CA1261914A - Electric generator system for portable floodlighting equipment - Google Patents
Electric generator system for portable floodlighting equipmentInfo
- Publication number
- CA1261914A CA1261914A CA000530004A CA530004A CA1261914A CA 1261914 A CA1261914 A CA 1261914A CA 000530004 A CA000530004 A CA 000530004A CA 530004 A CA530004 A CA 530004A CA 1261914 A CA1261914 A CA 1261914A
- Authority
- CA
- Canada
- Prior art keywords
- windings
- lamps
- generator
- winding
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Control Of Eletrric Generators (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A power supply system for portable floodlighting equipment employing high-intensity electric discharge lamps comprises an alternating current generator having three or more independent armature windings, one for producing in-dependently current at a voltage sufficiently high for starting a discharge lamp in series with a capacitor. The windings are out of phase with one another and interference with the operation of the lamps energized by the separate and independent windings and electric apparatus energized by the standard voltage generator is effectively eliminated.
The use of the generator winding for starting and energizing the lamps eliminates the usual starting ballast and de-creases the weight and cost of the portable floodlighting unit.
A power supply system for portable floodlighting equipment employing high-intensity electric discharge lamps comprises an alternating current generator having three or more independent armature windings, one for producing in-dependently current at a voltage sufficiently high for starting a discharge lamp in series with a capacitor. The windings are out of phase with one another and interference with the operation of the lamps energized by the separate and independent windings and electric apparatus energized by the standard voltage generator is effectively eliminated.
The use of the generator winding for starting and energizing the lamps eliminates the usual starting ballast and de-creases the weight and cost of the portable floodlighting unit.
Description
1 This invention relates to alternating current power supplies for floodlighting e~uipment and the like which employ high-intensity gaseous electric discharge lamps.
Portable floodlighting is employed generally for il-luminating construction sites and the outdoor areas of other work and activity. T~e electric discharge lamp such as the high-intensity metal halide lamp requires a starting voltage substan-tially higher than the standard 120- and 240- volt domestic power supplies. It is the usual practice to provide trans-formers or ballasts for this purpose and also capacitors forlimiting the lamp current after starting. The ballasts add sub-stantial weight to the equipment, which is particularly undesir-able for portable equipment. Portable floodlighting units commonly comprise a trailer carrying an extendable mast on which a plurality of high-intensity electric discharge lamps are mounted and may be raised to elevated positions and an alter-nating current generator driven by a gasoline or diesel engine.
The generator is axranged to provide power for the floodlighting lamps and also for raising the mast and for power tools and other auxiliary electric equipment.
It is an object of the present invention to provide an improved power generation system for portable floodlighting units.
It is another object o~ -this invention to provide an improved alternating current generator system for supplying power both for the higher voltage starting of gaseous dis-charge lamps and for auxiliary equipment at standard voltages.
, '' : `
1 It is another object of this invention to provide an improved electric power system for floodlightingequipment and the like, including a single generator or supplying power at a plurality of different voltages.
It is a further object of ~his invention to provide an improved lighter weight power-generating system for portable floodlighting equipment and the like.
It is a Eurther object of this invention to provide an improved alternating current power supply for portable floodlighting units and the like, which requires less space, is lower in cost, .~nd requires fewer components.
51JMMP~RY OF THE I21VENTION
_ Briefly, the power supply system of this invention comprises an improJement on the alternating current generator of applicant~s Canadian patent ~,223,919 which issued July 7, 1987. The generator ls provided wqth a-plurality of independent sets of windings, each connected to supply a respective outlet. Current is supplied by one set of generator windings at a standard voltage, say 120 volts, and by two or more independent sets at a voltage sufficiently high for the starting of the electric discharge lamps, say 530 volts. When a plurality o~ lamps are employed, each lamp is connected across a respective independent 530-volt output. Capacitors, one in series with each respective lamp, act to limit the current flowing through each lamp after starting. The current o each set of windings is out of phase with that of the other.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a simpli~ied circuit diagram of the -.
, ~ ' .
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.:
1 power-generating system embodying the invention of the above iendified application;
Fig. 2 is a diagrammatic sectional end elevation view of the rotor and stator of a generator for use in the system of Fig. l;
Fig. 3 is a diagram illustrating the wave form and phase relationship of the current flowing in the two circuits of Fig. l;
Fig. 4 is a simplified circuit diagram of a power-generating system illustrating the present modification ofthe system of Fig. l; and Fig. 5 is a diagrammatic sectional end elevation view of the rotor and stator of a generator for use in the system of Fig. 4.
DETAILED DE~CRITION OF FIGS. 1,2 and 3 The electric generator system of this invention provides a main generator winding for supplying power to the motors for performing various functions iIl and around a portable floodlighting unit and a lamp current-supply winding for starting and energizing the high-intensity electric dis-charge lamps of the unit. This system as shown in Fig. 1 in-c1udes an alternating current generator 10 having a stator provided with one winding 11 for supplying power at standard voltage, say 120 and 240 volts, through main lines 12, 13 and 14 and a second and separated winding 15 of the coils of which have a sufficient number of turns for supplying power at a higher voltage, say 530 volts, for starting and ener-gizing high-intensity discharge lamps 16 through lines 17 and 18. Each of the lamps is connected in series with a capacitor .
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.
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1 19 between lines 17 and 18. Individual switches 20 are provided for selectively energizing the lamps, and a manual switch 21 is provided to connect the generator output to the lamp supply lines 17 and 18.
It has been Eound that b~ providing an alternator with two independent sets of windings, standard voltage and higher voltage supplies can be provided and operated to supply separate load systems without ob~ectionable interference with the operation of either system. The armature of a generator suitable for this purpose is illustrated in Fig. 2 in which the armature core, indicated at 22, is provided with forty-eight slots 23 in which the formed multiple-coil winding 11 and 15 are located and are indicated by light lines and heavy lines, respectively, which indicate the relative positions of the windings which are themselves located in the respective ones of the slots 23. Each formed winding is located with its sides in the two slots at the ends of the respective light and heavy line. These light and heavy lines repre-sent the end or return connections between the coils of the windings which have their current-generatings sides in the slots. The winding 11 are located in eight pairs of slots 23 in which the sides of the windings are located;
and, similarly, the windings 15 are located in four pairs of slots, each slot containing a respective side of a inding. There are two sets of each of the ~indings 11 and 15 which are indicated in the upper and lower halves, respectively, o~ the armature as shown in Fig. 2. The armature is used with a rotating field provided by a four-~:.
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.
. .
, : -:~ ,: .. ~, ., : .
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1 pole rotor 22a having the usual alternate North and South poles. The currents generated in windings on opposite sides of the stator are in phase; and these opposite wind-ings may be connected to the output either in series or in par~llel, the series connection being preferred as it pro-vides the higher voltaye which is the sum of the voltages of the opposite windings. Thus the standard voltage out-puts of the lines 12, 13 and 14 are indicated as connected to two windings in series with a center tap. The terminal connections of the coil ends (not shown) on the opposite side of the stator are made in accordance with the usual series or parallel connections of the windings; the return ends of the individual coils of the windings are, of course, positioned in the usual manner similar to the connections on the near side as shown.
During operation of the generator, the currents flowing in the two windings 11 and 15 are out of phase.
This phase relationship is indicated in Fig. 3 in which the curves of the two windings 11 and 15 are shown in time relationship. When the current in the winding 11 is at a maximum positive peak as indicated by the peak 24, the current in the winding 15 is a zero as indicated at 25.
The two windings are thus ninety degrees out of phase, or in quadrature. With the windings ou~ of phase, the effect of one circuit on the other during changing load condition has been found to be minimal during operation of a flood-lighting unit and other electric equipment associated . . ~.. .
. -~: ..
~` ~ ', ,. ~ -.
1 therewlth. By way of example an air compressor unit 26 indicated as comprising an electric motor 27 connected to drive an air compressor 28 may be connected across lines 13 and 14 to provide compressed air for raising a tele-scoping tower or the like.
DETAILED DESC~IPTION OF FIG~.4 and 5 Under some conditions of operation of the gener-ator system as described above, when the lamps are turned on and off, the transient conditions may affect the per-formance of the lamps. The modification of the circuitas illustrated in Fig. 4 is provided to eliminate the effects dut to transients. In this modification a gener-ator 30 is provided with a standard voltage winding 31 and four separate high voltage windings 32, 33, 34 and 35 are provided in the alternator armature for energizing lamps 36, 37, 38 and 39, respectively, upon operation oE switches 40, 41, 42 and 43, respectively. The lamps are connected n series with their respective windings through capacitors 44, 45, 46 and 47, respectively. Except for the arrange-ment of the windings, the generator 30 is of the same con-struction as generator 10 of Figs. 1 and 2. The windings 32, 33, 34 and 35 are located in respective armature slots to generate current at a phase difference of ninety degrees wlth respect to adjacent windings. The standard voltage winding 31 is connected to lines 4~, 49 and 50 which are ~rovided with switches 51, 52 and 53, respectively. Lines 49 and 50 are shown connected by switches 52 and 53 to .~ .
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1 supply current to an electric motor 54 for driving a com-pressor 55 which, for example, may be used for raising and lowering a telescoping tower or the li]ce. Fig. 5 which is a diagrammatic sectional view through the generator is essentially similar to the view of Fig. 2 except for the arrangement of the windings. The generator as illustrated comprises a stationary magnetic armature 56 and a rotor 57, the armature being provided with forty-eight slo~s 58.
The high voltage windings 32, 33, 34 and 35 are located in the outer two slots of each set of the four sets of twelve slots each about the periphery of the armature. The standard voltage windings 31 are loca-ted in the next four slots of each of the adjacent slots of twelve slots, this arrangement being such that the windings are ninety degrees out of phase. As a result the current in adjacent windings is ninety degrees out of phase and there is minimum interference between the adjacent windings during switching and changes of the load. Loads such as those present when fluorescent lights are being connected and disconnected may be varied without reducing or en-dangering the stable operation of the system. The system operates in a manner which permits the elimination of the ballast transformers normally provided in the fluorescent lamp circuits thereby saving weight, space, and cost and at the same time providing operation without loss in effi-ciency or in the effective starting of the lamps.
.
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Portable floodlighting is employed generally for il-luminating construction sites and the outdoor areas of other work and activity. T~e electric discharge lamp such as the high-intensity metal halide lamp requires a starting voltage substan-tially higher than the standard 120- and 240- volt domestic power supplies. It is the usual practice to provide trans-formers or ballasts for this purpose and also capacitors forlimiting the lamp current after starting. The ballasts add sub-stantial weight to the equipment, which is particularly undesir-able for portable equipment. Portable floodlighting units commonly comprise a trailer carrying an extendable mast on which a plurality of high-intensity electric discharge lamps are mounted and may be raised to elevated positions and an alter-nating current generator driven by a gasoline or diesel engine.
The generator is axranged to provide power for the floodlighting lamps and also for raising the mast and for power tools and other auxiliary electric equipment.
It is an object of the present invention to provide an improved power generation system for portable floodlighting units.
It is another object o~ -this invention to provide an improved alternating current generator system for supplying power both for the higher voltage starting of gaseous dis-charge lamps and for auxiliary equipment at standard voltages.
, '' : `
1 It is another object of this invention to provide an improved electric power system for floodlightingequipment and the like, including a single generator or supplying power at a plurality of different voltages.
It is a further object of ~his invention to provide an improved lighter weight power-generating system for portable floodlighting equipment and the like.
It is a Eurther object of this invention to provide an improved alternating current power supply for portable floodlighting units and the like, which requires less space, is lower in cost, .~nd requires fewer components.
51JMMP~RY OF THE I21VENTION
_ Briefly, the power supply system of this invention comprises an improJement on the alternating current generator of applicant~s Canadian patent ~,223,919 which issued July 7, 1987. The generator ls provided wqth a-plurality of independent sets of windings, each connected to supply a respective outlet. Current is supplied by one set of generator windings at a standard voltage, say 120 volts, and by two or more independent sets at a voltage sufficiently high for the starting of the electric discharge lamps, say 530 volts. When a plurality o~ lamps are employed, each lamp is connected across a respective independent 530-volt output. Capacitors, one in series with each respective lamp, act to limit the current flowing through each lamp after starting. The current o each set of windings is out of phase with that of the other.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a simpli~ied circuit diagram of the -.
, ~ ' .
'' ::
.:
1 power-generating system embodying the invention of the above iendified application;
Fig. 2 is a diagrammatic sectional end elevation view of the rotor and stator of a generator for use in the system of Fig. l;
Fig. 3 is a diagram illustrating the wave form and phase relationship of the current flowing in the two circuits of Fig. l;
Fig. 4 is a simplified circuit diagram of a power-generating system illustrating the present modification ofthe system of Fig. l; and Fig. 5 is a diagrammatic sectional end elevation view of the rotor and stator of a generator for use in the system of Fig. 4.
DETAILED DE~CRITION OF FIGS. 1,2 and 3 The electric generator system of this invention provides a main generator winding for supplying power to the motors for performing various functions iIl and around a portable floodlighting unit and a lamp current-supply winding for starting and energizing the high-intensity electric dis-charge lamps of the unit. This system as shown in Fig. 1 in-c1udes an alternating current generator 10 having a stator provided with one winding 11 for supplying power at standard voltage, say 120 and 240 volts, through main lines 12, 13 and 14 and a second and separated winding 15 of the coils of which have a sufficient number of turns for supplying power at a higher voltage, say 530 volts, for starting and ener-gizing high-intensity discharge lamps 16 through lines 17 and 18. Each of the lamps is connected in series with a capacitor .
'' : ., ,: :
.
' : -;
1 19 between lines 17 and 18. Individual switches 20 are provided for selectively energizing the lamps, and a manual switch 21 is provided to connect the generator output to the lamp supply lines 17 and 18.
It has been Eound that b~ providing an alternator with two independent sets of windings, standard voltage and higher voltage supplies can be provided and operated to supply separate load systems without ob~ectionable interference with the operation of either system. The armature of a generator suitable for this purpose is illustrated in Fig. 2 in which the armature core, indicated at 22, is provided with forty-eight slots 23 in which the formed multiple-coil winding 11 and 15 are located and are indicated by light lines and heavy lines, respectively, which indicate the relative positions of the windings which are themselves located in the respective ones of the slots 23. Each formed winding is located with its sides in the two slots at the ends of the respective light and heavy line. These light and heavy lines repre-sent the end or return connections between the coils of the windings which have their current-generatings sides in the slots. The winding 11 are located in eight pairs of slots 23 in which the sides of the windings are located;
and, similarly, the windings 15 are located in four pairs of slots, each slot containing a respective side of a inding. There are two sets of each of the ~indings 11 and 15 which are indicated in the upper and lower halves, respectively, o~ the armature as shown in Fig. 2. The armature is used with a rotating field provided by a four-~:.
:` : :
.
. .
, : -:~ ,: .. ~, ., : .
' 9~d~
1 pole rotor 22a having the usual alternate North and South poles. The currents generated in windings on opposite sides of the stator are in phase; and these opposite wind-ings may be connected to the output either in series or in par~llel, the series connection being preferred as it pro-vides the higher voltaye which is the sum of the voltages of the opposite windings. Thus the standard voltage out-puts of the lines 12, 13 and 14 are indicated as connected to two windings in series with a center tap. The terminal connections of the coil ends (not shown) on the opposite side of the stator are made in accordance with the usual series or parallel connections of the windings; the return ends of the individual coils of the windings are, of course, positioned in the usual manner similar to the connections on the near side as shown.
During operation of the generator, the currents flowing in the two windings 11 and 15 are out of phase.
This phase relationship is indicated in Fig. 3 in which the curves of the two windings 11 and 15 are shown in time relationship. When the current in the winding 11 is at a maximum positive peak as indicated by the peak 24, the current in the winding 15 is a zero as indicated at 25.
The two windings are thus ninety degrees out of phase, or in quadrature. With the windings ou~ of phase, the effect of one circuit on the other during changing load condition has been found to be minimal during operation of a flood-lighting unit and other electric equipment associated . . ~.. .
. -~: ..
~` ~ ', ,. ~ -.
1 therewlth. By way of example an air compressor unit 26 indicated as comprising an electric motor 27 connected to drive an air compressor 28 may be connected across lines 13 and 14 to provide compressed air for raising a tele-scoping tower or the like.
DETAILED DESC~IPTION OF FIG~.4 and 5 Under some conditions of operation of the gener-ator system as described above, when the lamps are turned on and off, the transient conditions may affect the per-formance of the lamps. The modification of the circuitas illustrated in Fig. 4 is provided to eliminate the effects dut to transients. In this modification a gener-ator 30 is provided with a standard voltage winding 31 and four separate high voltage windings 32, 33, 34 and 35 are provided in the alternator armature for energizing lamps 36, 37, 38 and 39, respectively, upon operation oE switches 40, 41, 42 and 43, respectively. The lamps are connected n series with their respective windings through capacitors 44, 45, 46 and 47, respectively. Except for the arrange-ment of the windings, the generator 30 is of the same con-struction as generator 10 of Figs. 1 and 2. The windings 32, 33, 34 and 35 are located in respective armature slots to generate current at a phase difference of ninety degrees wlth respect to adjacent windings. The standard voltage winding 31 is connected to lines 4~, 49 and 50 which are ~rovided with switches 51, 52 and 53, respectively. Lines 49 and 50 are shown connected by switches 52 and 53 to .~ .
, `~ ~;''~ . ,; . `
~" ~ , , L9~
1 supply current to an electric motor 54 for driving a com-pressor 55 which, for example, may be used for raising and lowering a telescoping tower or the li]ce. Fig. 5 which is a diagrammatic sectional view through the generator is essentially similar to the view of Fig. 2 except for the arrangement of the windings. The generator as illustrated comprises a stationary magnetic armature 56 and a rotor 57, the armature being provided with forty-eight slo~s 58.
The high voltage windings 32, 33, 34 and 35 are located in the outer two slots of each set of the four sets of twelve slots each about the periphery of the armature. The standard voltage windings 31 are loca-ted in the next four slots of each of the adjacent slots of twelve slots, this arrangement being such that the windings are ninety degrees out of phase. As a result the current in adjacent windings is ninety degrees out of phase and there is minimum interference between the adjacent windings during switching and changes of the load. Loads such as those present when fluorescent lights are being connected and disconnected may be varied without reducing or en-dangering the stable operation of the system. The system operates in a manner which permits the elimination of the ballast transformers normally provided in the fluorescent lamp circuits thereby saving weight, space, and cost and at the same time providing operation without loss in effi-ciency or in the effective starting of the lamps.
.
, ': , . :' ' ~
Claims (2)
1. A power generating system for portable floodlighting equipment and the like including a plurality of high intensity gaseous electric discharge lamps and an auxiliary electric motor-driven apparatus, an engine-driven generator for supplying alternating current to said lamps and to said auxiliary apparatus, said generator having a plurality of separate windings including a respective winding connected in a series circuit with each respective one of said lamps for supplying current at voltages sufficiently high for starting said lamps, a switch for each respective lamp circuit, and an additional separate winding connected to said motor-driven apparatus for supplying current at a lower voltage for energizing said auxiliary apparatus, said generator including a magnetic core having a multiplicity of slots for retaining the windings and wherein each of said separate windings is located in a different set of said slots, each of said respective windings generating alternating current at least approximately ninety degrees out of phase with respect to that of the other and with respect to the alternating current generated by said additional winding, a respective capacitor connected in series circuit with each of said respective windings and said respective lamps for limiting the current flowing through each said circuit when the respective lamp is conducting, the phase difference between the current flowing in said respective winding and the current flowing in said additional winding decreasing the likelihood of interference with the operation of the load on any one of said windings upon the occurrence of a change of load on another.
2. The invention set forth in claim 1 wherein said power generating system includes four of said lamps and four windings each connected in series with a respective one of said lamps and in series with a respective capacitor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/868,115 US4745340A (en) | 1983-07-14 | 1986-05-27 | Electric generator system for portable floodlighting equipment |
| US868,115 | 1986-05-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1261914A true CA1261914A (en) | 1989-09-26 |
Family
ID=25351108
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000530004A Expired CA1261914A (en) | 1986-05-27 | 1987-02-18 | Electric generator system for portable floodlighting equipment |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1261914A (en) |
-
1987
- 1987-02-18 CA CA000530004A patent/CA1261914A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
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