US2659035A - Apparatus for operating gaseous discharge tube devices - Google Patents

Description

Nov. 10, 1953 P. K. RANNEY EI'AL 2,659,035 APPARATUS FOR OPERATING GASEOUS DISCHARGE TUBE DEVICES Filed Aug. 12, 1950 2 Sheets-Sheet l Fig. 2

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4 INVENTOR. PE/PP/m/ K 191mm? 3 (HA/PMS /P $4259.42

1953 P. K. RANNEY ETAL 9 3 APPARATUS FOR OPERATING GASEOUS DISCHARGE TUBEDEVICES Filed Aug. 12, 1950 2 SheetsSheet 2 I Fig.

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5 5% Tea/w, $2 5M Afiornews mmvroxs Patented Nov. 10, 1953 APPARATUS FOR, OPERATING GASEOUS DIS- CHARGE TUBE DEVICES Bercival K. Ranney, Lakewood, and Charles R. Kazehee, Cleveland, Ohio, assignors to The France Manufacturing 00., Cleveland. Oh o, a

corporati n of Ohio Application August 12, 1950, Serial No. 179,006

10 Claims. 1

This invention relat s to electric ga ous discharge devices gen r lly, and in particular. t starting and controlling the operation of gaseous discharge tube devices,

The problems which confront the industry in developing and constructing electrical gaseous discharge tube apparatus and operating systems relate principally to the operating characteristics of the discharge tubes in the apparatu and sys tem and t0 the Weight and overall size of the completed structure from the standpoint of cost, installation, and maintenance. Various form of apparatus and operating systems have been proposed to solve certain aspects of these prob.- lems by individually improving the structure of the apparatus, or by improving cooperating features of each in order to provide an overall im- Pr ved apparatus and system. By Way f example, such improvements are illu trated in L tters Patent of the United States No. 2,35 ,879

issued August 1, 1944 to P. K. Ranney in the term of a three coil transformer in circuit with a condenser and magnetic shunt which r l in balanced inductive and capacitive Characteristics in a two-1amp system, which improved the p wer factor of the operating system and substantially reduced the undesirable strohosconic effects of such a system.

The operation of aseous discharge tube devices, p rticularly with. respect to the startin and controlling of such operation, becomes more complex both electrically and physically when the number of lamps in the system is increase to three or four. Accordingly, the advantages of balanced circuit operation may be offset by less efiicient operation and a corresponding reduction of lumen output per watt input as the number of controlled tubes within a given circuit is increased.

Therefore, it i an object of this invention to increase the efliciency of operation of plural tube gaseous discharge tube systems by increasing the lumen output per watt input in plural tube gase ous discharge tube systems.

A further object of this invention is to improve the starting and operating characteristics of plural gaseous discharge tube systems in balanced circuit operation.

Briefly, in accordance with this invention, there is provided a gaseous discharge tube apparatus having a primary and plurality of secondary windings electrically coupled on a magnetic core and including means for connecting a discharge tube load in circuit relation with each of the se ndary windings. The secondary windings an be connected in aut trans orm r relation with the primary, and at least one of the sec- On ry i cui s inclu s a ries c p citance o pr id a. l ading current th r in while anothe secondary winding has a mag ti core shuntphys a ly positioned to reduce the magnetic coupling betw en that winding and the primary and thereby provide a lagging current in the correponding secondary c r uit. In addition, and in accordance with the objectives of thi invention another d schar tub is onnec ed in one of the secondary circuits and is shunted by a second capacitance.

These and other Objects and advantages of th invention will be further understood in the following desc iption when considered in conneo t o with the accompanying drawi gs and in h c p as p inted out in th appended claims.

In the drawings, Fig, 1 illustrates a wiring iaram of the power unit and lamps connected in accordance with this invention; Fig. 2 represents a simplified schematic diagram of the arraneement shown in Fi 1; Fi 3 is a simplifie schematic diagram of a modification of the Gil)- uit in Fi 1; Fi 4 represents a simplified s hematic diagram of another modification of he circuit of-Fig. 1.; his 5. is a simpl fi d scheot s i ram r an embodiment of this invention as applied to four fluorescent lamps; and g- 6 represents a simplified s hematic. diagram of a modification of the. embodiment of Fig. 5.

Referring now to Fig. 1, a source of alterna ing electrical current supply is shown connected to energize the primary winding H, which i mounted upon the central leg ll of a Shell -W9 m netic core H1. Sec ndary coil S! nd S1. are

also mounted on the central leg I I is spaced relac on ppo ite sides of he primary winding PI and electrically coupled thereto. A ma netic core shunt I: in the form of blocks of metallic laminations extends between the central leg H and the outer legs I3 and M respectively and is positioned between the primary winding PI and the secondary winding SI. The shunt should preferably be of such size as to provide suitable air aps indicated at [5 and [6 respectively.

T e discharge ube oad illustrated in el mbodies three fluo e ent discharge tubes l1, l8 n !9 which may be arranged in prop r r lation Within a suitable fixture. The secondary wind ngs SI and S2 are shown connected in parallel, auto trdnsformer relation with the pri ma y circuit. and each of the dischar tu o ds s co n c ed to re pec ive seconda y windin s. in seri s r at on s that tube I1 is energized by the secondary winding SI while tubes l8 and 19 are energized by the secondary winding S2.

The magnetic core shunt l2 provides a lagging current for the circuit of the lamp or discharge tube ll, whereas a series condenser 2e provides a leading current for the circuit of the lamps I8 andlil. The magnetic core shunt l2 aids in limiting the current in the circuit of the lamp H, and the condenser 28 aids in limiting the current in the lamp circuits [3 and if: to substantially the same value as that of the lamp circuit ll. Such an arrangement minimizes the stroboscopic effect and produces approximately unity power factor.

In the drawings, Figs. 1, 2, 3 and 4 represent different embodiments of this invention as applied to the operation of three fluorescent discharge tube lamps. The arrangement illustrated in Figs. 1 and 2 provides a parallel, auto-transformer connection for the lamp circuits enabling e the utilization of the additional voltage aiTorded by the auto-connection of the respective lamp secondary windings with the primary winding. Preferably, the winding arrangement may be such as to interrupt the flow of current in the primary circuit of the transformer whenever a discharge tube lamp is removed from its socket in the fixture as will be hereinafter more fully described. The arrangement of Fig. 3 illustrates a modification of the circuit in Fig. 1 wherein the secondary circuit of lamps I8 and I9 is not connected in parallel with the primary and therefore does not utilize the additional voltage afforded by the auto-connection of the primary and secondary windings as in Figs. 1 and 2. This circuit also provides for the interruption of the primary circuit upon removal of the discharge tube device. The arrangement illustrated in Fig. 4 represents another modification of the circuit of Figs. 1 and 2 wherein the primary and secondary windings are auto-connected directly and not through the condensers 2D and 2|. In this arrangement, the removal of any tube from the circuit will not necessarily interrupt the primary circuit.

Inasmuch as the basic principle of operation for all of the circuit arrangements illustrated is identical, reference will be made to Figs. 1 and 2 for an exemplary explanation. Upon energization of the primary winding Pl from a suitable alternating current power source an additive voltage will appear across lamp l1 due to the auto-addition of the primary and secondary voltages in the windings Pi and SI. This additive voltage is sufficient to initiate an arc discharge in the lamp H which will be stabilized by the action of the magnetic shunt l2 interposed between the windings and extending between the central leg and outer legs respectively of the shell type core.

The remainder of the circuit functions simultaneously in the following manner: Prior to ionization, lamps l8 and [9 present a very high impedance to the input circuit. Therefore, initially the voltage across lamp [8 will be zero, and the voltage across lamp l9 will be the additive voltages of the windings PI and 52 through condensers 20 and 2|. This additive voltage is of such magnitude as to be more than sufficient to cause an ionization current to flow in lamp 19. In the modified circuit of Fig. 3, the voltage is solely that developed by the secondary S2 and is sufficient to cause ionization. The series capacitors 2B and 2 I, limit this ionization current to a value insufilcient to initiate an arc discharge in lamp [9. The capacitors 20 and 2| are in effect a series capacitance in the secondary circuit, a portion of which is electrically by-passed by the lamp 18. Since the lamp I8 is connected in parallel with the capacitance 2|, the build-up of voltage across the condenser 2| will eventually reach the ionization potential of lamp l8, whereupon the inherent lamp resistance will rapidly decrease. As the lamp resistance decreases, the resulting impedance of the parallel combination of the capacitance 2| and lamp is is likewise decreased and causes the ionization currents of lamps l8 and I9 to increase until an arc discharge is formed in both lamps. The resultant are discharge is then stabilized by the ballasting action of the secondary inductive reactance and the series capacitance reactance of the capacitor 20.

In practice we have found it desirable to add a small resistance 25 in the secondary lamp circuit having the shunt capacitors 2| and 22 in order to smooth out the current wave form by damping out any high frequency components that may develop during operation. The resistor 25 should preferably be connected in series from the line side with the shunting capacitor 2! in Figs. 1, 2, 3, 4 and with the capacitor 22 in Figs. 5 and 6 as shown.

An example of a power unit and system assembly as illustrated in Fig. 1 may be described as using a source of alternating current supply at 118 volts and 60 cycles. The load circuit embodies three gaseous discharge tubes such as those designated as standard 40 watt fluorescent lamps. The transformer preferably has a core of the shell type with a central leg substantially 1" x 1%" cross section. The primary coil consists of 470 turns of No. 22 wire, while the secondary coils Si and S2 consist of 1,430 and 1,800 turns respectively of No. 26 wire. The capacitor section 20 has a capacitance of 1.5 mircrofarads, while the capacitor section 21 has a capacitance of 0.3 microfarad and the resistor 25 has a resistance of approximately 500 ohms. The air gaps of the shunts are so chosen as to result in a limitation of the current in the lag circuit to substantially the same value as the current in the lead circuit. With this assembly, the power factor will be approximately unity and an appreciable degree of stroboscopic correction will result by virtue of the phase displacement existing between the lagging and leading lamp currents.

The circuit arrangement shown in Fig. 5 illustrates an embodiment of this invention as applied to the operation of four fluorescent lamps. The lead circuit includes a primary winding Pl. a secondary winding S2, condensers 20 and 2| and lamps l B and I9 and is identical to that shown in Figs. 1 and 2 in both wiring arrangement and principles of operation. The lag circuit includes a primary winding Pl, a secondary winding Si. a condenser 22 and lamps ll and 23. Its operation likewise is similar to that of the aforerrem tioned lead circuit except that the current limiting action supplied by the condenser 20 in the lead circuit is accomplished in this circuit by means of the magnetic shunt 2.

The circuit arrangement illustrated in Fig. 6 is a modification of the embodiment shown in Fig. 5 wherein the parallel arrangement of the capacitance and discharge tube device is omitted from the lead secondary circuit. The circuit arrangement and operation remains basically the same as that described for the circuits of Figs. 1 to 5 except that the parallel arrangement of the capacitor and discharge tube are in the lag circuit only rather than in the lead circuit, as

acsaoac shown in Figs. 1 to 4, or than in both the la and lead circuits, as shown in Fig. 5.

This similarity is readily apparent when the operation of the circuits of Figs. 1 to 5 is compared to that of Fig. 6 which follows. Initially, in Fig. 6, the auto-additive voltage provides suflicient voltage in the lead circuit to initiate an arc discharge in the lamp l9. Stabilization of this discharge in the lead circuit is effected by the impedance of the capacitor 26. Simultaneously, lamp 23 in the lag circuit presents a very high impedance to the input, and the maximum open circuit voltage of the secondary winding SI, reinforced by the auto-voltage from the primary, is impressed across the lamp I in the lag circuit. This voltage is sufficient to cause an ionization current to flow in the lamp H, which current is limited initially by the impedance of the capacitor 22 and eventually by the combined impedance of the capacitor 22 and the lamp 23. This ionisation current develops a voltage across the capacitor 22 which increases with the current until it reaches the ionization potential of the lamp 23. As described in connection with Figs. 1 to 5, the resistance of the lamp 23 decreases during the flow of ionization current until an arc discharge is formed in lamps l1 and 23. The resulting discharge current is limited and stabilized by action of the magnetic core shunt l2 to about the same value as that of the lead circuit and the over-all power factor will be approximately unity.

In the circuit arrangements illustrated in Figs. 1, 2, and 3 the connections are preferably such that removal of a discharge tube from its socket interrupts the flow of primary current. The result of such action is to discontinue the flow of flux through the core and thereby to lower the secondary voltage to zero. This arrangement avoids the possibility of shock to anyone while a tube is out of its socket. One socket of each of the tube loads H, l8, and I9 is shown connected in the primary circuit so that the current flow in the primary circuit is through the sockets from one end of the respective tube loads to the primary winding Pi and back to the source of supply. Accordingly, removal of any tube in this circuit interrupts the flow of current in the primary circuit.

In some types of apparatus, the physical dimensions of the power unit are such that the leakage reactance component of the total lead circuit inductive reactance is increased to a degree, whereby the lead current Wave form varies from that of a sinusoid. Under such circumstances, various circuit variations and modifications can be made to compensate for this effect. For example, the primary and secondary windings can be subdivided into two or more individual sections and physically located with respect to each other so as to provide the same principle of operation as outlined above but still permit a degree of control over the leakage reactance of the various windings. In this manner, the proper ratio of capacitive to inductive reactance required for a sinusoidal lead current wave form can be properly maintained. The subdivided primary and secondary windings may be connected either in series or in parallel whichever best satisfies the particular design or construction.

The apparatus of this invention efiects a more efiicient operation of gaseous discharge tube devices such as hot cathode and cold cathode fluorescent lamps and by so doing provides more lumen output per watt input than analo ou prior art systems controlling the same number of lamps. The invention and its various cmbodiments illustrated herein are adapted to starting and controlling of lamp installations consisting of three or more lamps and, although units relating to the operation of three lamps and four lamps respectively have been described in comparative detail, the invention should not be limited to these configurations only, inasmuch as the main principles of operation can be ap-- plied to any larger number of lamps.

We have shown and described what we consider to be the preferred embodiments of our invention along with similar modified forms, and it will be obvious to those skilled in the art that other changes and modifications, particularly with respect to the number of operating lamps and their connection in the circuit arrangement, may be made without departing from the scope of our invention as defined by the appended claims.

We claim:

1. An apparatus adapted for operating a plurality of discharge tube loads from an alternating current source comprising in combination, a magnetic core, a primary winding thereon,

means for connecting the primary to the source,

a plurality of secondary windings electrically coupled to the primary winding on said core, circuit means connecting th primary and each of the secondary windings in auto-transformer relation, a gaseous discharge tube connected in series with each of the secondary windings, each tube having a pair of sockets, one socket 01' each tube connected to a corresponding secondary winding and the other socket of each tube having normally open contacts connected in series with the means for connecting the primary to the source, a series capacitance in one of the secondary circuits adapted to provide a leading current therein, a magnetic core shunt positioned on said core between another secondary winding and the adjacent primary winding to provide a lagging current in the correspondin secondary circuit of substantially the same value as said leading current, and a capacitance connected across one of said tubes in its secondai'i circuit.

2. The apparatus of claim 1 wherein the parallel arrangement of the second capacitance and other discharge tube is connected in series circuit relation in the leading secondary circuit having the series capacitance therein.

3. A fluorescent gaseous discharge tube 1ight-' ing system comprising in combination, a magnetic core, .a primary windin mounted thereon, a plurality of secondary windings electrically coup-led to said primary winding in spaced relation on said core, circuit means connecting said primary and secondary windings in auto-transformer relation, a plurality of discharge tube loads, a source of alternating current electrical energy, a tube load connected in series with each of said secondary windings in respective secondary circuits, each tube load including a pair of sockets for detachably receiving a discharge tube, the connection between th primary winding and said source of energy being in series through said tube sockets so that removalof the respective tube therefrom interrupts the source to the primary winding, a series capacitance .in one of said secondary circuits adapted to provide a leading current therein, a magnetic-core shunt positioned between the secondary winding of another secondary circuit and the adjacent primary winding to provide a lagging current therein of substantially the same value as said leading current, a second capacitance and another discharge tube connected together in parallel relation, said parallel arrangement being connected in series circuit relation in one of said secondary circuits.

4. The apparatus of claim 3 wherein the parallel arrangement of the second capacitance and other discharge tube is connected in series relation in the lagging secondary circuit having the magnetic core shunt associated with the secondary winding therein.

5. The apparatus of claim 3 wherein a parallel arrangement of a capacitance and a discharge tube is connected in series relation in each of the leading and lagging secondary circuits.

6. A fluorescent gaseous discharge tube lighting system comprising in combination, a magnetic core, a primary winding mounted thereon, a plurality of secondary windings electrically coupled to said primary winding in spaced relation on said core, circuit means connecting said primary and secondary windings in auto-transformer relation, a plurality of discharge tube loads, a source of alternating current electrical energy, a tube load connected in series relation with each of said secondary windings, each tube load including a pair of sockets for detachably receiving a discharge tube, a connection between the primary winding and said source of energy through said tube sockets so that removal of the respective tube therefrom interrupts the source to the primary winding, one of said secondary circuits including a capacitance in series with the corresponding discharge tube load, another tube load in said secondary circuit electrically by-passing a portion of said series capacitance, and a magnetic core shunt positioned on said core between said other secondary winding and the adjacent primary winding.

7. An apparatus adapted for operating a plurality of discharge tube loads from an alternating current source comprising in combination, a magnetic core, a primary winding thereon having means for connecting said winding to the source, a plurality of secondary windings electrically coupled to said primary winding in spaced relation on said core, a discharge tube load connected in series circuit relation with each of said secondary windings, and means connecting each of said secondary windings in parallel direct auto-transformer relation with said primary winding, one of said secondary circuits including a capacitance in series with the corresponding secondary winding to provide a leading current therein, a magnetic core shunt positioned on said core between said other secondary winding and the adjacent primary Winding to provide a lagging current in said other secondary circuit of substantially the same value as said leading current, another gaseous discharge tube, a second capacitance and a series resistance connected across said tube in shunt relation, said shunt arrangement being connected in series circuit relation in one of said secondary circuits.

8. A fluorescent gaseous discharge tube lighting system comprising in combination, a magnetic core, a primary winding mounted thereon, a plurality of secondary windings electrically coupled to said primary winding in spaced relation on said core, a discharge tube load connected in series relation with each of said secondary windings, each tube load including a pair of sockets for detachably receiving a discharge tube, a source of alternating current electrical energy, means connecting said primary winding in series with one socket of each tube load and said source of energy so that removal of the tube therefrom interrupts the source to the primary winding, means connecting each of said secondary windings in parallel, direct autotransformer circuit relation with said primary winding, one of said secondary circuits including a capacitance in series with the corresponding discharge tube load to provide a leading current therein, a magnetic core shunt positioned on said core between said other secondary winding and the adjacent primary winding to provide a lagging current in said other secondary circuit of substantially the same value as said leading current, another discharge tube load, a second capacitance connected across said tube load in shunt relation, said shunt arrangement being connected in series circuit relation with one of said secondary circuits.

9. An apparatus for operating a plurality of discharge tube loads comprising in combination, a closed magnetic core having a central leg and outer leg portions, a primary winding positioned on the central leg portion, a pair of secondary windings axially spaced on the central leg portion on opposite sides of said primary winding respectively, one of said secondary windings being loosely coupled to the primary and the other of said secondary windings being closely coupled to the primary, circuit means connecting each of said secondary windings in auto-transformer relation with the primary, a. source of alternating current, a gaseous discharge tube connected in series with each of the secondary windings, each tube having a pair of sockets, one socket of each tube having normally open contacts adapted to be closed by the tube and connected in series between the source and the primary windings, said closely coupled secondary circuit including a series capacitance to provide a leading current therein, a magnetic cor shunt positioned on said central leg portion between said loosely coupled secondary winding and the adjacent primary winding to provide a lagging current in said loosely coupled secondary circuit, said shunt being of a size to provide air gaps between the outer leg portions and the shunt sufiicient to limit the current in said loosely coupled circuit to substantially the same value as the current in said other secondary circuit, another gaseous discharge tube connected in series in one of said secondary circuits, and a second capacitance connected across said tube in shunt relation.

10. An apparatus for operating a plurality of discharge tube loads from an alternating current source comprising in combination, a magnetic core, a primary winding thereon, means for connecting the primary to the source, a plurality of secondary windings electrically coupled to said primary winding in spaced relation on said core, one of said secondary windings being loosely coupled to the primary and the other of said secondary windings being closely coupled to the primary, means connecting said secondary windings in auto-transformer relation with the primary, a gaseous discharge tube connected in series with each of the secondary windings, each tube having a pair of sockets, one socket of each tube having normally open contacts adapted to be closed by the tube and connected in series 9 with the means for connecting primary winding to the source, said closely coupled secondary circuit including a capacitor in series with the corresponding secondary winding, a magnetic core shunt positioned on said core between said loosely coupled secondary winding and the adjacent primary, said shunt having a configuration to limit the current in said loosely coupled secondary circuit to substantially the same value as the current in the closely coupled secondary circuit, and another capacitor connected across one of the tubes in the corresponding secondary circuit.

PERCIVAL K. RANNEY. CHARLES R. KAZEBEE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Aggers Nov. 3, 1942 McDermott Dec. 15, 1942 Boucher et a1. Aug. 8, 1944 Boucher Jan. 9, 1945 Ranney June 18, 1946 Kulka Mar. 15, 1949 Nathanson Mar. 22, 1949 Hindman Sept. 19, 1950 Gates Feb. 13, 1951 Peterson May 8, 1951

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