US2321072A - High intensity fluorescent lamp system - Google Patents

Description

Ma 4,1943. W, Q HALL, JR 2,318,072

HIGH INTENSITY FLUORESCENT LAMP SYSTEM Filed Sept. 24, 1941 ZLL ,ZT

A ,77-r-K Patented May 4, 1943 star ilNiiE s PATENT or ies HIGH INTENSITY FLUORESCENT LAMP SYSTEM Willard C. Hall, 31"., Los Angeles, alif.,assignor to Alfred P. Daniels, Los Angeles, Qalii.

Application September 24, 1941, Serial No. 412,124

6 Claims.

type lamps having end electrodes or cathodes which are heated to increase the fiow of electrons. At present, the cathodes of such tubular lamps operate at a given current density which forms a single hot or glow spot; the character and heat of this spot largely determining the life of the lamp. Should more than the rated current pass through the cathode, the hot spot there- 01' becomes too intense-and the filament rapidly deteriorates and breaks.

This'invention intensifies the illumination of standard gaseous electric discharge types of lamps by forming a plurality of hot or glow spots on the cathodes. By forming a plurality of hot spots,.each hot spot does not become overheated and the filament, therefore, does not rapidly deteriorate thus each cathode safely operates at Y greater electronic capacity. i

This invention intensifies the illumination of standard gaseous electric discharge types oflamps by forming a plurality of hot or glow spots on the stead of the lamp having all its lighting energy emanating from a single spot upon the cathode, a plurality of such spots supply the energy at a low temperature and forms a greater column of light giving properties throughout the active length of the lamp.

An object of this invention, is to present an electrical system for greatly increasing the lilumination of gaseous electric discharge lamps without shortening the useful life thereof.

Another object is the provision of a transformer device which is capable of forming a plurality of hot spots on a single cathode.

Still another object is to provide an electrical system for standard gaseous electric discharge Ii ils whichforms a plurality of hot spots on their filaments for materially increasing the emciency thereof at a high power factor; this being accomplished by a simple sturdy device economical tomanuiacture.

Other objects, advantages andfeatures of my invention will appear from the accompanying drawing, the subjoined detailed description, the

thereon.

preamble of these specifications and the appendto be understood that the drawing and description thereof are not to limit the invention in any sense whatsoever, except as limited by the appended claims.

In the drawing:

Fig. 1 shows a wiring diagram of the invention.

Fig. 2 shows in elevational view, parts being broken away, of a switch adapted for use inthe conductors 5 and 6, and the conductors. l and 8 respectively. Within the envelope are the electrodes or thermionic cathodes 9 and ill in the 8. low pressure rare gas such as neon OI argon and a few drops of a vaporizable metal such as mercury. The inner side of the walls of the tube are coated with a fluorescent material which materially brightens the lamp since the electrical discharge between the electrodes is scarcely visible.

The transformer comprises a plurality of laminated limbs, a large area central limb ll upon which is wound the primary coil i2. This cell has leads l3 and It at its ends which connect with a source of suitable electric pulsating current not.shown. A hand switch I4 is shown in the lead It. v

Outer limbs i5 and iii of the transformer have secondary coils i1 and I8 respectively wound The laminated bars [9 and 20 complete the magnetic path of the transformer. The coil H has one end connected to the conductor 5 and the other end to conductor 1. Shunting the 2|" and the condenser 22 with its leads 22' and 22". The other secondary coil has one end con-' nected to the conductor 6 which leads to the cathods 9, and the other end of which that connects with the conductor 8; the conductor 8 leading to the other cathode I0. I

The instantaneous polarity of the'secondary coils are indicated, and show that the instantaneous positive polarity of each coil is connected across one of the electrodes and the instantaneous negative polarity of .each coil is connected across theiother electrode. Therefore, when an alternating current; for instance,

at an impressed line voltage 01 and frequency of 60 cycles, is connected to the primary l2 through switch 14', like voltages and polarity, at any given instant, is impressed across one of thev electrodes, and the opposite polarity across the other electrode. This is the case when the 5 tube is in normal operation'by electronic bombardment.

To start the tube, the switch 2! and condenser 22 must function so as to first heat the cathodes and provide the higher voltage surge to strike the tube. The switch 2! may be of the gaseous electric discharge type now to be described, or it may be of the type that is closed when cold and open when hot.

In Fig. 2 of the drawing, a gaseous electric disl5 charge switch is shown which is especially adapted for use in this invention. The switch has a casing or envelope 21 which maybe of glass or metal, and has the glass press or seal 28 I which give support to the two bimetal strips 29 and 30, the strips having connection with the wire conductors 2| and 2|" as shown inFig. 1. One of the strips has a curled contactor 3| and the other strip has a plate contactor 32. The envelope is filled with any suitable ionizable gas such as neon. When current at proper voltage is connected across the leads of the switch, an electric discharge will take place between .the strips 29 and 30 and heat them. Upon heating,

the strips will flex toward each other'and their 30 ends make contact to close: the circuit; contact. having been made, the switch strips 29 and 30 cool and separate and thus openthe circuit to which they are connected. This switch when closed, at the start of operations, short circuits the coil ii and thus doubles the power out-put and voltage of coil [8 which is then in series withboth electrodes and provides the current to heat these electrodes.- When the filaments of these electrodes become hot, the switch 2i automatical- 40 1y opens (a matter of a few seconds) and connects like polarity ends of both coils to their respective electrodes. Immediately, the electrodes have opposite polarity at any instant, and are maintained at operating heat by electronic bombardment alone.

By the arrangementof this new system, two

- hot spots form on each electrode at their ends as indicated by the numerals 23, 24, 25 and 26.

These spots form conductive gas columns in the tube which merge to form an intensified principle conductive column which extends the ,major length of the tube. v The spots on each electrode do not tend to unite due to the resistance along the filament being greaterthan the ionized gas column. This action means that it is possible to run the tube at twice its normal current capacity and hence obtain nearly twice its normal brilliancy without injury to the cathodes or tube. Therefore, the life of the tube is not ters Patent is:

1. In combination, a gaseous electric discharge lamp with end cathodes and a transformer, the transformer having a primary coil, and secondary windings substantiallyin phase with their like polarity ends connecting across one cathode and the other opposite like polarity ends connected across the other cathode, and switch means connected across one of the windings to short it when the lamp is started.

2. In combination, a gaseous electric, discharge lamp with end cathodes and a-transformer, the transformer having windings substantially in phase with their like polarity ends connecting across one cathode and their other opposite like polarity ends connected across the other cathode, a switch and condenser having leads connecting opposite ends of one of the windings, the switch operating to short the winding when closed, and

a primary coil for energizing the windings.

3. In combination, a gaseous electric discharge lampv with end electrodes and a transformer, a primary winding for supplying power to the transformer, a plurality-of secondary coils, the ends of the coils having like polarity connecting across one of the electrodes and the other ends of the coils connecting across the other electrode, switch means forshort circuiting one of the'coils to allow the other coil to heat the electrodes in series.

4. In combination, a gaseous electric discharge lamp wih end cathodes and a transformer having threelimbs, a primary winding on one of the limbs having connection to a source of electric current, a secondary coil on each of the other two limbs, a conductor from one end of each coil connected across one of the cathodes and another-conductor from the opposite end of each coil connected across the othercathode, a switch connected across one of the coils for the purposes described.

5. The method of forming a plurality of hot spots on the cathodes of a gaseous electric discharge lamp by: providing across each cathode a like instantaneous polar voltage and maintaining thecathodes in opposite instantaneous polarities with respect to each other, and maintaining the spots on the cathodes separated by maintaining a lower resistance between the cathodes than between the spots.

6. In combination, a gaseous electric discharge lamp with a plurality of electrodes and a transthe opposite like polarity parts of the windings.

and switch means connected across one of the windings to short it when the lamp is started, the

shorting of said one of the windings connecting the other winding in series with said filaments.

.wnmap c. HALL, .m.

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