US2030434A - Gaseous electric discharge device - Google Patents

Description

Feb. 11, 1936. E. G. DoRGl-:Lo

GASEOUS ELECTRIC DISCHARGE DEVICE Filed April 16, 1935 INVENTOR Mun/WZ Patented Fete@ M9 EQ@ narran stares access@ desirous penetrare meenemen nutren Eduard Gi., Bargeld, Eindhoven, Netherlands, signor to General Eimtnc Company, a corpo@ ration of New York Application Aprill 11.6, i935, Seriali Nit. llttd? lin the Netherlands Aprill i9, 193@ 2 Cia-sims.

"idle present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to starting and operating circuits for such devices.

5, I have observed that in illuminating systems comprising a plurality of transformers having the primaries thereof connected in series across the terminals of an alternating current source and the secondaries thereof connected to a gaseous l@ electric discharge lamp device of the type having thermionic electrodes and operating with an elevated container temperature, such as sodium vapor lamps, the number of lamp's which can be successfully started and operated on the voltage yg of the current source is limited. When the number of lamps is too large the thermionic electrodes thereof arenot heated at all or are heated very slowly tothe temperature most favorable for theecient operation of the lamp. The lamps thus require an appreciable time to attain the temperature at which they operate at maximum efficiency and perhaps do not reach such tempera- ,ture at all.

The object of the present invention is to increase the number of gaseous electric discharge vapor lamps which can be successfully started and operated in circuits of the above type. A further object of the invention is to shorten the starting period of such lamps in such; circuits. Still fur- 3o ther objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

The invention attains its objects by connecting 3d a choke coil in parallel with a number of transformer primaries and in series with the other transformer primaries in the circuit. When potential is applied'to the above described circuit a higher current flows through the transformer pri- '40 maries connected in series with the choke coil than would ow therethrough'in the absence" of said .choke coil. When the electrodes are of the type having a heater foi` the electron emitting material, which heater is connected across a few 45 turns of the transformer secondary, the higher transformer current rapidly heats the electrodes to the electron emitting, discharge supporting temperature thereof and the lamp container is rapidly raised to the elevated temperature at 50 which the lamp operates eciently. When the electrodes are of the type wherein the electron emitting material is heated directlyl by the discharge incident thereat and the discharge current flow therethrough the higher transformer -55 current causes a higher discharge current between the electrodes, which are cold when the circuit is closed, andthe electrodes are rapidly heated to the electron emitting, discharge supporting teinperature thereof and the lamp container is rapidly raised to the velevated temperatures at which the 5 lamp operates emciently. `when the operating current is nowing through these lamps the potential difference between the ends or" the chokecoil is such that current ow through the 4primaries of the transformers connected in parallel w with said choke-coil is sucient to rapidly heat the thermionic electrodes of the lamps connected to the secondaries of said transformers and the containers of the lamps to the temperature at which said lamps operate efficiently. 5

In the drawing accompanying and forming part of this specication'an embodiment of the invention is shown schematically.

Referring to the drawing the new and, novel illuminating system comprises a plurality of 2@ gaseous electric discharge lamp devices i and 2 eachV of which comprises an elongated container having a pair of electrodes tl sealed therein and mounted at opposite ends thereof and a gaseous atmosphere therein, such as neon and sodium va- 25 por. A quantity of sodium is introduced into the container of the lamp during the manufacture thereof and is the source of the sodium vapor. Said electrodes 3 are electron emitting when heated and each of said electrodes 3 comprises a 30 heater lament, such as a tungsten or a nickel filament, coated or impregnated with an electron emitting material, such as barium and barium oxide. When desired the heater filament is wrapped around a bar or rod of electron emitting material. For purposes of simplicity or" illustration the lamps i and 2 are shown schematically in the drawing. Since the structure of this type of lamp is now Well known further description and illustration thereof has been omitted.

Each of the discharge vlamps i connected to the secondary d of a transformer 3, 6 and each of the lamps 2 is connected to the secondary 5 of a transformer 5, l. The primaries 6 and l of said transformers 4, 6 and 5, l are connected in series 45 across the terminals B of an alternating current source. The heating current for each of said electrodes 3 is supplied by a few turns at the end of the secondary 4 or 5 of said transformers 4, 6 or 5, l, respectively. The alternating `current; source for the above described circuit is, preferably, a constant current transformer. A choke coil 9 is connected in parallel to the primaries lV and in series with the primaries 6 with respect to the current source 8.

charge supporting temperature and the dis-` charge in the gas betweenthe electrodes 3 in each of said lamps I starts shortly after potential is applied to the circuit. The lamp container is rapidly heated by said gas discharge to the vaporization temperature of the sodium and the lamp is an eicient source of sodium vapor light.

When the operating discharge current is flowing in the lamps I the potential difference between the ends of the choke coil 9 is considerably greater than during the starting period of said lamps I. The size of the choke coil 9 with relation to the number of lamps 2 is such that the potential difference between the ends of the choke coil 8 after the lamps I have started is suilicient to start the lamps 2 into operation.

When all the lamps I and 2 have been started into operation the current ow through the tubes 2 is slightly lower than the current flow through the lamps I, due to the choke coil 9. However, since the current through said choke-coil 9 lags about with respect to the current iiow through the lamps 2, the difference between the lamp 2 current and the lamp I current is so small as to be insignicant and it is not necessary to disconnect the choke-coil 8 after the lamps have been started into operation.

. When desired, the electrodes 3 are of the type which are heated to and maintained at an electron emitting, discharge supporting temperature by the discharge current. In this case the high current flowing through the seoondaries 5 causes a more intense glow-discharge current between the electrodes 3 which rapidly brings the lamps 2 to their elevated operating temperature.

While I have shown and described and have pointed out in the annexed claims certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of tle device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention, for example, the transformers 4, 6 and 5, 1 are autotransformers, when desired, and the gaseous atmosphere of the lamps consists of or comprises other metal vapors, such as mercury vapor,cad mium vapor, magnesium vapor, or thallium vapor.

What I claim as new and desire to secure by Letters Patent of the United States, is:-

l. An illuminating system comprising in combination a current source, a plurality of gaseous electric discharge lamps, a plurality of transformers therefor, the primaries of said transformers being connected in series across the terminals of said current source and a choke coil connected in series with some of said transformer primaries and in parallel with the others of said transformer primaries with respect to said current source, said choke-coil starting said lamps connected to the transformers connected in parallel thereto after said lamps connected to said transformers connected in series therewith have started.

2. An illumina-ting system comprising in combination a constant current source, a plurality of gaseous electric discharge lamps, a plurality of transformers therefor, the primaries of said transformers being connected in series across the terminals of said current source and a choke coil connected in series with some of said transformer primaries and in parallel with the others of said transformer primaries with respect to said current source, said choke-coil starting said lamps connected to the transformers connected in parallel thereto after said lamps connected to said transformers connected in series therewith have started.

EDUARD G. DORGELO.

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