CA1186366A - Means and method for controlling lumen output and power consumption of phosphor excitable lamps - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A device and a method for reducing power consumption and correspondingly reducing lumen output of a phosphor excitable lamp, such as a fluorescent lamp, connected to a source of power for operation of the same, without any appreciable loss of operating efficiency. A load limiting arrangement, often referred to as a load limiting control device, and which generally includes a capacitive element is electrically connectable to one terminal of the phosphor excitable lamp. This device, when connected, is effectively electrically interposed between the lamp and the source of power in a series connection.
The capacitive element is selected with a capacitive value so that the lumen output is reduced but with substantially uniform lumen output at the reduced level and the power consumption is reduced without substantially changing the voltage to the lamp and without any appreciable effects on the efficiency of operation of the lamp or the source of power. Further when sing the device and method, a circuit path is not created directly between the conductive terminal of the socket and the end terminal of the lamp, but rather through the capacitive element to thereby reduce the power consumption and lumen output.
n addition the load limiting arrangement may adopt the form of a capacitive - indictive circuit arrangement. In a preferred embodiment, the device is constructed so that conductive pins on the device is inserted in the pin receptacles of the fixture and pin receptacles on the device are offset to receive the pins on the lamp.

Description

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1 1. Field of the Invention

2 This invention relates in general to certain new and

3 useful improvements in a means and method for reducing power

4 consumption of one or more lamps in a circuit arrangement and correspondingly reducing lumen output to a uniform lumen output 6 level, while maintaining efficiency of operation of the larnps and 7 the power source connected to the lamps for o~eration of the 8 lamps, and more particularly to a means and method of the type 9 stated which utilizes a load limiting control means for insertion in a series connection with respect to a lamp and the source of 11 power therefor.

13 2. Brief Description of the Prior Art 14 In many cases, conventional fluorescent light fixtures 1~ are constructed so as to physically retain and energize a pair of 16 phosphor excitable lamps, such as the fluorescent lamps. The 17 ballast and circuitry in these fixtures are typically designed so 18 that two lamps in a two-lamp fixture, for example~ are essential-19 ly electrically 180 degrees out of phase. This arrangement is 20¦ used in order to cancel out visible flicker to some extent.
21¦ Thus, two lights in a fixture or otherwise lights $n pairs are 22¦ employed to reduce the noticeable effects of flicker, even though 231 the extra lumen output of the two lamps are not necessarily required.

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2 In many cases, it has been found in office ~uildings and 3 other commercial installations, that it is possible to eliminate one or more lamps of the fixture without appreciably reducing total light output so that inefficiency and eye fatigue do not 6 result. In other words, many commercially available fixtures 7 were constructed so that an excess of light was generated for a 8 given purpose.
In recent years, and due at least in part to severe 9 shortages in available energy, and particularly electrical energy, and also due to the high cost of electrical energy, there 11 has been an interest in reducing the available light output in 13 order to reduce the total cost of operation. ~owever, in many of the commercially available fluorescent lamp fixtures, the removal 14 of one of the lamps, particularly in a series con~ected circuit 16 of the lam~s resulted in a very substantial inefficiency of 17 operation. If the remaining lamp was able to operate at all, depending upon the circuit configuration, then there was a 18 resultant inefficiency in that the remaining lamp produced less 19 li~ht output for a given level of power consumption, Gr other-22o wise, the ballast in the electrical circuit which operates the 22 larnp operated inefficiently thereby decreasing operating life.
23 In order to obviate these problems, there has been an introduction in the market place of the so-called "phantom tube".
24 The phantom tube is essentially a bulb or tube similar to that of 25 the fluorescent lamp or similar phosphor excitable lamp which was 27 removed and which is capable of being connected between the 28 t:erminals in a fluorescent larnp fixture. In this way, when one of the operating lamps was removed, the phanton, tube was inserted 1 ~ 31~
2 and the remaining lamp could operate with a reasonable degree of 3 efficiency. These phantom tubes, in one embodiment, employ a 4 capacitor connected between the sockets from which a lamp was

5 removed, such as the type described in U.S. Patent No. 3,956,665

6 to Westphal. In other cases, the phantom tube relied upon a non-

7 reactive lamp circuit, as for example, as described in U.S.

8 Patent No. 4,053,811 to Abernathy.

9 In each case, the phantom tube while effective in

10 permitting reduction in power, was oftentimes undesirable due to

11 the fact that it drew attention to the fact that one of the

12 operating lamps was removed. Thus, it always appeared as though

13 one of the lamps in a two lamp fixture was burned out and not

14 replaced. In addition, the removal of one or more of the lumen roducing lamps oftentimes created uneven light distribution and 16 as therefore ineffective for the desired purpose~ In addition to 17 the above, unless the capacitor or the power factor compensating 18 lement was not accurately established for a particular circuit, 19 here was a resultant power factor loss.
In addition to the foregoing, the lamp substitute 21 evices e.g. the so-called phantom tube, was ineffective, in 22 ome cases, due to the fact that it was not easy or convenient to 23 epair the phantom tube, particularly in the event of a capacitor 24 urn out. Moreover, inasmuch as these tubes were constructed 25 rimarily of glass or lightweiqht plastic material, they had to 26 e carefully packaged in order to reduce the incident of breakage 27 r damage during shipment and transporta~ion. This resulted in 28 n increase in the cost of the shipment and hence the cost of the l phantom tubes. ~10twithstanding, even with careful packacJing, 2 there was also a substantial rate of breaka(3e and damaqe as a 3 result of shipment and or that matter, improper handling during 4 storage.

S There has been at least one attempt to reduce po~er 6 consumption and also lumen output in a circuit configuration 7 which employed t~o or more fluorescent lamps. This one proposal 8 has been taught in U.S. Patent No. 4,135,115 to Abernathy et al.
9 ~lowever, in the Abernathy et al Patentt the device which is lO utilized is rather complex and includes a step-up transformer, as ll well as a plurality of capacitors and a resistive element. This 12 device is constructed so as to at least step-up the voltage for a 13 hort period of time in order to achieve starting of the lamp.
14 oreover, this particular device is only effective for use with he so-called "rapid-start" circuit and is not effective for use 16 n other circuit configurations, as for example, the so-called 17 instant-start" circuit, etc.
18 In addition to the above, the device in the Abernathy, 19 t al Patent is also relatively ineffective in that it must be 20 hysically connected in the circuit by disconnecting one or more 21 the electrical lines with respect to the ballast. Thus, it 22 ~s necessary to employ someone s~illed in electrical circuit 23 rk, such as a licensed electrician to disconnect the power, 24 eak one or more of the lines and connect the device taught in e ~bernathy et al Patent into the circuit arran~ement. ~This 26 sulted in down time, a substantial increase in installation 27c sts and further, a very substantial increase in cost of the 2 vice itself.

- ~ 3~ 1 The present invention obviates these and other pro~lems 3 in the provision of the very simple load limiting control means 4 which is capable of being inserted in the circuit without the necessary disconnection of any of the electrical lines.
6 Moreover, the device of the present invention is quite simple in 7 its construction and permits a reduction of lumen output with a 8 corresponding reduction of power consumption and which is highly 10 efficient.

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1 OBJECTS OF T~IE INVE~TION
2 It is, therefore, a primary object of the present 3 invention to provide a means for limiting the po~ler consumption 4 and the lumen output of a phosphor excitable lamp which is connected to a source of power for operation of the same without 6 any appreciable loss in efficiency of operation o~ either the lamp 7 or the power source, by utiliæation of a load limiting control 8 means interposed between the lamp and the source of power in a 9 series arrangement~
It is another object of the present invention to 11 provide means of the type stated which utilizes at least a 12 capacitor having a value selected so that the lumen output is 13 reduced and the power consumption is reduced by wi~hout 14 substantially changing the voltage which is applied to the lamp.
It is further object of the present invention to 16 provide a means of the type stated which is capable of being 17 electrically connected and disconnected without connecting or 1~ disconnecting anything other than the lamp.
19 It is also an object of the present invention to 20 provide a device which utilizes a capacitive element and/or 21 inductive element for limiting the power consumption and 22 correspondingly limiting the lumen output of a phosphor excitable 23 lamp which is normally connected between a pair of sockets in a 24 Eixture and where the capacitive element and/or inductive element ~51 an be interposed between an end terminal of the lamp and a 26 onductive terminal in the socket of the fixture.
27 It is still another object of the present invention to 28 rovide a method of limiting power consumption and lumen output ~ 6 2 of a phosphor excitable lamp connected to a source of power 3 without any appreciable loss o~ efficiency by electrically connecting a capacitive means or an inductive means or combina-tion thereof to one terminal of the phosphor excitable lamp and 6 electrically interposing this means between the lamp and the 7 source of power in order to reduce the power consumption anZ the 8 lumen output and yet maintain a high degree of efficiency of 9 operation of the lamp and the source of power.
It is yet a ~urther object of the present invention to 11 provide a method of reducing power consumption and 12 correspondingly reducing lumen output of a lamp by inserting a 13 device which has a capacitive value and/or an inductive value 14 selected to perform these functions without substan~ially changing the voltage which is normally applied to the lamp and 16 which does not require physical connection and disconnection of 17 any electrical components, other than the lamp.
18 With the above and other objects in view, my invention 19 resides in the novel features of form, construction, arrangernent 20 and combination of parts presently described and pointed out in 21 the clairns.

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2 BRIEF SUMMARY OF T~IE DISCLOSU~E

4 A means for limiting power coosumption and lumen output of a phosphor excitable lamp connected to a source of power for 6 operation of the same and which means pern;its such reduction 7 without appreciable loss in efficiency of operation of either the 8 lamp or the source of power.
9 The term "phosphor excitable" in connection with a light producing, electrically operable lamp, is deemed to include 11 those lamps which utilize an excitable phosphor in order to start 12 or maintain operation of the same and include for example, the 13 fluorescent lamp, the so-called "cathode discharge" lamp and the 14 electroluminescent lamp, etc. Inasmuch as these lamps are well known in the art, they are not described in any substantial 16 detail herein.
17 The means for reducing the power consumption generally 18 is a load limiting corrective means which may adopt the form of a 19 circui~ of a capacitive means or a circuit of a combination capacitive and inductive means, or both, and where the inductive 21 means, or the capacitive means, or both, is electrically connect-22 able to one terminal of the phosphor excitable lamp and is 23 effectively electrically interposed between the lamp and the 24 source of power in a series connection. This capacitive means is selected with a capacitive value so that the lu~,en output is sub-26 stantially reduced but yet is substantially uniform at the reduced 27 level. Moreover, the power consumption is substantially reduced 28 without chanying the voltage to the lamp and without appreciable -2 effects on the effic.iency of operation of the lamp or the source 3 of power.
4 The means of the lnvent.ion is h.ighly effective in that it permits interposition of the load corrective or compensatin~

6 means without electrically connecting or d.isconnecting any wire 7 or other component, other than the lamp itself. Moreover, the 8 invention is effective in that the means consists essentially of the conductors associated wlth a capacitor and/or inductor.

Thus, it is not necessary to employ any complex circuitry such as 11 complex transformers, integrated circuit chips or the like.
12 In one preferred embodiment of the invention, the 13 capacitive means has a capacitive value of from about eight microfarads to about fourteen microfarads. In a more preferred embodiment of the invention, the capacitive means has a capaci-16 tive value of from about two microfarads to about twelve micro-17 farads, depending on several factors, including the type of 18 ballast which is used. In like manner, the inductive means, 19 when employed in combination with the capacitive means has an ~nductive value of from about three mili-henreys to about 21 four mili-henreys at 1000 cycles.
22 The load limiting control means of the invention is 23 primarily effective in limitin~ the power consumption and lumen 2~ output of a plural.ity of phosphor excitable lamps, and prefer-ably, a plurality of such lamps in a seriès circuit arrangement, 26 that is where the lamps are in a series arrangement with respect to each o~her and with respect to a source of power for operation 28 of the larnps. In th.is case, as for example, where two such lamps are connected in a series arrangement, it is only necessary to ' ' 1~

2 use the load limiting control means with one of the lamps. This 3 will cause a reduction of lum~n output and a correspondlng 4 reduction of power consumption with respect to both lamps in the 6 fixture.
6 Typically, the fixtures which retain phosphor excitable 7 lamps, such as fluorescent lamps, are provided with pairs of 8 spaced apart sockets which receive the ends of the lamp.
9 Particularly, the sockets are provided with conductive terminals electrically connected to the circuit which provides power, as 11 for example, the ballast. Moreovert the lamps are also provided 12 with one or more terminals on each of the ends. The number of 13 terminals in many cases is dependent upon ~he type of operation 14 and the circuit arrangement used in the ballast. The invention ~6 is effective in that at least one end of the lamp is connectable 16 to the load limiting control means which is, in turn, connectable 17 to the conductive terminal in the socket. In this way, it is not 18 necessary to break any electrical lines or the like. Moreover, 19 it is important to note that a different electrical circuit path is established through the load limiting control means as opposed 21 to a circuit path from the end terminal of the lamp directly to 22 the conductive terminal in the socket. It is this different 23 electrical circuit path which permits the high degree of 24 efficiency in operation with the substantially reduced lumen output and power consumption.
26 In one effective embodiment of the invention, the load 27 limiting control means exists in the form of a device having at 28 least a relatively thin wafer which is capable of being 1 ~ ~;3~
2 interposed between the end terminal on the lamp and the 3 conductive terminal in the socket. This device is generally 4 comprised of a first conductive element which is adapted to be engaged by and establish electrical connection with at least one 6 end terminal of the lamp. The device also includes a second 7 conductive element which is adapted to engage and establish an 8 electrical connection with a conductive terminal of the socket.
9 An electrically non-conductive element is located between the two conductive elements. Moreover, the capacitor and/or inductor is 11 electrically connected to the two conductive elements such that 12 the circuit path is not established directly through the end 13 terminals of the lamp and the conductive terminal of the socket, 14 but rather through the load limiting control device itself.
In another embodiment, with respect to the device, the 16 aforesaid conductive elements and the non-conductive element are 17 suitably located ~ithin a housing and preferably an electrically 18 non-conductive housing. In this case, a recess is formed in the 19 housing to receive the end terminal, such as the pin, on the lamp. Moreove~, a prong is formed on the other side of the 21 housing and is connected to the first of the electrically conduc-22 tive elements for insertion into the socket. This prong will 23 essentially have the same size as the end terminal or pin on the lamp.
24 It is possible to insert the device of the invention between one end of the lamp and the socket inasmuch as the 26 fixture is generally constructed so that one of the sockets is 27 provided with a spring means to provide some leeway and space for 28 the lamp to be shifted back and forth for purpose of removal and 2 reinsertion.
3 One of the preferred embodiments of the present 4 invention does not require utilization of the spring means to provide some space for insertion of the load limiting control 6 means. In this embodiment of the invention, the load limiting 7 control means is constructed in the form of a housing so that it 8 is electri ally connectable to one of the terminals of a 9 conventional phosphor excitahle lamp, and to a socket which received that lamp, so as to be effectively electrically inter-11 posed between the lamp and the source of power in a series 12 connection. In this case, the control device is constructed so 13 that it has a first section capable of fitting with respect to 1~ the socket. More specifically, it is provided with at least one electrically conductive element, such as a prong, which is 16 inserted into an electrically conductive recess in the socket.
17 Ln addition, the device is provided with a second section offset 18 from the first section and adapted to receive the end of the 19 lamp, as for example, an end terminal of the lamp. This end terminal is received in an electrically conàuctive recess formed 21 in the second section of the device. In this embodiment of the 22 invention, the lamp may be offset from its original connection in 23 the socket by a slight distance.
24 This latter embodiment of the invention has been found to be very effective in that it does not require any snug 26 fitting enyagement and moreover, can be manufactured with the 27 desired tolerance in each, and which lends to convenience of 28 installation of the lamp.
The device of present invention is capable of operation - ~ ~B~ 3~; ~

2 with the so-called "instant start" light fixture using only the 3 capacitor. ~he device of the invention is operable with the so-4 called rapid start fixture in which a capacitor-inductor c~rcuit S is employed. In each case, the means for creating the reduction 6 of power consumption and lumen output relies primarily on the 7 capacitive means. In the first case, the capacitive means is 8 deemed to include that wafer and the electrical elements therein 9 as well as the non-conductive element therein, inasmuch as the electrically conductive elements and non-conductive element only 11 serve to establish a path through the capacitor. In other words, 12 there is no electrically effective element other than the 13 capacitor itsel. In the second case, the capacitor may be a 14 primary element but other elements may be present, e.g. an inductor and all serve as the load limiting control device.
16 This invention possesses many other advantages and has 17 ¦ other purposes which may be made more clearly apparent from a 18 consideration of the forms in which it may be embodied. These 19 forms are shown in the drawings forming and accompanying part of the present specification. They will now be described in detail 21 for the purposes of illustrating the general principals of the 22 invention, but it is to be understood that such detailed 2~ ~ scriptions are not to be taken in a limiting sense.

3 BRIEF DESCRIPTIO~I OF TH~ DRAWINGS

Having thus described ~he invention in general terms, 6 reference will now be made to the accompanying drawings in wnich:
7 FIGURE 1 is a side elevational view of a conventional 8 light fixture with phosphor excitable lamps mounted in the 9 sockets thereof;

FIGURE 2 is a bottom plan view of the fixture of 11 Figure l and showiny a pair of phosphor excitable lamps mounted 12 in-the sockets thereof and with a load limiting control means of 13 the present invention inserted between one of the ends of the 14 lamps and one socket thereof;
FIGURE 3 is an exploded side elevational view, 16 partially in dotted lines, showing the load limiting control 17 means in relation to one end of a conventional fluorescent lamp 18 and with respect to a pair of spaced apart sockets, 19 FIGURE 4 is a side elevational view, partially in phantom lines, and showing one form of load limiting control 21 device used in the present invention;
22 FIGURE 5 is a somewhat schematic vertical sectional 23 view showing the components forming part of the device of the present invention;

FIGURE 6 is an exploded side elevational view, somewhat 26 schematic in nature, and showing the interposition of the device 27 of Figure 5 with respect to an end of a lamp and a soc~et of the 28 fixture;

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2 FIGURE 7 is a vertical sectional view and showing a more detailed construction of one embodiment of a load limiting 4 control devlce constructed and in accordance with and embodying the present invention;

6 FIGURE 8 is a vertical sectional view of a modified 7 form of load limiting control device of the present invention;

8 FIGURE 9 is a side elevational view showing a phosphor 9 excitable lamp inserted in a fixture with one of the load limiting control devices of the present invention;
11 FIGURE 10 is a schematic side elevational view, 12 partially broken away, of Figure 9, showing in more detail, the lS portions of the load limiting control device and the means in 14 which the phosphor excitable lamp is connected;
FIGURE 11 is a bottom plan view, partially broken away 16 and showing an alternate àrrangement for mounting a lamp in a fixture;
17 ; FIGURE 12 is side elevational view, partially broken 18 away, and in section, and showing the details of construction 19 when using a pair of the load limiting control devices of the present invention;
21 FIGURE 13 is ~ side elevat.ional view of a preferred 22 embodiment of a load limiting control device of the present 23 invention, adapted for use with the rapid start circuit arrange-24 ment;
FIGURE 14 .is a schematic end elevational view of the 26 embodiment of the load limiting control device of Figure 13 and 27 used with the so-called~ "rapid start" circuit arrangement;
28 FIGURE 15 is an opposite end elevational view of the 1 ~ 3~;~
2 device of F.igures 13 and 14;
3 FIGURE 16 .is a schematic electrical circuit arrangement 4 showing the electrical comnponents in one embodiment of the load limiting control device of the present invention;

6 FIGURE 17 is a schema~ic electrical circuit view 7 showing the use of a load limiting aevice of the present 8 invention with one of the light emitting lamps in a two lamp 9 fixture, in a modified form of "instant start" circuit arrange-ment;
11 FIGURE 18 is a schematic electrical circuit view, 12 similar to Figure 16, and showing the use of a load limiting 13 control device of the present invention used with one lamp in ~ each of a pair of series connected fixtures in an "instant start"
circuit arrangement; and 16 FIGURE 19 is a schematic electrical circuit view, some-17 what similar to Figure 18, but show.ing the use of the load 18 limiting control device of the present invention used with one 19 lamp in a pair of series connected lamps in a "rapid start"

21 circuit arrangement.

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2 DETAIL~D DESCRIPTION OF PREFERRED EMBODIMENTS

4 Referring now in more detail and by reference charac-ters to the drawings which illustrated practical embodiments of 6 the present invention, Figures 1 and 2 show a conventional 7 fixture 10 of the type which holds and provides for eneryization 8 and resultant lumen output ~rom phosphor excitable lamps, e.g.
9 fluorescent lamps.
The fixture is generally provided with an outer housing 11 12 having a generall~ rectangular shape, as illustrated. More-12 over, depending from a bottom wall of the housing 12 are two 13 pairs of connector plates 14 and 14' and 16 and 16', as more 14 fully illustrated in Figure 2 of the drawings. Each of the connector plates are provided with soc~ets of the type normally 16 found in conventional fluorescent light fixtures. Thus, for 17 example, the connector plates 16 and 16' are provided with 18 sockets 18 and 18' respectivelyO Moreover, these sockets are 19 typically bayonet type sockets and include the conduc~ors therein for creating an electrical circuit through the phosphor excitable 21 ¦ lamp, such as a lamp L.
22 Figure 6 schematically illustrates a pair of conductors 23 in the socket 18 of the connector plate 16. ~oreover, and in 24 this case, the electrical conductors 20 which are often referred 25 ¦ to as "conductive terminals", are connected in spaced apart 26 relationship. In this way, a single pin tube may be used to 27 ¦ establish contact between the two conductive terminals 20.
28 l ~ 6 1 Also normally included within the housing, although it 2 may be located elsewhere, is a conventional ballast 22. ~he 3 ballast is electrically connected to the sockets and particularl~
4 the conductive terminals 20 in the sockets 18 and 18'.
Various circuit arrangements may be employed in these 6 conventional fluorescent Eixtures. For example, the circuit 7 arrangement may be that of the so-called "instant start" circuit 8 arrangement or the so-called "rapid start" circuit arrangement.
9 The embodiment illustrated in Figures 1-8 is generally desiyned for, although not exclusively desi~ned for, the instant start 11 circuit and the embodiment in Figures 9-14, is generally designed 12 for the rapid start arrangement. In any event, the fixture is 13 generally designed so that two or more phosphor excitable lamps, 14 such as the lamps designated as L and L in Figure 2, are

15 connected in a series relationship with respect to each other or

16 with respect to the ballast 22 or other power source. In like

17 manner, the fixture may be provided with a fuse cap 24 for

18 retaining a fuse in the electrical circuit including the ballast lg 22.
The typical fluorescent lamp is only one embodiment of 21 ~ phosphor excitable lamp as aforesaid, and is also a gaseous 22 ~ischarge lamp. The typical fluorescent lamp comprises a tube 23 ~, which is shown as having a straight glass tube, although the 24 :ube often adopts other shapes, as for example, a circular shape, 25 l ~r the like. One end of the tube is provided with a base or end 26 ~ap 2~ having one or more electrical terminals 30 at each end, 27 l )ften called "end terminals". A similar end cap 32 having one or 2~ lore terminals 34 (one as shown) is located at the opposite end 1 of the tube 26.
3 These terminals, which are also often referred to as "base pins", are connected to lead-in wires located internall~
4 witllin the tube, and the lead-in wires are located in a so-called "stem press" constructed of a material to assure the same 6 coefficient of expansion as the glass tube. The lead-in wires 7 are connected to a cathode which may be a hot cathode which is 8 designed to ignite a gas in the tube as hereinafter described.
The hot cathode is coated with an emissive material which emits electrons and is usually made of a coil~ e.g., a simple coil of 11 tungsten wire. In many commercial embodiments, a pair of similar 12 hot cathodes and related structure would ke included at each end of the glass tube.
14 The inside of the bulb or tube is provided with a 15 phosphor coating which trans~orms ultraviolet radiation into the 16 visible light. The color of the light often depends on the composition of the phosphor. A minute amount of mercury is also 18 located in the lamp to furnish the mercury vapor for purposes of

19 ignition. In addition, an inert gas, such as argon, krypton, and

20 the like, may be used. The coating on the hot cathode is

21 generally formed of an emissive material such as barium, 23 strontium, calci~lm oxide, or the like, and which emits electrons when heated to an operating temperature of about 950 degrees C.
224 ~ft~r the cathode has been heated to the proper temperature, 26 hermionic emission will occur. The emitted electrons, upon 27 ollision, will release ultraviolet radiation WiliCh iS converted nto visible light by the phosphors.

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The conventional electroluminescent lamp is comprised 1 of a plastic plate which is translucent and prefera~ly trans-3 parent in its construction. Applied to one surface of this plate is a phosphor coating and disposed against the phosphor coating is a metal sheet such as an aluminum sheet. Conductors are attached to the phosphor coating and the metal sheet. These 6 conductors are adapted for connection to a suitable source of 8 current through a baIlast, and in the case of the present invention, would be connected to inputs of the generator. The 9 electroluminescent lamp operates on essentially the same 10 principle as the gaseous discharge lamp. ~owever, in this case, 12 he phosphors are not located in a tube or bulb. The electro-uminescent lamp operates with a very high frequency creating a 13 apacitive effect across the phosphor coating and the metal sheet ith the phosphors converting the ultraviolet radiation into 16 isible light radiation.
17 Figure 3 is a somewhat schema~ic representation of the lteration occuring in the circuit arrangement when a load 18 miting control device of the recent invention is used with one more lamps. In this respect, it should be observed that the 21 vice is always used in a series connection with a single lamp 22 th respect to a power source. In the event where one or more

23 mps are connected with respect to a power source, such as a llast, and par~icularly in a series arrangement of the lamps,

24 e load limiting control device is also always used in a series 26c rcuit connection.

27 The term "power source" is also deemed to include that 28 rce of electrical power which may be the line power such as a ~36&~ , `'1 2 110 volt AC electrical circuit, or otherwise, the ballast itself.
3 Thus, in some cases, the input power is introduced directl~ into 4 the ballast, as in the so-called "instant start" arrangement.
Nevertheless, the ballast in this case is also deemed to be the 6 power source.
7 In the arrangement in Figure 3, it can be observed that 8 a conventional fluorescent lamp L is located between a pair of 9 sockets, as for example, the sockets 16 and 16'. At the left-hand end of the lamp L, a capacitive device A of the present 11 invention is inserted between the lamp and the conductive 12 terminal in the lamp socket. In the embodiment of the device 13 illustrated in Figures 1-7, the device is often referred to as a 14 "capacitive device" inasmuch as the primary electrical control element is capacitive in nature. In this case, it can be 16 observed that the device A includes a disc like housing 36 which 17 is capable of being fitted within the socket 18 o the connector 18 plate 16. Moreover, the end pin or end terminal of the lamp is 19 adapted to be inserted into the housing 36, in the manner as hereinafter described.
21 The load limiting or capacitive device ~ of the 22 invention is more fully illustrated in Figures 5 and 6 of the 23 drawings. In this case, the device A includes the outer housing 24 36. Moreover, included within the outer housing 36 is a first electrically conductive element 38 which is provided with a 26 projection 40 extending beyond the housing. In this case, the 27 projection 40 has essentially the san~e size and overall shape as 28 the terminal pin 30 of the lamp. In addition, the housing 36 is - ` ` ~?~3~6 1 sized to extend into the socket or at least a portion of the 2 socket 18, as aforesaid. Thus, when the housing is so inserted, 3 the yrojection 40 will contact the conductors 20 ~rithin the socket, much in the same manner as the end pin 30 on the lamp L.
It should also be understood, in connection with the present 6 invention, that when bi-pin or double-pin lamps are used, the 7 device A would also be provided with a similar pin arrangement.
8 This latter double-pin arrangement is usually employed with the 9 rapid start circuit arrangement. The device A also includes a ~0 second electrically conductive element 42 and which is spaced 11 from and insulated from the conductive element 38 by an 12 electrically non-conductive ~lement 44. The housing is also 13 provided on its right-hand end, reference being made to Flgures 5 14 and 6, with a recess 46 which opens into the conductive element 15 42. Thus, when the load limiting control device A of the 16 invention is used, the end terminal or pin 30 on the lamp L will 17 extend through the recess 46 and contact the conductive plate ~2.
18 By reference to Figure 6, it can be observed that the 19 housing 36 is preferably in the form of a relatively thin disc-20 like member. Consequently, in many cases, it is not easy to 21 include the capacitor directly in the housing. In this case, 22 ~here the capacitor cannot be included in the housing, a pair of 23 leads 48 and 50 are connected to the respective electrically 24 ~onductive elements 38 and 42 and whiçh are in turn, connected to

25 ~ capacitor 52. The capacitor itself may also be enclosed within

26 I suitable housing, in the manner as illustrated in Figure 4,

27 uch that a complete individual housing is connected to one

28 ocket as for example, a recess to receive the terminal pin or ` ~ 366 1 ...
2 pins at the end o the lamp.
3 The load limiting control device is also designed and 4 sized so that it is capable of being disposed within a socket of the connector plate. The pin on the end of the larnp would then 6 fit within a recess on the capacitive device. ~lowever, it should 7 be understood that the capacitive device could be designed so 8 that it fits over the end of the pin on the tube, with the prong 9 of the device extending into contact with the conductive elements in the socket. One such embodiment where the device fits over 11 the end of the pin is hereinafter described in detail.
12 In the embodiment of the device as illustrated, it can 13 be observed that the housing 36 is preferably formed of an 14 electrically non-conductive material. In this way, if a capacitor is still charged when one attempts to remove the 16 capacitive device, there will be no potential damage or injury.
17 In this respect, the housing includes a portion which ex~ends 18 into the recess 46 so as to electrically isolate the same. Con-19 sequently, it would be difficult for one to stick his or her finger into this recess. Even if the user of the device 21 attempted to contact the projection 40 he or she would not be 22 able to contact the conductive element 42 and thus, no 23 electrical short could occur, even though the capacitor 52 had 24 some residual charge.
It can be observed particularly from Figure 6, that 26 when any of the load limiting control devices of the invention is 27 used, an entirely different circuit path is estahlished. In this 28 case, as opposed to a circuit path being created from the ~ 366 2 ~ term.inal, e.g. the terminal pin 30 on the lamp directly to the 3 ¦ conductive terminal 20 in the socket, the path is created through 4 I the terminal pin 30, the conductive element 42, the capacitor 52, 5 I the conductive element 38, project.ion ~0 and then the conducti~e 6 I terminal 20.
7 l The capacitor has a capacitive value established so as ¦ to minimize any power factor loss or load control loss and to 8 ¦ mainta.in a high degree of efficiency of operation. It has been 9 ¦ found in connection with the illustrated device, that the 10~ capacitive value may range from about eight microfarads to about 121 fourteen microfarads. In a more preferred embod.iment, the 131 capacitive value of the capacitor used should range from about 141 two microfarads to about twelve m.icrofarads. Generally the capacitive valve for a device used in an instant start circuit 16 should range from about two m.icrofarads to about six microfarads 17 and pereferably from about three microfarads to about three and 18 one-fourth m;.crofarads. In the rapid start circuit, as 19 hereinafter described in more detail, the capacitive valve should ~ormally range from about four to about twelve microfarads and preferably from about ten to about twelve microfarads for the IIO
21 and HV0 lamp arrangements.

23 It has been found that on. the average, electrical 24 power reduct.ion is about 30~ in a two lamp circuit arrangement and the illumination is reduced about 27%. Consequently, there 26 does not appear to be any significant loss in percentage of 27 illumination with respect to the percentage in power reduct.ion.
28 In fact, there has been found to be an overall uexpected efficiency in terms of illumination with respect to power ~ 66 1 reduct.ion. Equally important ls the ~act that the ballast and 2 the lamps and the l.ife of these components are not damaged.
3 Contrarywise, the life of the lamp and the ballast itself has 4 increased substant.ially by virtue o~ the reduction of power used in operating both.
6 Figure 7 illustrates one preferred embodiment of a device R which may be used. In thls case, the device e generally 8 comprises an outer housin~ 54 which is preferably formed of a non-conductive material and which is provided with a central opening 56 along one of the flat walls thereof, as the left-hand 11 flat wall, in the manner as illustrated in Figure 7. Located 13 within the housing 54 is an electrically conductive strip 58 14 which is curved and shaped so as to form a shape similar to that of the projeetion 40. Moreover, the shape of the strip 58 which 16 forms this projection is similar to that of a pin, such as the 17 terminal pin 30 on the lamp. By reference to Figure 7, it can be observed that the strip 58 does not extend all the way into the 18 housing but is spaced apart from a similar strip 60 which is seeured within the housing 54 and extends outwardly therefrom to aid in the formation of a shape equivalent to that of the projec-22 tion. Also located within the housing 54 is a second conductive 23 strip 62. ~he conductive strip 58 .is connected to a firstelectrically conductive wire 64 by means of a clamp 66. A second 24 electrically conductive wire 68 .is con~nected to the strip 62 by means of a clamp 70 also in the manner as .illustrated in Figure 26 7. These two electrically conductive wires 64 and 68 would be 27 suitably connected to a capacitor, such as the capacitor 52.
28 The right-hand end of the housing 54 is provided with a ~ ;3~

1 recess 72 having a size and shape similar to the terminal pin 30 2 on any one of the fluorescent lamps. In this case, the recess i5 3 at least partially open so that a terminal pin on the lamp will 4 contact the conductive strip 62 loca~ed adjacent to the recess.
Also located within the housing 54 is an insulator 6 which surrounds the conductive strip 62 and electrically 7 tnsulates the same frorn the conductive strip 60 or the conductive 8 strip 58 which forms the projection. In this way, the equivalent 9 structure o that illustrated in figùres 5 and 6 is achieved.

This embodiment of the capacitive device has been found to be 11 highly effective and is easy to manufacture and moreover, is 12 relatively easy to repair.
13 Figure 8 illustrates a device C which is designed to fit over the end of a pin on a fluorescent tube or similar phosphor excitable lamp and have a projection thereof extend into the socket of the lamp. In other words, this device is 17 capable of fitting over the end of the tube, e.g., on the pin as 18 opposed to being inserted into the socket itself. The device C
19 generally comprises an outer housing 80 which is preferably formed of an electrically non-conductive material, such as a 21 plastic, or the like. Extending outwardly from one side of the 22 housing 80 is a metallic prong 82 which is of a size similar to 23 that of a pin on the end of a fluorescent lamp. Thus, this pro-24 jection 82 is sized to extend within the socket which normally receives a conventional fluorescent lanlp.
26 The projection 82 is provided with an outwardly flaring 27 flange 84 serving as a terminal within the housing 80. ~n

29 ~ 6 l electrically conductive wire 86 .is connected to this fla~ge ~4.
2 In addition, a cylindrically shaped ring 88 is also located on 3 the opposite side of the housing with respect to the projection 4 82 and is effectively electrically insulated by the housing from the flange 84. The ring 88 is also electr.ically connected to a 6 conduct.ive wire 90. Moreover, the conductors 86 and 90 are 7 connected to a capacitor of the type previously describeZ.
8 Figure 17 illustrates a circuit arrangement and parti-9 cularly the so-called "instant start" circuit arrangement in which a pair of fluorescent lamps L and L are connected in ll series. In this case, a load limiting control device, e.g7 a 12 capacitive device, has been used with the lamp L . It can be 13 observed that the capacitive device of the invention has been 14 inserted at the left-hand end socket although it could be located on the r.ght-hand end socket.
16 Typically, many of the fluorescent lamp fixtures 17 usua~lly include within the fixture, a black colored lead and a 18 white colored lead, the black colored lead designating the so-l9 called "ground" terminal as in a conventional 120 volt electrical power line. Moreover, conventional fixtures often include a blue 21 colored electrically conductive line and a red colored 22 electrically conductive line. These latter two electrical lines 23 or wires are generally connected to one of the coils in the 24 transformer of the ballast. In the preferred embodiment of the invention, the capacitive device is preferably used at that 26 socket wh.ich includes either the blue conductor or the red 27 conductor and preferably that socket wh.ich has the blue conductor 28 connected thereto.

3~6 2 F.ig~re 18 illustrates a circuit arrangement very 3 similar to F.igure 17 although two such f.ixtures using the .instant 4 start circuit arrangement are connected in series. ~ere again, the capacitive device is shown as being located in conjunction 6 with the lamp L in one of the fixtures and a similar lamp L in 7 the next adjacent fixture. No capacitive devices are used in 8 connection w.ith the lamps L in either of these fixtures. In 9 accordance with the above, it can be observed that the circuit path is changed in both the rapid start and the instant start 11 circuit arrangements. Moreover, the circuit path is chanyed by 12 the mere insertion of the capacitive device in the tandum circuit 13 arrangements as illustrated in Figure 18.
14 Figure 9~16 and 19 more fully illustrate an embodiment of the invention used with the so-called "rapid-start" circuit 16 arrangement~ In this case, a load limiting control device desig-17 nated by reference numeral 100 and forrrling th.is embodiment of the 18 invention is used to connect a typical conventional rapid-start 1~ lamp L to the sockets 18 and 18', respectively, in connector plates 14 and 14' which form part of a conventional fluorescent 21 lamp fixture. This fixture is similar to the type used for 22 retaining the instant-start lamps, as illustrated in connection 23 with the embodiment of the invention shown in ~igures 1-8. Elow-24 ever, in the instant-start lamp arrangement, typically one pin is centrally located on each of the opposite ends of the lamp and 26 the fixture is adapted to have one pin rece.iving aperture on each 27 of the opposite sides to receive the associated pins. On the 28 other hand, in the rapid-start c.ircuit arrangement, the lamps are i `3L~8~;3~;6 1 typically prov.ided with a pa~r of spaced apart conductive pins or 2 term.inals on each of the opposite ends of the lamp. In like 3 manner, the sockets forming part of the fixture are each provided with a pair of pin receiving apertures adapted and located to receive the pairs of pins on each of the opposite ends of the 6 lamp.
7 In the embodiment of the invention as illustrated in 8 Figures 9 and 10, it can be observed that one end of the lamp 9 (the right-hand end, as illustrated) is normally inser~ed into the socket 18' of the connector plate 14'. ~lowever, the 11 opposite, or left-hand end of the lamp L as shown in Figures 9 12 and 10, is displaced downwardly from the socket 18 in the 13 connector plate 14 in the final connected position. Rather, the ~ left-hand end of the lamp L is connected to a first portion of the load limiting control device 100 and which also has a second 16 portion connected to the socket 18 and the connector plate 14.

17 The load limiting control device 100 is more fully 18 illustrated in Figures 9 ana 10 and generally comprises a main 19 outer housing 102 preferably formed of the upper section which is designated by reference numeral 104 and the lower section which 21 is des.ignated by reference numeral 106.

22 The outer housing 102 is preferably formed of a molded 23 plastic material as, for example, polyethylene, polystyrene, 24 polybutadiene, various co-polymers thereof, or the like. In essence, .it is important that the housing be constructed of a 26 material which is effectively electrlcally inert. In th.is 27 respectr various reinforced plastic compos.ite ma~erials may also 28 be employed in construction of the hous.ing 102 and the associated ~l~86;~

l components.
2 The outer housing 102 is preferab1y formed ~ith the 3 upper section 104 and the lower section 106 in such rnanner that 4 the upper section 104 is capable of being lnserted into a socket in the fixture and the lower section 106 is capable of receiving 6 one end of the la~p L. Referring to Figures 9 and 10, as well as 7 Figures 13-15, it can be observed that the upper section 104 is 8 actually the upper section when fitted within the socket of a 9 fixture. The conventional fluorescent lamp is normally inserted into a socket and rotated approximately 90 degrees to be retained ll therein. Upon removal of the lamp, it is first rotated 12 approximately 90 degrees in the opposite direction. In normal 13 use, and before actual connection to a lamp and to a fixture, the 14 lower section actually is displaced to one side about 90 degrees much in the manner as the lamp. When rotated ahout 90 degrees 16 after being inserted in the fixture socket, the lower section 17 for purposes of installation, shifts from a position where it is 18 aligned with the upper section (in a horizontal plane) to a l9 position where it is disposed beneath the upper section.
Figure 11 illustrates an embodiment of the invention 21 where one end of the tube is fitted within one socket of the 22 fixture and the opposite end of the tube is fitted within the 23 load limiting control device. However, when in the final mounted 2~ position, the second end is offset laterally from the other end or first mentioned end of the tube as opposed to being disposed 26 below the first mentioned end of the tube as illustrated and 27 described in connection with the embodiments of the invention 28 illustrated in Figures 9, 10 and 12-15. The lateral offset is ~ ;3~

2 preEerred where tollerance space is not suficient fGr two or 3 l more lamps in certain ~.ixtures. Otherwise the vertically 4 d.isposed arrangement as illustrated .in ~igures 9, 10 and 12-lS
can be employed. The remain.ing details o~ operation are 6 essentially the sarne.
7 Again referring to Figures 11 and 13-16, it can be 8 observed that the lower section 106 is formed by a front wall 9 107, and a rear wall 108 connected by a bottom wall 109. A

somewhat U-shaped upper wall 110 connects the front and rear 11 walls in the manner as illustrated, and as best seen in Figure 12 13-15. The somewhat U-shaped upper wall 110 actually forms a 13 receptacle constructed and arranged so as to receive the end 14 portion of a conventional phosphor excitable lamp. The front and rear walls 107 and 108 respectively, along with the bottom wall 16 109 and upper wall 110, ~hich are all integrally formed 17 together, form an upper load l~miting electronics receiving compartment 112.

1~ Disposed over the r.ight-hand end of the housing 102 and rigidly secured thereto, by means of adhesives or other means 21 known in the art, is an end wall 114. This end wall is designed 22 to enclose the upper load limiting control electronics 23 compartment 112.
~4 At its left-hand end, the housing 102 is similarly pro-vlded with an end wall 118 in the manner as .illustrated. The end 26 wall 118 is typically adhes.ively secured to the housing 102 and 27 is initially separated therefrom for purposes of insert.ing the 28 elec~rical components in the lcad limiting control electron.ics l 34 ,, ~ i36~i 1 component com~artment 112, in the manner as ~lereinafter 2 described. The end plate 118 may be suitably secured to the 3 housing 102 by a number of known effective conventional 4 adhesives.
Integrally formed with the lower end of the end plate 6 118 is an extended section 120 and which is designed with an 7 internally formed socket 122, the latter also having a pair of 8 spaced apart pin receiv.ing receptacles 124. In this case, the 9 pin receiving receptacles 124 are each located and sized so as to receive the pair of end pins on the lamp L.
11 The upper housing section 104 is similarly provided 12 with a pair of outwardly struck spaced apart pins 126, which 13 protrude through the end plate 118, and which are located and 14 sized so as to extend into the pin receiving receptacles 127 lS formed in the socket 18 on the connector plate 14. Thus, it can 16 observed that when the pins 126 are located in a posit.ion where 17 they are rotated 90 degrees away from their final position, that 18 is when the device .is installed and retained in the socket 1~, 19 they will ultimately be rotated to the same position that the pins of a lamp would be when retained in the socket 18. Further, 21 since the left-hand end of the lamp L has .its pins located w.ithin 22 the pin receiving receptacles 124, it will then be positioned 23 beneath the connector plate 14 of the f.ixture.
24 Located within the load lim.iting control electronics component compartment 112 is a capacitor 128 and a transformer 26 130, the latter primarily serving as an inductive dev.ice.
27 Furthermore, a temperature sens.itive current control device, as 28 for example, a so-called "thermal cutoff" 132 is also connected .: ' 1 in series with the capacitor 128 and which is also connected 2 across a primary coil 134 and a secondary coil 136 forming part 3 of the transistor or sirnilar inductive device. This electrical 4 circuit arrangement is more fully schematically illustrated in Figure 16 of the drawings.
6 In this embodiment of the invention, the primary 7 effective electrical component is the capacitor 12~. E~owever, it 8 is important that the capacitor 128 operate in conjunction with 9 the inductive device 130 as, for example, the transformer 130.
Furthermore, it is preferably, although not necessary to include 11 the temperature control device 132 in the circuit arrangement.
12 The temperature control device 132 operates as a switch w~ich opens when the temperature exceeds a certain threshold level.
14 By further reference to ~igures 11 through 15, it can be observed that the electrical components in the compartment 112 17 are electrically connected to the pins 126 and also to the pin receiving receptacles 124 in the desired electrical arrangement.
18 In other words, the transformer interrupts the load from the 19 source of the power directly applied to the lamp. Furthermore, 21 the capacitor 128 is connected directly across one of the load lines and the lines to the lamp. The temperature control device 22 is, in series with the capacitor 128 and the physical connections 23 therefore, are more fully illustrated in Figures 13-15 of the 24 drawings.
It should be observed in connection with the construc-26 tion of the housing 102 that the electrical components as for 28 example, the tranformer 130, the thermistor 132 and the capacitor ~-` ~ 36~
l 128 can be easily ins~rted in the compartlnent 112, particularly, 2 the compartment 112 prior to seal.ing of the end wall 118.
Moreover, electrical connect.ions can be made via the various 4 conductors as illustrated pr.ior to the seal.ing of the end wall 118. Mevertheless, after the various connect.ions have been made, 6 sealing of the end wall 118 .insures permanent retention of the var.ious electrical components.
8 In accordance with the schematic circuitry as shown,in Figure 16 and the physical arrangement as illustrated in Figures 15-17, it can be observed that the capacitor 128 is again interposed in a circuit arrangement so as to alter the original 13 electrical circuit path between the source of power and the lamp.
This holds true even with the presence of the inductive device 14 as, for example, the transformer 130 and even the inclusion of the temperature control device 132. In any even~, it is apparent 16 that the capacitor 128 is interposed in the circuit arrangement, much .in the manner as previously described in connection with the 18 instant-start circuit arrangement By further reference to Figures 9 and 10, it can be 21 observed that the lamp L is connected between the pair of spaced 22 apart sockets much in the manner as illustrated in connection with the instant-start arrangement. ~lowever, it should also be 23 understood that this load l.imiting control device, as shown in 24 connection with the rapid start arrangement, could be equally employed with the .instant start arrangement. The only difference 26 is that there is an offset to one end of the lamp. Th.is is 2r nevertheless, highly effective in that it eliminates problems of 8 attempting to insert the lamp in a small conf.ined space.

~g36366 2 While it is possible to use the ~reviously descri~ed 3 embodiments o~ the invention on one end of the lamp with the 4 capacitor connected .in such a manner that this or.igi.nal circuit is .interrupted and rearranged, it is more efficient to use th.is 6 embodiment of a load limiting control device wherein one end of 7 the lamp is physically displaced from the original socket. This 8 permits the necessary and desirable space requirements to be achieved in terms of providing for th~ electronic components, connection of the p.ins in the lamp to the device, and connection 11 of the device to the socket of the fixture.
12 When further considering Figures 9-10 and 12-15, it can 13 be realized that the lamp is initially inserted within the 14 receptacle created by upper wall llOo Thereafter,the lamp is rotated in the device until it is retained therein. Mext, the 16 pins at the opposite end of the lamps L are inserted into the 17 socket 18' and the pins 126 are inserted in the pin receiving 18 receptacle 127. Thereafter, the lamp and the device are 19 simultaneously rotated along the axis of the lamp, 90 degrees so that the lamp and device ult.imately end in a position as Zl illustrated in F.igure 10 for example, that is where the left-hand 22 end of the lamp is slightly below the orig.inal socket. In the 23 case of the embodiment illustrated in Figure 11, one end of .the 24 tube is laterally offset and not below the end of the next adjacen~ tube or lamp.
26 This offset arrangement is not distract.ing to, or even 27 readily observable, to a viewer. Particularly, when using long 28 length lamps as, for example, an eight foot lamp or a t.en foot ~i~;36!G
-1 lamp, the fact that the left-hand end of the lamp has been 2 displaced a matter of an inch or so from the oriyinal socket is 3 not readily observable to a viewer. Figures 9, lO and 11 have 4 only been exagerated to more ~ully .illustrate the mounted relationship of the lamp to the fixture.
6 Nevertheless, it .is also realized that both lamps in a 7 fixture, or for that matter, all of the lamps in the fixture are 8 still operating and providing a lumen output. The very ~act that 9 .the lumen output is being generated further disguises the fact that one end of the lamp may not be physically inserted in a 11 socket o the f.ixture, but rather displaced a very slight amount 12 therefrom. It is, however, this displacement which permits a 13 very easy and convenient manufacture of the load limiting control 14 devices of the present .invention.
Figure 12 of the drawings illustrates an embodiment of 16 the invention where a load limiting control device 100 is used at 17 the left-hand end of the fixture and a load limit.ing control 18 device 140 is used at the right-hand end of the fixture. The 19 load limiting control device 140 is substantially identical to the load limiting control device 100 as previously described, 21 except for the fact that the load limitng control device 140 does 22 not include any of the electron.ic components as previously 23 described. In other words, the electrically conductive sockets 24 124 are connected directly to pins 126 on the upper section of the device 140. This is clearly observable in the manner as 26 illustrated in Flgure 12 of the drawings.
27 The embod.iment of the invention as illustrated in 28 Figure 12 is very similar to the embodiment of the .invention as 36~

1 lllustrated in Figures 13-15, o the drawings as aforesaid, as 2 well as in Figure 11. The only difference is that the load 3 limiting control device 140 ~oes not establish any different orm 4 of electrical circuit path,sinc~ the alteratlon of the circuit path is created ~y the load limiting control device 100. ~ence, 6 when using both load limiting control device 100 and the load 7 limiting control device 140, an identical electrical path is 8 achieved even as if the load limiting control device 140 were not 9 employed. The advantage of the load limiting control device 140 is that it acts as a companion to the device 110 and permits both 11 ends of the lamp tc be located essentially at the same elevation.
12 Returning now to the electrical circuit arrangement, it 13 can be observed that the impedance of all of the components of 14 the circuit effectively constitutes the major part of the total resistance in the circuit. The capacitive member as, for 16 example, the capacitor 128 is clearly a major component in the 17 circuit which alters the electrical circuit path and this 18 capacitor 128 restricts the current flow in the circuit. The 19 inductor as, for example, the transformer 130, is primarily 20 designed to maintain the filament voltage. The capacitor, on the 21 other hand, is effectively designed to match the irnpedance of the 22 circuit back to the ballast itself.
23 The device which is interposed between the lamp ànd the 24 ixture to alter the circuit arrangement is truly an impedance 25 corrective device inasmuch as the tube makes a contact wlth the 26 ixture and with the load limiting control device, the ballast 27 ffectively bel~eves that it has a lower impedance than is really ~ 3~

1 the case. Consequently, a reduced current flow .is generated from the ballast.
3 Notwithstand.ing any of the foregoing, it is realized 4 that the load llmiting control device of the present invention ,and .in the particular embodiments as illustrated ln F.i~ures 9-16 6 are h.ighly effectiveO In one specific embodiment of the device 7 100, the housing 102, has an overall vertical dimension of 8 approximately two inches~ the end walls 114 and 118 each have an 9 approximate thickness of about 0.080 inches in maximum. In addition, the socket formed by the wall 108 has a radius of 1 approximately 0 .750 inches~ Further, the diametral center point 12 of the socket is spaced from the lower edge of the housing 102 by 3 approximatexly 1.0 inches.
14 Figure 19 illustrates a socket arrangement using one standard form of rapid start ballast designated by reference 16 numeral 142. The ballast is connected to a pa.ir of lamps L with 17 the load limiting control device inserted with respect to the lamp 18 L in the manner as illustrated. Tests conducted with the load 19 limiting control device used in conjunction with the rapid start circuit arrangement have shown that the device is equally as 21 efficient as with the previously described instant start circu.it 22 arrangement. However, in connection with the rapid start circuit 2X arrangement, it has been found that the most effic.ient results 24 have been obtained when the capacitor 128 has a value of approxi-mately 3.5 microfarads.
26 In one of the embodients of the invention, as 2r described, a 4 microfarad capac.itor was used .in the device and 28 was connected in ser.ies wlth one of the fluorescent lam~s in a ! .. , ~L~3~i6 2 two lamp fixture. The lamps gave of~ 65 oot candles with a ~.80 3 amp and 120 volt power source and which created 88 watts o~
4 active power. Ilowever, there was 97.2 watts o~ apparent power.
The power factor was approximately 90.5% with an apparent 53%

6 savings in energy.
7 In another embodiment, a 5 microfarad capacitor was 8 used with an input power of 0080 amps and a 120 volts presenting 9 96 watts of active power. In this case, it was determined that there was a 100% power factor with no loss of powewr whatsoever ll but with a significant reduction in the amount of power used to 12 illuminate the lamps.
13 With a 2 microfarad capacitor, it was found generally 14 that the power was reduced about 50% although the lumen output was reduced approximately ~0%. Therefore, while the invention is 16 operable with capacitors having a capacitive value of less than 17 33 microfarads and greater than 6 microfarads it is preferable to 18 employ capacitors within the range of ~ to 5 microfarads.
l9 Thus, there has been illustrated and described a unique and novel means and method for reducing lumen output and power 21 ¦ consumption of a phosphor excitable lamp in a single lamp or 22 ¦ plural lamp arrangement without any appreciable effect on 23 efficiency of the lamp or power source therefor. Lhus, the 24 present invention fulfills all of the objects and advantages 25 ¦ sought therefore. It should be understood that many changes, 26 ¦ modifications, variations, and other uses and applications will 27 become apparent to those skilled in the art after considering 28 this specification and the accompanying drawings. Therefore, any 1 ~31B~
2 and all such chanqes, modif ication.s, and other uses which do not 3 depart from the splrit and scope of the inventlon are deemed to 4 be covered by the invention which is limited only by the follow-10 in cla ~ms.

1~

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-A means for use with and for limiting power consumption and lumen output of a conventional phosphor excitable lamp connected to a source of power for operation of same without any appreciable loss in efficiency of operation, said means comprising:
load limiting control means electrically connectable to one conductive end terminal of a phosphor excitable lamp and a conductive terminal in a socket and thereby effectively electrically interrupting the connection between the conductive end terminal of the lamp and terminal of the socket so as to be electrically interposed between said same conventional lamp and source of power in a series connection and so that said lamp remains in circuit relation to said source of power, said load limiting control means being selected so that the lumen output at the reduced level and the power consumption is reduced without substantially changing the voltage to the lamp and without any appreciable effect on the efficiency of the operation of said lamp or source of power.

The means for limiting power consumption and lumen output of Claim 1 further characterized in that the load limiting control means is operatively interposed between a conductive end terminal of said conventional phosphor excitable lamp and a socket which received the end terminal of said lamp.

The means for limiting power consumption and lumen output of Claim 2 further characterized in that the load limiting control means is a capacitive means.

The means for limiting power consumption and lumen output of Claim 3 further characterized in that said means for limiting power consumption and lumen output is capable of being electrically connected without connecting or disconnecting anything other than said lamp.

The means for limiting power consumption and lumen output of Claim 4 further characterized in that said means for limiting power consumption and lumen output consists essentially of conductive means and said capacitive means.

The means for limiting power consumption and lumen output of Claim 4 further characterized in that said capacitive means has a capacitive value from about eight microfarads to about fourteen microfarads.

The means for limiting power consumption and lumen output of Claim 4 further characterized in that said capacitive means has a value from about nine microfarads to about twelve microfarads.

The means for limiting power consumption and lumen output of Claim 4 further characterized in that said capacitive means comprises a first conductive element operatively engagable with the terminal on said lamp and a second conductive element electrically connectable to said source of power, an electrically non-conductive element separating said first and second conductive elements, and a capacitor means connected across said first and second conductive elements.

The means for limiting power consumption and lumen output of Claim 1 further characterized in that said means for limiting power consumption and lumen output is used to limit power consumption and lumen output of a plurality of phosphor excitable lamps in a series circuit arrangement of such lamps with respect to each other and with respect to a source of power for operation of said lamps, said means for limiting power consumption and lumen output being adapted to be interposed between one of the lamps and the source of power.

The means for limiting power consumption and lumen output of Claim 1 further characterized in that said lamp is a fluorescent lamp.

The means for limiting power consumption and lumen output of Claim 3 further characterized in that said control device is constructed so that it has a first section capable of fitting with respect to said socket and a second section offset from said first section and adapted to receive the end of said lamp which was received by said socket so that one end of said lamp is slightly offset from said socket.

The means for limiting power consumption and lumen out-put of Claim 3 further characterized in that said first section comprises a first conductive element electrically connectable to a conductive receptacle in said socket and said second section comprises a conductive receptacle to receive a conductive pin on said lamp and a capacitor means connected across said conductive element and conductive receptacle in said second section.

The means for limiting power consumption and lumen output of Claim 12 further characterized in that said first conductive element and said receptacle in said second section are electri-cally connected to said capacative means.

The means for limiting power consumption and lumen output of Claim 1 wherein the phosphor excitable lamp is removably retained in a fixture having a pair of spaced apart sockets with each socket having a conductive terminal and which sockets retain and connect conductive end terminals of the conventional phosphor excitable lamp, said a load limiting control means being operatively interposed between the conductive terminal in at least one of the sockets and the end terminal of the lamp at that socket and also retaining the lamp between the spaced apart sockets such that a circuit path originally between the conductive end terminal of the lamp and conductive terminal of that socket is no longer created directly between the conductive terminal of that socket and the end terminal of the lamp but rather through the load limiting control means and where said insertable means can be removed with the lamp remaining in or being reconnected between the pair of spaced apart sockets so that the lamp lumen output will increase to its original amount.

The means for limiting power consumption and lumen output of Claim 14 further characterized in that the load limiting control means comprises a capacitive means.

The means for limiting power consumption and correspondingly limiting lumen output of Claim 15 further characterized in that said capacitive means is effectively electrically interposed between a source of electrical power for said lamp and said lamp and said load limiting control. means is selected with a capaci-tive value so that the lumen output is reduced but with sub-stantially uniform lumen output at the reduced level and the power consumption is reduced without substantially changing the voltage to the lamp and without any appreciable effect on the efficiency of operation of said lamp or source of power.

The means for limiting power consumption and lumen output of Claim 15 further characterized in that said capacitive means comprises a first conductive element operatively engagable with the terminal on said lamp and a second conductive element electrically connectable to said conductive terminal of said socket, an electrically non-conductive element separating said first and second conductive elements, and a capacitor connected across said first and second conductive elements.

The means for limiting power consumption and lumen output of Claim 15 further characterized in that said capacitive means comprises:
(a) a first conductive element adapted to be engaged by and establish an electrical connection with an end terminal of said lamp, (b) a second conductive element adapted to engage and establish an electrical connection with a conductive terminal of said socket (c) an electrically non-conductive element between said first and second conductive elements electrically insulating same, and (d) a capacitor electrically connected to said first and second conductive elements such that an electrical circuit path is not established directly through the end terminal of said lamp and the conductive terminal of said socket when said device is used but rather through the end terminal of said lamp, said capacitor and the conductive terminal of said socket.

The means for limiting power consumption and lumen output of Claim 18 further characterized in that said conductive elements and said non-conductive element are closed within a housing.

The means for limiting power consumption and lumen output of Claim 19 further characterized in that a recess is formed in said housing and communicating with said first conductive element, and a prong is located on said housing and is in electrical contact with said second conductive element and adapted to extend into said socket.

The means for limiting power consumption and lumen output of Claim 14 further characterized in that said means is used to limit power consumption and lumen output of a plurality of phosphor excitable lamps in a series circuit arrangement of such lamps with respect to each other and with respect to a source of power for operation of said lamps, said means being adapted to be interposed between the conductive terminal of at least one of the sockets and the end terminal of the lamp at that socket.

The means for limiting power consumption and lumen output of Claim 21 further characterized in that said lamp is a fluorescent lamp.

The means for limiting power consumption and lumen output of Claim 14 further characterized in that said load limiting control device comprises a housing which has a first section capable of fitting in one of said sockets and a first conductive element connected to a conductive terminal in said socket, a second section of said housing capable of receiving an end of the lamp and having a second conductive element connected to a conductive end terminal of said lamp, and a load limiting electrical element in said housing and connected to the two conductive elements.

The load limiting means for limiting power consumption and lumen output of Claim 23 further characterized in that:
(a) said first conductive element is a pin adapted to fit within a conductive receptacle in said socket and establish electrical connection with said socket, (b) said second conductive element is a socket adapted to receive a pin on said lamp and establish electrical connection with a conductive terminal of said lamp, (c) an electrically conductive member between said first and second conductive elements electrically connecting same to said capacitive means.

, A method for limiting power consumption and lumen output of a phosphor excitable lamp connected to a source of power for operation of same without any appreciable loss in efficiency of operation, said method comprising:
a) disconnecting at least one end terminal of a lamp from a conductive terminal of a socket which received that lamp, b) electrically connecting a load limiting device to one terminal of said phosphor excitable lamp, c) connecting another portion of the load limiting device to the socket from which the lamp was removed so that a load limiting electrical element is electrically interposed between said lamp and source of power in a series connection, said element being selected with a value so that the lumen output is reduced but with substantially uniform lumen output at the reduced level, and the power consumption is reduced without substantially changing the voltage to the lamp and without any appreciable affect on the efficiency of operation of said lamp or source of power.

The method for limiting power consumption and lumen output of Claim 25 wherein said method comprising operatively physically interposing said load limiting control device between an electrically conductive end terminal of a conventional phosphor excitable lamp and an electrically conductive end terminal in said socket which receives the end terminal of said lamp, and thereby electrically interrupting the connection between the end terminal of the lamp and end terminal of the socket and thereby connecting said load limiting device to said one end terminal of said phosphor excitable lamp and said socket, said step of interposing effectively electrically interposes a capacitive element between said one end terminal of said phosphor excitable lamp and said socket, said step of interposing also effectively electrically interposes said capacitive element between said lamp and source of power in a series connection so that said same lamp remains in circuit relation to said source of power.

The method of limiting power consumption and lumen output of Claim 26 further characterized in that said method comprises physically interposing said capacitive element without connecting or disconnecting anything other than said lamp.

The method of Claim 27 further characterized in that said capacitive element has a capacitive value from about eight microfarads to about fourteen microfarads.

The method of Claim 27 further characterized in that said capacitive element has a capacitive value from about nine microfarads to about twelve microfarads.

The method for limiting power consumption and lumen output of Claim 25 further characterized in that said method limits power consumption and lumen output of a plurality of phosphor excitable lamps in a series circuit arrangement of such lamps with respect to each other and with respect to a source of power for operation of said lamps, said method comprising interposing the load limiting device between at least one of the lamps and the source of power.

The method of Claim 30 further characterized in that said lamp is a fluorescent lamp.