US2450770A - High-voltage rectifying tube - Google Patents
High-voltage rectifying tube Download PDFInfo
- Publication number
- US2450770A US2450770A US721647A US72164747A US2450770A US 2450770 A US2450770 A US 2450770A US 721647 A US721647 A US 721647A US 72164747 A US72164747 A US 72164747A US 2450770 A US2450770 A US 2450770A
- Authority
- US
- United States
- Prior art keywords
- cathode
- rectifying tube
- tube
- voltage rectifying
- anode
- 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
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J17/00—Gas-filled discharge tubes with solid cathode
- H01J17/02—Details
- H01J17/04—Electrodes; Screens
- H01J17/06—Cathodes
Definitions
- This invention relates to a rectifier tube comprising a filament cathode and a metal vapour filling for use at high voltages that is to say exceeding 500 volts.
- the cathode In the known tubes of the aforesaid type the cathode is generally coated with barium oxide or with an oxide of other alkaline earth metal in order to ensure a high emission of electrons.
- These tubes have a limitation in that notwithstanding all kinds of screening measures, the cathode, due to the bombardment by ions, has a life of not more than some few thousands of hours. If the anode voltage exceeds some few thousands of volts, backfiring frequently occurs because the anode starts to emit at those points at which small quantities of barium which have left the cathode by volatilisation are deposited.
- Non-carbonised tungsten-thorium cathodes have also for a long time been known, used with rare gases as well as with a metal vapour-filling, butthe life of such cathodes is short.
- a rectifying tube according to the invention is provided with a carbonised tungsten-thorium cathode, the tube being filled with metal vapour.
- tubes according to the invention have a long life and that there is no probability at all of backfiring due to the presence of active cathode material on the anode. Due to the cathode being surrounded with screens, the required filament current energy does not exceed twice the energy required for a cathode activated with alkaline earth metal oxides.
- I designates the glass wall of a tube comprising an anode 2, an intermediate electrode 3 and a cathode sleeve 4.
- the cathode sleeve contains a helical cathode 5.
- This cathode is made of tungsten having added to it 2% of thoria.
- This filament wire is carbonised by heating in acetylene at a pressure of about 1 mm. for a time such that about 30% of the cross sectional area of the wire is carbonised.
- the tube is intended for use at a voltage, to be rectified, of 5 kilovolts; it has a life of many thousands of hours.
- a drop of mercury 6 at the bottom of the tube ensures the presence of a sufiicient quantity of mercuryvapour.
- a high-voltage rectifying tube comprising a sealed envelope containin an anode, and a cathode which is constituted by a carbonised tungsten-thorium wire and an atmosphere of a metal vapor.
- a high-voltage rectifying tube comprising a sealed envelope containing an atmosphere of mercury vapour, and a cathode of tungsten-thorium wire carbonized to an extent within about 30% of its cross-sectional area.
- a high-voltage, rectifying tube comprising a sealed envelope containing an atmosphere of mercury vapour, an anode, a cathode of tungstenthorium wire carbonized to an extent within about 30% of its cross-sectional area, and a semienclosure for the cathode within the direct path between the cathode and the anode.
Landscapes
- Physical Or Chemical Processes And Apparatus (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL2450770X | 1945-11-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2450770A true US2450770A (en) | 1948-10-05 |
Family
ID=19874252
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US721647A Expired - Lifetime US2450770A (en) | 1945-11-14 | 1947-01-11 | High-voltage rectifying tube |
Country Status (2)
Country | Link |
---|---|
US (1) | US2450770A (fr) |
FR (1) | FR935845A (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2693546A (en) * | 1948-07-10 | 1954-11-02 | Eitel Mccullough Inc | Electron emitter for electron tubes |
US2879432A (en) * | 1956-03-16 | 1959-03-24 | Gen Electric | Electron emitter |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2088249A (en) * | 1931-08-04 | 1937-07-27 | Raytheon Mfg Co | Gaseous rectifier |
-
1946
- 1946-11-12 FR FR935845D patent/FR935845A/fr not_active Expired
-
1947
- 1947-01-11 US US721647A patent/US2450770A/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2088249A (en) * | 1931-08-04 | 1937-07-27 | Raytheon Mfg Co | Gaseous rectifier |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2693546A (en) * | 1948-07-10 | 1954-11-02 | Eitel Mccullough Inc | Electron emitter for electron tubes |
US2879432A (en) * | 1956-03-16 | 1959-03-24 | Gen Electric | Electron emitter |
Also Published As
Publication number | Publication date |
---|---|
FR935845A (fr) | 1948-07-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
GB648955A (en) | Improvements in electron-emitting electrodes for electric discharge tubes | |
US2518879A (en) | Hydrogen thyratron | |
US2677071A (en) | Voltage reference tube | |
US1874753A (en) | Controlled arc discharge apparatus | |
US2450770A (en) | High-voltage rectifying tube | |
US2488716A (en) | Electric high-pressure discharge tube | |
US1897471A (en) | Regulator | |
US2591474A (en) | Cold cathode discharge device | |
US2122932A (en) | Gaseous discharge tube | |
US2034571A (en) | Electrical discharge device and method of operating same | |
US2353635A (en) | Cathode for discharge tubes | |
US3461335A (en) | Glow-discharge tubes containing a radio-active primer | |
US1790153A (en) | Electrical discharge device and method of operation | |
US2927240A (en) | Gaseous discharge device | |
US2961566A (en) | Fluorescent lamp | |
US2121591A (en) | Grid glow tube with zero temperature effect | |
US2740914A (en) | Thermionic cathodes | |
US1648458A (en) | Electron-discharge device and method of operating the same | |
US2864024A (en) | Glow-discharge tube | |
US3439209A (en) | Positive column gas discharge lamp employing an alloy of two metals with impedance-free terminal connections | |
US2053501A (en) | Thermionic gaseous discharge rectifier | |
US2236289A (en) | Thermionic device | |
US2046941A (en) | Gaseous electric discharge device | |
US2106855A (en) | Space-current device | |
GB937391A (en) | Cold-cathode glow-discharge tubes |