US2030426A - Gaseous electric discharge lamp device - Google Patents

Description

Feb. '11, 1936. BLOK 2,030,426

GASEOUS ELECTRI'C DISCHARGE LAMP DEVICE Filed June 2, 1954 INVENTOR RNEY Patented Feb. 11, 1936 UNITED STATES,

PATENT OFFICE GASEOUS ELECTRIC DISCHARGE LAMP DEVICE New York Application June 2. 1934, Serial No. 728,765 In the Netherlands June 24, 1933 x 2 Claims.

The present invention relates to gaseous electric discharge lamp devices generally and more particularly the invention relates to methods and means for startingand operating such devices.

The starting of gaseous electric discharge devices is facilitated by connecting a condenser in parallel with said device and a self-inductance in series with said device. After the device has been started into operation the condenser is no longer necessary and it is desirable to disconnect the condenser since it shortens the operating life of the device when left in the circuit. The object of the present invention is to provide an automatic, simple and positive acting'means to cut out of circuit the condenser after the gaseous electric discharge device has been started into operation. Still further 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.

.In accordance with this object the invention comprises an auxiliary gaseous electric discharge device having cold electrodes connected in series with the condenser. The operating voltage of the auxiliary gaseous electric discharge device is higher than the voltage across the electrodes thereof after the main device has been started into operation. The starting voltage of the auxil iary discharge device is such that the voltage across the electrodes thereof during the starting period of the main discharge device is sufficient to initiate a discharge therein and the auxiliary discharge device permits current to flow to the condenser. A high voltage builds up at the condenser which discharges through the main discharge device to start the latter into operation. After the main device has been started into operation the voltage across the electrodes of the auxiliary device drops below the operating voltage of the auxiliary device which stops operating to interrupt the flow of current to the condenser. The condenser is thus cut out of circuit by a simple, automatic positive acting means and the operating life of the main discharge device is increased.

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

Referring to the drawing the new and novel circuit comprises a gaseous electric discharge lamp device I of the positive column type having an elongated tubular container of approximately 25 cms. in length with electrodes 2 and 3 sealed into opposite ends of said container. Said electrodes 2 and 3 are electron emitting when heated and consist of a coiled metal filament, such as a tungsten or a nickel filament, coated or impregnated with an electron emitting material. such as barium oxide. Said device I has a gaseous atmosphere therein such as neon. The dis- 5 charge voltage of the lamp device I is approximately 500 volts. It will be understood, of course, that the gaseous filling of said device may consist of a mixture of gases, a mixture of gas and metal vapor, such as a mixture of argon and mercury vapor, or neon and sodium vapor, or mixtures of vapors. When the gaseous atmosphere of the device consists of, or compr ses a difficultly vaporizable material, such as sodium, it is advantageous to provide a heat conservator in 5 which the lamp is mounted to reduce the radiation of heat from the container of the device and thus to maintain an effective vapor pressure in said device I during the operation thereof. When an easily vaporizabie material, such as mercury, is present in the lamp device I a. heat conservator. for the lamp is advantageous, particularly for lamps of the high pressure, unsaturated vapor type, in order to maintain the high vapor pressure. A suitable heat conservator is a double walled jacket having the space between the wall thereof evacuated or filled with a gas having poor heat coductivity characteristics, or a single walled evacuated envelope enclosing the lamp.

The electrodes 2 and 3 are connected to the terminals 4 of a 220 volt, 50 cycle alternating current source. A choke-coil 5 is connected in series with said lamp device and a condenser 6 is connected in parallel with said lamp device I. A discharge device 1 of the negative glow type having 5 cold electrodes is connected in series with said condenser I. The choke-coil 5 and the condenser G are of such dimensions that they are approximately in resonance for the fundamental frequency of the alternating current source 4. The electrodes of the auxiliary discharge device are separated a distance of approximately 3 cm. and said auxiliary device has a gaseous filling therein consisting of a rare gas, such as neon, at a pressure of approximately 20 mm. The starting voltage of the auxiliary device I is approximately 210 volts so that it can be started on the voltage of the 220 volt current source.

When potential is applied to the above described circuit the auxiliary discharge device 1 starts into operation and current then flows through the circuit comprising the alternating current source 4, the self-inductance 5, the auxiliary discharge device 1 and the condenser E. The voltage builds up in the condenser 6 and a is in circuit for a very short period before the.

lamp device I starts into operation and the voltage across the electrodes of the auxiliary discharge device 1 drops below the operating voltage of the discharge in said device I immediately upon the start of said lamp device I to cut the condenser 6 out of circuit. When desired, the electrodes 2 and 3 are heated by the discharge current, instead of by separate heating currents,

in which case the condenser 6 remains in the circuit for a longer period than in the case where the electrodes 2 and 3 are preheated since the temperature of said electrodes 2 and 3 is low immediately after the start of the discharge in said device I and a comparatively high voltage between the electrodes 2 and 3 is necessary for the operation of the discharge in said device I. Under these conditions the voltage across the electrodes of the device 'I is sufficient to maintain the discharge therebetween in operation and consequently the condenser 6 is left in the circuit a short time after the lamp device I has started into operation. After the electrodes 2 and 3 have been heated sufilciently by the discharge the voltage in the series circuit 6 and l drops below the voltage required for the operation of the auxiliary discharge device I and the condenser 8 is cut out of circuit.

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 the 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 electrodes of the discharge device 1 are coated with an electron emitting material, such as barium oxide, when desired.

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

1. A circuit for starting and operating a gaseous electric discharge device comprising in combination, a condenser connected in parallel with said device, a-selI-inductance connected in series with said device, an auxiliary gaseous electric discharge device connected in series with said condenser, a current source for said first named device, the starting voltage of said auxiliary device being less than the voltage or said current source and the operating voltage of said auxiliary discharge device being greater than that applied thereto after said first named device has been started into operation.

2. A circuit for starting and operating a gaseous electric discharge device comprising in combination, a condenser connected in parallel with said device, a self-inductance connected in series with said device, an auxiliary gaseous electric discharge device connected in series with said consaid auxiliary discharge device being greater than i that applied thereto after said first named device has been started into operation.

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