for in stance barium oxide, which disintegrated 4from the cathode, deposits on the anodes and causes a marked electron emission of the same to thereby promote back discharge. Even if initially the rcotiiier tubes might operate satisfactorily under such conditions, back discharge will set in after awhile.
  • gas- .illled rectifier tubes having a gaseous lling com- Yising an inert gas, preferably argon or neon at pressure ci' between 0.01 and 0.5 mm. of Hg in case of argon, and from 0.02 to 1 mm. of Hg il@ 4in the case of neon, together with saturated mercury vaporthe pressure of the mercury vapor being preferably the same order of magnitude as the pressure of the inert gas-will retain their initial gas pressure in operation.
  • tubes comprising argon at a pressure of 0.2 to 0.4 or neon at a pressure of 0.3 to 0.8 mm. of Hg, give an all-round satisfactory performance at medium voltages. More particularly the disintegration of the electrodes is prevented, the tubes have a satisfactory life and efficiency and the danger of bach discharge is overcome.
  • the anodes of such tubes are made oi or provided with a surface coating of a material which does not form an amalgam with mercury.
  • the anodes are made of polished graphite, of metal coated with graphite, or a chromium or chromium oxide coating may be used.
  • the supports and lead wires may be air-tightly enclosed with reiractory insulating material, for instance, with steatite.
  • the cathode may also be partly enclosed by a shield to eliminate or at least minimize the deposition on the anode ol disintegrating cathode particles.
  • Figure l is a side view partly in section, of a three-phase rectier tube embodying the invention.
  • Fig. 2 is a section along line 2-2 of Fig. 1.
  • the rectifier tube illustrated in Figures 1. and 2 is designed for the rectification of a three-phase alternating current having an effective phase voltage of 220 volts, and thus a peak voltage somewhat above 300 volts.
  • the illustrated tube is designed for currents ci about 6 amperes and is shown in reduced scale, the length of the conas shown at I3.
  • tainer tube being about
  • the tube comprises a container i of vitreous material. Disposed within the container and slightly below the center thereof, is a filainentary cathode 2, preferably an oxide cathode, provided with a suitable oxide coating of high electron emissive properties such as a barium oxide coating.
  • a filainentary cathode 2 preferably an oxide cathode, provided with a suitable oxide coating of high electron emissive properties such as a barium oxide coating.
  • Cathode 2 is supported by supports' 4 and 3, which are secured, preferably welded to chromeiron discs 5, to the outer face of which discs are welded lead wires fi, the chrome iron discs being air-tightly fused to the glass.
  • Surrounding cathode 2 is an open-ended cylin drical screen whi may be electrically connected to one end oi' the cathode, for instance by a conductor il connecting screen 'l with support 4.
  • the screen has among others the advantage of reducing the danger of disintegrating cathode particles reaching thel anodes and the glass wall of the tube.
  • cathode 2 Arranged above cathode 2 are three anodes 9, Ill and I I of similar construction, each being connected to a conductive rod I2, which may be threaded at its end and screwed into the anode, Anode rod' I2 is surrounded by a suitable insulating tube I4, for instance of steatite, which at its upper end I5 is. sealed to a glass tube I6 which preferably forms an integral extension of the glass wall of container I.
  • Rod I2 has its upper end welded to the inner face of a chrome-iron disc Il, which is fused into container l. Secured to the outer face of chrome-iron disc Il is a terminal connection 29 for the anode II, which is electrically connected thereto through rod I2 and chrome-iron disc Il.
  • the anode is provided on its upper portion with an annular bore I8, which extends inwardly into an annular bore I9 of slightly smaller diameter.
  • the lower end of insulating tube I4 snugly nts into bore IS, whereby rod I2 is protectedly enclosed by the tubes I4 and i6.
  • the annular gap formed around tube I4 at bore I8 offers a narrow high-resistant path between the contacting point of tube I4 with the anode and the discharge space. This provision reduces the danger of a glow-discharge being formed at said point.
  • a cylindrical housing 20 Surrounding anodes 9, I0 and Illis a cylindrical housing 20, which is closed at the top and open at the bottom.
  • the space within housing 20 is subdivided into three parts by three radial and preferably imperforated partition walls 2I (see Fig. 2), each part housing one of the anodes.
  • the wall of housing 20 Opposite the central portions of the anodes the wall of housing 20 is broken away and replaced by metal gauze screens 22, 23 and 24 respectively.
  • Such arrangement permits the discharge to take place between the cathode and the anode not only through the open bottom of housing 20, but also through the gauze 22, 23 and 24, the latter also facilitating the heat dissipation of the anodes.
  • and the non-perforated portions of the housing 20, effectively prevent a discharge between the anodes.
  • a suitable potential may be applied to housing Eil by connecting the same to a suitable potential by means of a wire Ztl hermetically led through the container wall at 2B.
  • a mica disc 2l provided in the upper portion of the tube,-serves to protect the seals from being excessively heated from the discharge space.
  • the anodes have a sectorshaped cross-section so as to more completely fill the space formed within housing 20.
  • the gaseous filling of the tube may consist, for instance of neon at a pressure of 0.5 mm. of Hg; a drop of liquid mercury 28 being provided for the generation of mercury vapor, preferably at a pressure of the same order of magnitude as the neon.
  • the desired mercury vapor pressure is obtained by the mercury assuming in operation the temperature giving this pressure, which as is known, can be obtained by the proper disposition of the liquid mercury with regard to the cathode and the discharge.
  • a rectifier tube for rectifying alternating voltages of a peak value of at least 250 volts comprising, an envelope, an incandescible cathode, a cylindrical-shaped screen of conductive material forming a plurality of cavities having sectorshaped cross sections, an anode within each of said cavities and having a sector-shaped crosssection, said screen separating said anodes from each other and substantially enclosing each anode while allowing access of the main discharge thereto, and a gaseous lling comprising saturated mercury and an inert gas.

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  • Vessels And Coating Films For Discharge Lamps (AREA)
US185456A 1933-08-07 1938-01-17 Rectifier tube Expired - Lifetime US2184709A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB20264/34A GB429075A (en) 1933-08-07 1934-07-10 Improvements in electric discharge tubes
FR776079D FR776079A (fr) 1933-08-07 1934-07-17 Tube redresseur à atmosphère gazeuse
US185456A US2184709A (en) 1933-08-07 1938-01-17 Rectifier tube

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE429075X 1933-08-07
US73875834A 1934-08-06 1934-08-06
US185456A US2184709A (en) 1933-08-07 1938-01-17 Rectifier tube

Publications (1)

Publication Number Publication Date
US2184709A true US2184709A (en) 1939-12-26

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Application Number Title Priority Date Filing Date
US185456A Expired - Lifetime US2184709A (en) 1933-08-07 1938-01-17 Rectifier tube

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US (1) US2184709A (fr)
FR (1) FR776079A (fr)
GB (1) GB429075A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2835842A (en) * 1951-04-13 1958-05-20 Philips Corp Electric discharge tube
CN106128919A (zh) * 2016-08-26 2016-11-16 安徽华夏显示技术股份有限公司 一种用于整流管的阳极组件

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2835842A (en) * 1951-04-13 1958-05-20 Philips Corp Electric discharge tube
CN106128919A (zh) * 2016-08-26 2016-11-16 安徽华夏显示技术股份有限公司 一种用于整流管的阳极组件
CN106128919B (zh) * 2016-08-26 2017-10-10 安徽华夏显示技术股份有限公司 一种用于整流管的阳极组件

Also Published As

Publication number Publication date
FR776079A (fr) 1935-01-16
GB429075A (en) 1935-05-23

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