IL33589A - Portable handheld searchlight arrangement - Google Patents

Description

PORTABLE HANDHELD ARRANGEMENT BACKGROUND OF Field the Invention This invention relates to the searchlight ar and more particularly to an handheld searchlight Description of the Art In many applications it is desired to have a high electromagnetic radiation emission device for providing of a particular area with It be appreciated that such electromagnetic radiation may be in the visual portion of the radiation direct it may be in the infrared portion of the electromagnetic radiation spectrum for utilisation with infrared scopes or other red scanning or picture imaging Such of include police surveillance military utilizations both battle field as well as including and the search and rescue operations and many other types of In such portable searchlight whether in visual or infrared portions of the magnetic radiation the unit have certain performance characteristics in addition to illuminated or comparatively area to a lesser degree of To the best of applicant knowledge no prio art types of portable illumination devices have bee able to provide the That like utilising heated filaments sources of electromagnetic radiation generally such poor efficiency that the light intensity per unit weight particularly per unit weight of power source is comparatively on the other providing a high intensity light beam require comparatively large power sources generating the laser beam as as being Gas discharge lamps together with appropriate reflecting can provide the comparatively high intensity desired but to the be3t of knowledge no such gas discharge has been incorporated into a with a portable electric power supply therefor providing the different levels of energy by the gas discharge for successful BRIEF DESCRIPTION OF it is an object of invention herein to provide an improved portable light It is another object of invention to provide a handheld searchlight ment power supply circuitry It yet another object of invention The above and other objects of invention are according to one aspect by providing a case in which the structure for generating the beam of radiation is suitable parabolic reflector is mounted in the case and the parabolic reflector in common with such ventional parabolic an axis having at least one focal point thereof in close to the The source of electromagnetic in this embodiment of is a gas discharge Xenon lamp which is mounted on the axis of the To allow accurate positioning of the this embodiment of invention incorporates both radial adjustment means and axial The radial adjustment means allows movement of the Xenon lamp in radial directions from the axis of the parabolic The radial adjustment is generally utilised only once for an initial factory setting to allow precise alignment of the Xenon lamp on the of the parabolic An means is also provided moving the Xenon lamp to positions closer to the reflector and further from the reflector by the preferred focal point thereof as well as allowing positioning of the Xenon lamp directly on the focal It is conventional to allow positioning of the course of electromagnetic radiation directly on the focal point so that all the electromagnetic radiation from the reflector is generally directions parallel to the axis When the lamp is positioned off focal but still on the axis of the illumination emitted by the reflector is still substantially symmetrical about the axis but will not substantially parallel to the axis That some illumination will to diverge the to allow a wider area of illumination though at less It will appreciated that comparatively small along the axis of the reflector by the source of electromagnetic radiation the focal point can provide large angular In order to provide precise control of the emitted applicants prefer to include a shield comprising a cylindrical tube around the source of magnetic The light shield intercepts the radiation by the that not reflected by the reflector and thus prevents the tively angular dispersion thereof and electromagnetic radiation the desired path substantially parallel to the of the The preferred of invention also includes a portable source of electric energy such as a battery together with circuitry necessary for operation of the electromagnetic radiation emission V7hen a Xenon lamp or other gas discharge lamp is utilised as the source of electromagnetic radiation such as electromagnetic radiation the visual portion of the electromagnetic radiation then the circuitry must include not only the necessary elements for supplying different levels of electrical energy but also a means for switching from one level to the other as necessary for That there may be considered to be four separate levels of electrical necessar for operation and the appropriate switching arrangements When the Xenon lamp is first started it requires a comparatively high voltage order to ionise the gas between the electrodes of the to establish conduction prefers that this be an nating current It is next included a first source direct current electrical energy having a high voltage value that is utilised to sustain the arc the electrodes through the gas that has established b the alternating current The high voltage may be decreased to an intermediate direct current level that provides sufficient power dissipation in the arc to initially heat cathode of the source of radiation so that the electric emission is sufficient to establish a high enough current density for maintaining the A third or comparatively low voltage direct current which is the normal operating voltage can then be applied to maintain satisfactory operation of the gas discharge lamp under the stable operating conditions priate switching between the four different electrical energy requirements is also In various embodiments of invention described different methods for generating the four different electrical energy requirements and fo switching therebetween are shown and in each the mental source of electrical energy a voltage rating equivalent to the lowest or the steady state BRIEF DESCRIPTION OF THE Figure 1 is a perspective view of one e of invention Figure 2 is a section along the line of figure Figure 3 illustrates another axial adjustment arrangement useful in the practice of invention Figure is an end the of invention shown in Figure Figure illustrates in schematic form a circuit useful in the practice of invention Figure 6 illustrates in another circuit useful in the practice of invention Figure 7 in another circuit useful in the practice of invention Figure 8 illustrates another circuit useful in the practice of invention Figure 9 in block diagram the circuitry useful in DESCRIPTION THE PREFERRED Before detailing a description of invention applicants wish to point out that the specific structure selected for utilization in the description of the preferred embodiments to illustrate e e m e n h a a c 314 of equivalent structures for performing the same or stantially identical while applicants their invention as practiced with a Xenon gas discharge it appreciated that other sources of electromagnetic radiation including those in the ultraviolet or infrared portions of the may be and can equally well be invention applicants have selected inclusion in this description a source of electrical energy in 12 to direct current range since this is a conventional and readily available it will be many other voltage ranges for the source of electrical energy raay be selected depending upon the particular Xenon lamp to above as source of electromagnetic radiation of put out a high degree visual electromagnetic radiation as well as electromagnetic radiation in the infrared portion of the electromagnetic radiation it is desired to use a Xenon lamp to provide infrared radiation without visual radiation such as way be required in some military operations and suitable filters nay be placed over the end of the to transmission of visual in those applications of only ultraviolet light raay bo such as those applications where fluorescence of various is to be either a suitable ultraviolet source of electromagnetic radiation may be utilised additional filters for eliminating visual or other of electromagnetic may be Referring now to Figures 1 2 and 4 there illustrated a proferred form of applicants1 invention of an improved portable searchlight generally designated As there is provided a 12 in which there is a source of electromagnetic radiation The source of electromagnetic radiation 14 is adapted to an electromagnetic radiation having energy in a preselected within the definition of the the source of magnetic radiation 14 for purposes of considered a Xenon gas discharge such the Xenon lamp 14 emits electromagnetic radiation having energy in both visual portions of electromagnetic radiation spectrum and also the infrared portion of the electromagnetic radiation A lens means be mounted on the case means though a lens is not necessary for proper operation of many embodiments of If the lens means 16 is included it may be a band pass filter type lens in fo only infrared electroraagnetic radiation is mitted therethrough and visual energy is stopped from transmission the lens means may transmit electromagnetic radiation in the visual portion of electromagnetic radiation the lens means 16 may any desired transmission istics as rejuired for particular A re means 18 is mounted inside the case means 12 and it receives a first portion of electromagnetic radiation emitted from the source of electromagnetic radiation first portion of electromagnetic radiation reflector IS is generally designated by the arrow 20 and afte striking the reflecto means 18 it reflected therefrom in a direction indicated by arrow 22 for the preferred embodiment of invention wherein the reflector means 18 is a parabolic the firs direction of distribution pattern indicated by the arrow 22 is parallel to the axis of the generally parabolic reflector Such electromagnetic radiation passes through the lens means if such is to the extent of the transmission characteristics to regions external the portable searchlight second of the electromagnetic radiation the electromagnetic radiation source 14 is designated by the arrow 24 and this portion magnetic radiation 24 is not intercepted by the reflector because of the relationship in order to concentrate electromagnetic radiation emitted by the portable searchlight 10 into a desired applicants prefer to include a shield means that intercepts such second portion of radiation 24 to prevent it from a wide dispersion or distribution pattern and substantially allow only the transmission of radiation in a direction indicated by the A mounting means 23 comprising flat mounting portion 30 and a rear portion 32 is for retaining the source of electromagnetic radiation 14 in a ositio respect to the parabolic reflector means An adjustment means 34 is provided as cooperatively coacting with the mounting means 23 to allow the source of electromagnetic radiation 14 into a plurality of positions with respect to the reflector means A handle means 36 coupled to the case 12 to allow convenient carrying the portable searchlight 10 if the handle means 3G may include therein the electrical circuitry generally indicated at 38 interior the handle 36 as well as a source of electrical energy generally indicated at 40 which also may be included within the as described below in greater detailp As shown more clearly on Figure the reflector means as noted in the preferred embodiment of is a parabolic has an axis 42 and at least one focal point of the parabolic reflector 13 is at the point indicated at When the source of electromagnetic radiation 14 is positioned exactly at the focal point 44 light therefrom as indicated by the portion of electromagnetic radiatio at the arrow 20 strikes the parabolic reflector 18 and is reflected therefrom in the direction by the arrow 22 which is parallel to the axis Thus a searchlight effect is provided by the reflector The electromagnetic radiation in a second portion 24 emitted from the of electromagnetic radiation 14 strikes the light 26 and is prevented from being emitted from the portable searchlight 12 at comparatively wide angular dispersion patterns from the desired direction parallel to the axis in some embodiments of invention it may be desired to have a divergence to the light emitted om the portable searchlight 10 such that it is not all concentrated substantially in directions parallel to the axis 42 as indicated by the arrow In those of invention an means as indicated by rear adjustment means 34 is provided to move the source of electromagnetic radiatio 14 along the axis 42 to positions closer to the reflector 18 than the focal point 44 and further from reflector 13 than the focal point 44 on the axis of changes the reflective characteristics of the light source 14 reflector means 18 combination such the electromagnetic radiation reflected by the reflector means will not substantially parallel to the axis at a given distance from the portable searchlight 10 at maximum intensity the light source 14 is at the focal point 44 and the electromagnetic radiation is substantially parallel to By moving the light source 14 along the axis 42 but from the focal point 44 an angular dispersion in a and selected angular pattern distribution is obtained so that a greater area is covered by the light emitted from the portable searchlight 10 at a lower intensity per unit area The axial adjustment obtained by rotating the knob which is retained by retainer ring 48 mounted on case 12 at the 50 The adjustment knob 46 threadingly a electric screw means 52 that is coupled to therear mounting means 32 in this embodiment of is in the form of a tubular friction clip 54 in which the dielectric screw means 52 is coupled by a screw 56 at the roar end thereof and a rear contact 60 of the source of electromagnetic radiation 14 is held tightly at a forward end 62 of the friction clip 54 by screw rotation of the knob 46 moves the dielectric 52 along the axis 42 in the directions indicated by the 64 to move the center of the source of radiation to positions closer to or further away the reflector 18 than the focal point The forward contact of the source of radiation 14 is frictionally retained for axial sliding movement therein by the forward mounting means described below in greater It will be appreciated that a could equally well be provided for the axial movement of the source of electromagnetic radiation One such embodiment of invention generally designated 70 is in Figure 3 there is provided a case means which may be generally similar to the case means 12 sham in Figure 1 in which a rear mounting means 72 provided for axial adjustmen a source of magnetic radiation 74 along an axis 76 of a generally parabolic reflector means which may be similar to the parabolic reflector 13 shown in Figure Λ clip 80 which may be similar the 54 shown in Figure 2 provided for frictionally engaging a rear contact of the source of electromagnetic radiation dielectric rod means 84 is retained by screw means 86 o the rear portion the clip SO and mounted b pin means 90 in a lever The lever 92 projects from the case means 12 and has a handle portion 94 which may be moved in the directions indicated by the arrow 96 to move the source of electroraagnetic radiation 74 in the directions indicated by the arrow The lever means 92 is pivoted on the bracket 100 by pivot pin weans The handle 94 guided in a slot of a guide means 103 that is coupled to a case means extension It will be appreciated that many variations of the lever adjustment for providing axial movement of the source electromagnetic radiation as indicated in Figure 3 or the rotary means for providing the axial movement of the source of electromagnetic radiation 14 may be provided achieve the desired functional result within inventio of a ial positioning of the source of magnetic radiation in desired locations with respect to the reflector means Xn the preferred embodiment of invention the spring clip 32 is electrically conductive and an electrical lead 112 that is connected to the electrical circuit 38 supplies electrical energy by the connectio at scre means to the clip 32 to make electrical contact with the rear contact of the source of magnetic radiation conventional lamp lead means 114 may be provided on the source of electromagnetic radiation 14 and if so it may be suitably electrically connected to the clip 54 as in the preferred ment of electrical connection to th source o electromagnetic radiation through the rear means 32 is provided by the electrically ductive clip The parabloic reflector 18 has walls 116 defining an aperture 118 therethrough in axial regions thereof to allow the insertion of the rear mounting means A dielectric shield means 120 may be included to prevent arcing to the case means 12 from the clip in the pivotal axial adjustment arrangement shown Figure 3 a planer dielectric shield 122 may be utilized for the same The adjustment means 28 includes the forward means The forward adjustment means 30 provides for a radial alignment of the source of electromagnetic radiation 14 and is generally only utilized once as a factory setting to align the source of electromagnetic radiation 14 properly on the axis 42 of the parabolic reflector That axis alignment of the source of electromagnetic radiation 14 result in a pattern of electromagnetic radiation emission the portable searchlight Since this is generally not the radial adjustment provided by the forward mounting arrangement 30 may be utilized to position the electromagnetic radiation source 14 This is shown more clearly in Figure 4 which is a front view of the embodiment of invention shown in Figures 1 and Th radial adjustment means comprising the forward mounting means 30 has a spring mounted leg 130 mounted by spring means 132 on the case means A shoe portion 132 thereof is coupled by screw 135 to the case means 12 to provide electrical and thermal conduction paths from the source 14 to the case means A pair of screw mounted legs 134 and 136 as may be are supported by fixed shoe portions and are mounted by adjustment screw 138 and ment of the adjustment screw means 133 and 140 moves source of electromagnetic radiation 140 generally in plane perpendicular the axis It will be appreciated that required alignment movements are generally small and thus though the source of electromagnetic radiation 14 generally pivots about the rear contact 60 maintained in the rear spring clip 54 it is generally in such a perpendicular to the axis 42 until it is in Figure 4 the two screw mounted leg means and 136 generally come together to form a forward spring clip means 142 for supporting frictionally the forward contact 66 of the of electromagnetic The spring clip 42 thus frictionall engages the contact 66 but allows axial movement of the forward contact 66 therein during axial adjustment of the electromagnetic radiation It will be appreciated one o 134 or 136 may be made cally conductive and the forward contact 66 for be provided as the ground connection for electrical described If an appropriate contact lead may be suitably utilised as desired om the forward contact Λ rim means 150 is shown Figure 2 for supporting the lens means rim means 150 is attached by a plurality of 152 to the case means can be seen Figure 2 source means 26 generally comprises a tubular member of a opaque material to prevent the transmission of any electromagnetic radiation second portion 24 The cylindrical light shield means 26 is generally coaxially mounted with the axis 42 of the parabolic reflecto the preferred embodiment of the le 134 and 136 radial adjust 130 substantially apart as applicants have found that this provides a good on the radial 6f the source of electromagnetic radiation noted the preferred of invention includes a source of electrical energy and appropriate circuitr for startin operating the source of electromagnetic radiation It will be appreciated sources providing electrical energy have heretofore been utilised in the past in have not proven satisfactory because of the inability to utilise for all functions the portablo source of electrical such as a that is voltage rated for the normal operating voltage o the gas discharge lamp when such is utilised as the source of electromagnetic on tho other allows utilisation of a source of electrical energy at the voltage rating for normal operation of the lamp for all other functions required for proper operation of the searchlight Figure illustrates a block diagram form of the circuitry and switching necessary for operation o improved portable As shown in Figure 9 a source of electromagnetic radiation such as the 314 source of electromagnetic radiation 14 is powered by an appropriate electrical circuit having its electrical energy In order to establish the emission of electromagnetic radiation from the source of magnetic radiation 14 it is first necessary to provide a electrical potential across the lamp the rear contacts 60 to the contacts In this as shown on the block diagram Figure the rear contact 60 is Generally a high voltage alternating current potential is utilised to provide the initial ionization of the Xenon gas between the electrodes in the source of electromagnetic radiation 14 to the initial is provided a high voltage source 160 that is connected into circuit by a first switch After the initial arc is established switch 162 is open and switch 164 is closed to bring in a high voltage power 166 to sustain the arc across the electrodes in the source electromagnetic radiation Then 16 is opened and switch is closed to bring in an voltage level power 160 to provide adequate power dissipation in the arc and heating of the cathode electrode in the source of electromagnetic 14 to establish a sufficient current density emission to sustain the Then the switch 167 is opened and the switch 170 be closed to bring in the voltage 172 which is utilised for sustaining the steady state arc across the lamp It will be appreciated that the energy provided by the high voltage source high voltage source 166 and intermediate voltage source 168 are transient in nature and the low voltage source 31 172 is utilised for steady state It will further be appreciated that switching must instantaneous in that each successive change of voltage occur in a manner such that there is no interruption of power being continuously applied to the it is preferred that switching take place to the largest extent possible during operation of the portable searchlight according to In the past electrical circuits utilised operating gas discharge lamps have generally til an power source as a source of electrical The was converted to with a voltage rating up or the voltage rating required for a steady state The high voltage source was generally established from tho source utilising a transformer to the potential to the required The high voltage was then provided by the direct voltage the comparatively high voltage source operating through a conventional ballas is a transient condition between this high voltage sustaining the initial arc and the low voltage requirement that was taken into account by utilising ballast resistor to set proper across As the voltage drop across the lamp decreased the current increased to tho level of stable operation and thus provided switching indicated b switches and on the other utilises a of electrical energy such as a battery equivalent to that necessary for the low voltage supplied by voltage source 172 without utilising a comparatively high level voltage Figure illustrates one of an electrical circuit and source of electrical energy for utilisation in the practice and is generally designated In this circuit the Xenon lamp is generally designated 210 and may be similar to the 14 described The circuit ie conditioned for proper operation by a closing of the switch 212 in direction indicated by the arrow the switch is in this is the opposite position to that illustrated in Figure which may be referred to as a reset the direct curren source of electrical energy 216 for be a olt and is the potential required for steady state operation of the lamp and the potential of the small battery 218 for may be a battery applied across capacitors 220 and 222 are charged to the sura of the batteries 213 or approximately 18 The resistor 224 acts as a current limiting resistor during this initial charging It will be appreciated that is additionally charged through diode 226 after switch 212 moved to the run position indicated by the arrow 228 and in the position indicated on Figure prevents discharging of capacitor when in run position shown capacitor 220 222 are connected in a series across the lam The lamp is then started by depressing switch This is depressed in the direction indicated by the arrow 232 to close the indicated In this start position the capacitor 220 and 222 are connected in series with the source of electrical energy plus side of capacitor 222 is at potential of four times the voltage of the source of electrical energy for can be is applied across the and discharge is prevented by diodes and The electrical chopper 23G is activated by cation of voltago the source of electrical voltage through resistor the supply voltage provided by source of electrical energy is also applied to the primary 240 of a transformer 242 which may be as through resisto The electrical chopper 236 operating cooperatively with capacitor 246 converts the direct current signal thus applied at the primary 240 of the 2 to an alternating current which by inductive coupling of the 242 240 generates a high voltage nating current on the order for potential is across the primary 240 of transformer 250 and also across spark gap The spark gap 252 operates as a voltage breakdown gap and sequentially conducts and discharges capacitor 255 many times during each positive and negative phase of the alternating current Each discharge across the spark gap 252 is a short duration such as form equivalent to a frequency on the order of one megacycle or Thu a high high frequency signal is impressed on the primary 240 of the transformer 250 and transfers by the transformer 250 lamp and ionisaticn of the gas occurs to establish an initial electrode of the lamp Once the arc is established then capacitors 220 and 222 discharge as high voltage direct current signal across the lamp 210 to sustain this When the switch 230 is depressed in the direction indicated by the arrow battery 218 is connected in series with the source of electrical energy For the values cited this provides a voltage of 10 or one and times the voltage the rating of the source of electrical energy 21G and is impressed across the lamp 210 through resisto diode 232 and resistor there will be no curren from the battery 218 until the on the 210 side the diode 232 below the potential on the battery side thereof to allow diode 232 to become forward biased and thus This only occurs after capac to 220 and 222 have discharged through the Then the current from the source of direct current electrical energy 216 and the battery 218 provide the intermediate direct voltage cignal required to sustain the energy for current density to sustain the heating of the It will be appreciated that resistors 254 and 256 act as ballast resistors and provide a voltage drop that increases as the lamp 210 current As lamp 210 current approaches the the voltage drop across these resistors 254 and 256 is approximately equivalent to that applied by the battory 218 and the voltage then is impressed across the lamp 210 in substantial 214 equivalence to the supply of voltage by the source of electrical energy return o the 230 to the position in Figure the battery electrical S chopper 236 and transformer 242 from the circuitry between the of electrical energy 216 and 210 thereby transferring of the lamp 210 to the steady state condition from source of electrical energy In this embodiment the lamp be turned 10 off by temporarily interrupting circuit such as b depressing switch Figure illustrates another in diagram useful in the practice of invention shown on Figure G this generally 15 nated is provided with a switch 272 which is movable from the run position shown in Figure ΰ indicated by the arrow 274 to a start position which is the opposite position as indicated by the arrow The switch 272 is a double double throw 20 it is depressed throug the start position as indicated by arrow 276 the supply 270 which may bo similar to the 216 described is connected to the electrical chopper the battery 232 and the primary 20 of the transformer The chopper in 5 conjunction the capacitor 283 converts the direct current signal applied to the primary 284 of transformer to an alternating current potential and by mutual inductance and direct connection of the primary 204 to a secondary 290 of the transformer a high voltage 0 nating current signal is established across the transformer 314 as described resonant appear as relatively high voltage across capacitor 283 frequency generated by the electrical chopper These high voltage spike3 are rectified by diode through resistor 294 to charge capacitor 296 to a value sufficient to supply the required high voltage as the source of high voltage shown in Figure the charging of capacito 296 sufficiently loads the transformer so that the gain thereof is insufficient to produce a voltage potential great enough to generate an arc across the spark gap as capacitor approaches its maximum charge the load on 286 is reduced and the output voltage increases until the breakdown voltage of spark 293 is reached and the spark gap described above in connection with the embodiment shown in Figure this provides the high voltage current signal to the larap 210 through the transformer 300 which operates in a similar to the transformer 250 described The relatively high voltage in capacitor is the discharged across the lamp 210 to supply the transient high voltage signal After the capacitor 296 discharges below the voltage level established by the battery together with the voltage value of source electrical energy in series diodes 302 forward biased and conducts and the voltage of the source electrical energy 273 and the battery 202 impressed across the lamp 210 through resistor 304 to provide the intermediate level voltage signal required as described The 314 resistor 304 acts in a similar to a ballast as the current through the 210 increases to that provided in stable voltage drop across resistor 304 increases until the voltage impressed across the lamp 210 is equal to that the source electrical energy 278 Switch 272 is then moved to the run position indicated on Figure 6 indicated by the arrow hich provides the source of the electrical energy 270 directly the 210 for stable may be turned by momentarily opening the circuit at the switch will be appreciated that with the switch 272 in position for run as indicated in the battery 232 is recharged from the source electrical energy 278 through the resistors 306 and 303 as well as the coil of the electrical chopper Figure 7 illustrates another embodiment of a circuit useful in the practice of invention generally designated In the circuit 320 it is virtually identical to the circuit shown in Figure 6 except that it is a positively grounded circuit to eliminate the need a special shielded wire to the front end of the lamp 14 in Figure 1 and allow direct grounding of the forward end through contact 66 and the forward mounting means That the case 12 may be the ground for the forward mounting support comprising the legs 134 or or any of may be electrically ductive to provide the operation o this circuit 320 as shown operation of the lamp 210 operates in the manner completely analogous to that described 314 in connectio with the circuit shown in Figure there is shown another positively grounded circuit generally designated 330 useful in the practice of The embodiment of circuitry 330 is virtually the same the in Figures 6 and in thi embodiment the outpu of the transformer has been boosted by increasing the potential applied to the primary thereof by including the battery as part of the charging voltage this drained the tively small ampere hour of the conventional battery utilised battery and hence a third battery 332 for with the values of the source of electrical energy being 12 volts and the value of battery being 6 battery 332 could be on the order of Also as can be see the resistor 338 was nected to the terminal 340 o the switch 342 so when the switch 342 was in the run position as illustrated on Figure 8 the chopper 344 was isolated when the switch 342 was in the run Figure 10 illustrates another embodiment a circuit that have found useful in the practice of their inventio to achieve the functions of starting and operating the lamp generally designated 402 may be similar to lamp 14 described this circuit 400 provides the four functions of high voltage high voltage intermediate voltage and low level and the appropriate switching automatically 314 on Figure 10 the switch 404 supplies the negative 406 of a battery 403 to tho lamp with the switch 404 12 volts impressed c the transistors 410 and which transistors but arc not through the primaries 414 and The negative voltage is thus impressed on the base terminal 410a and 412a on transistors 410 and through resistor 420 and the primary portion 422 of the transformer each of the transistors 410 and 412 start to since the characteristics of the transistors 410 and 412 are not perfectly transistor actually starts to conduct before the other thereby resulting in an oscillatory condition of conduction between the two wherein current tends flow alternately through the circuits of transistors 410 and The inductive through portion 422a with portion 414a of the primary 422 of the transformer 413 and tho inductive coupling between portions 422b and portion 416 of the of transformer 418 drives the base as 410a and 412a of first one of the two transistors to conduct negitive and the other transistor An oscillating is thus set in When transisto 410 and portion 422a conduct an electromotive force is set up in 414 and 416 which drives the base 410 positiv and the base of 412 transistor 410 ceases to conduct transistor 402 conducts so the current through portion 422b and stops through portion 422a of the primary 422 of transformer 314 inductive coupling at two portions 414 and 416 results in a reversal of this The oscillation thus up in portions 422a and portions 422b are impressed secondary 424 of the It will be appreciated that the circuitry generally designated 411 thus far described for the circuit 400 prises inverter portion and will be appreciated that other transformer coupled converter circuits are and could be utilised to supply the output requirements as obtained from the secondary The open circuit voltage of 424 is on the order volts RMS when the voltage across the portions 422a and 422b is 12 The core of the 418 and the of windings of both the primary 422 and secondary 424 are such that the voltage across 424 be about 2 volts EMS with a load induced current of 7 amperes the circuit of the secondary The voltage of the secondary 424 is rectified by a rectifier bridge This rectifier voltage is then superimposed upon the source by direct connection of a negative from the battery 403 to the point 42S of the rectifier bridge sum of those voltages is then impressed across the lamp 402 through the secondary 430 of transformer voltage from the secondary 424 of 418 is also impressed across the primary of transformer such as another transformer inductive coupling between the primary and the secondar of trans ormer results in approximately volts being developed across transformer 434 with 20 30 volts input from the secondary 434 of transformer This volts is impressed on spark gap 440 through the primary 442 of transformer By inductive coupling this voltage is transferred to the secondary 430 of the transformer 432 and thus is impressed across lamp The volts across the lamp 402 ionizes the the electrodes of the lamp causes it to As the lamp starts to conduct of voltage of the secondary 424 of transformer 418 drops to 2 volts superimposed results in 14 volts being impressed across the lamp 402 and the lamp 402 continues to conduct and operate in its normal Although the primary 436 of the transformer is still connected to the secondary 424 of transformer the output voltage of secondary 42 is only 2 This 2 volts is not sufficient to result in a high voltage output from transformer spark gap 440 does not conduct to all intents and the output circuit of 434 is open resulting in high impedance across the 436 of transformer fore transformer 434 does not load the 424 of transformer The lamp may be turned merely by the circuit here at switch Figure 11 illustrates yet another circuit generally designated 500 that is similar in operation to the circuitry in Figure in the embodiment of the circuit 500 shown on Figure there is provided structure similar to the embodiment of applicants1 invention shown in Figure and in which the circuit is made operable by closing switch An electrical chopper 502 operated through start switch 504 is utilised to provide the alternating current the direct current source as applicable here in the starting of the circuit designated 500 in a manner similar to that After the initial start of the 506 has been the start switch 504 is released and the electrical chopper 502 is cut out of the circuit and the inverter stage generally designated 508 which is tc inverter stage 411 described in the embodiment of invention shown in Figure 10 is utilised to supply the other electrical power requirements during transition operation of the lamp 506 in a manner identical to that described above for the circuit The lam is turned off by opening switch This concludes the description of invention and improved portable handheld searchlight can be seen from the above description the accompanying applicants have provided a conveniently searchlight uniquely operates all functions of a gas discharge lamp with a voltage included therein that is individually no greater than the voltage for steady state claimed now and to bo by t e United insufficientOCRQuality

Claims (1)

1. An Improved portable searchlight arrangement in A source of radiation having forward electrode and a eleotrode spaced from said forward electrode emitting tromagnetic radiation in a preselected and said emitted tromagnetic radiation having energy in reflector means adjacent said source of electromagnetic radiation fo receiving first portion of electromagnetic radiation in preselected distribution and reflectin said portion of said radiation for receivin a first portion of said electromagnetic in said preselected distributio and reflecting said first portion of said radiation in a first directional mounting means supporting said source of electromagnetic at preselected positions in apart relationship to said reflecto and said mounting means an electrically conductive forward clip means coupled in cally conductive contact with said forward electrode of said source of magnetic radiation and a electrically conductive rear clip means coupled in electrically conductive contact with said rear electrode of said source of electromagnetic adjacent said source of electromagnetic radiation for intercepting a second portion of said electromagnetic radiation in said preselected distribution to prevent said second portion of electromagnetic radiation from emission in a second preseleoted directional pattern different from said first preselected directional patterns adjustment means o mounting means said source of electromagnetic radiation into said preselected shield support means for supporting said shield for ment with said soured of electromagnetic radiation for the condition of movement of said source of electromagnetic radiation portions of preselected and source of electromagnetic radiation moveable respect to said shield means for movement of said source of electromagnetic radiation in said first portions of said positional energizin means connected to said forward spring clip means and to said rear clip means for supplying energy to said source of magnetic An improved portable searchlight arrangement according to claim in combinations source o electromagnetic radiation comprising a gas discharge lamp means having a forward electrode and rear electrode spaced from said electrode for emitting electromagnetic radiation in a selected and said emitted electromagnetic radiation having energy in a preselected and said preselected bandwidth of electromagnetic radiatio is in the visible portion of the electromagnetic radiation reflector means adjacent said source of electromagnetic radiation for receiving a first portion of said electromagnetic radiation in distribution and reflecting first portion of magnetic radiation therefrom in a first preselected directiona mounting means for supporting said source of electromagnetic radiation at preselected positions in spaced apar relationshi to said reflector and said mounting means comprisin electrically conductive forward clip means in electrically conductive contact with forward electrode of source of electromagnetic and an electrically conductive rear clip means coupled in cally conductive contact with said rear electrode of said source of electromagnetic at least one of said forward clip means and said rear means comprising a spring clip means for frictlonal retentio of said source of electromagnetic radiation for condition of of said source of electromagnetic radiation in first portions of preaiected adjustment on mounting means fo moving said of electromagnetic radiation into said preselected posltionsf shield means adjacent source of electromagnetic radiation intercepting a second portion of said electromagnetic radiation preselected distribution to prevent said second portion of magnetic radiation from emission in a second preselected directional pattern different from said first preselected directional shield support means for supporting said shield means for movement tilth said source of electromagnetic radiation fo the condition of movement of said source of electromagnetic radiation in second portions of said preselected positions said source of electromagnetic radiation moveable with respect to said shield means for movement of said source of electromagnetic radiation in said first portion of said preselected and energizing means connected to said clip means an to said rea clip means for supplyin to said source of magnetic and said energizing means further alternating curren means applying an alternating current establishing an electrically conductive path therethrough to generate an electrical arc firs direct current moans for applying a first direct current signal having sufficient to sustain arc across second direct current means for applying a direct current signal to said gas discharge lam for providin a selected dissipation therein for sustaining said third direct current means supplying third direct current signal less said first and said second direct current signals across said gas for providin thermal energy for electron of said gas discharge for stable and for selectively switching between said signal said first signal said second signal means and said signal improved portabl searchlight arrangement according to 1 a source o electromagnetic radiation a forward electrode and rear electrode spaced from said fonrard electrode for electromagnetic radiation in a and said emitted electromagnetic radiation having energy in a preselected reflector adjacent said of electromagnetic radiation for receiving a first portion of said electromagnetic radiation in said preselected distribution and reflecting said first portion of said electromagnetic rodlatio in a first preselected directional mounting supporting said of electromagnetic at preselected in spaced apart relationship to reflector and said counting means an electrically conductive forward clip coupled electrically conductive contact with said electrode of said source of radiationj an electrically conductive rear clip means coupled in electrically conductive contact with said rea of said source of electromagnetic radiationj and at least One of said forward cli and said rear clip means comprising spring clip for frictional retention of said source of electromagnetic radiation for the condition of men of said source of electromagnetic radiation in first portions of said preselected positions means on said mounting for moving said source of electromagnetic radiatio into said preselected positional shield means adjacent said of electromagnetic radiation fo intercepting a portion of said electromagnetic radiation in preselected distribution to prevent said second portion of electromagnetic radiation from emissio in a second preselected directional pattern different from said first preselected directional support means fo supporting said shield means fo movement with said source of electromagnetic radiation for tho condition of movement of said source of electromagnetic radiation second portion of selected and said source of electromagnetic radiation moveable with respect to said shield means for movement of said source of magnetic radiation in said first portions of said preselected poeltionsf and energising means connected to said forward clip means and to said rea clip means supplying to said source of and a source of electrical energy a inverter stage means fo converting said electrical energy a first signal means for decreasing said first voltage to voltage less than said first voltage and switching for applying at least said signal said first voltage and other signal voltages to said source of electromagnetic arrangement in claim 3 further means for increasing the voltage of said electrical signal to a second voltage level greater than said firsts and said second voltage level provides a starting voltage to said source of said switching means further means for selectively applying said second voltage to said source of electromagnetic said rectifier stage comprises a said inverter a first transistor and a transistor and said first transistor and said second transistor having different transistor The arrangement defined in claim and further electrical chopper means and gap means for generating a high signal for starting said source of electromagnetic and means for selectively applying said high signal to said source of arrangement defined in claim 3 wherein said energizing means for supplying energy to said source of magnetic radiation further comprises electrical energy supply electrical chopper and gap means operatively connected said electrical energy supply menas for generatin a signal to start source o electromagnetic first capacitor connected to said source of electrical level aaid intermediate signal and aaid low level signal to aaid source of electromagnetic An portable searchlight to claim combinations a case a source electromagnetic radiation having a forward electrode and a rear electrode spaced from said forward electrode for emitting magnetic radiation in a preselected emitted magnetic radiation having in a reflector means coupled said case means for suppor therein in a predetermined and comprising a parabolic reflector means having a predetermined focal point on a preselected axis and adjacent said source of electromagnetic radiation for receiving a first portion of said electromagnetic radiation in said preselected distribution and reflecting first portion of said electromagnetic radiation therefrom in a preselected directional mounting means for supporting said source of electromagnetic radiation at preselected positions in spaced apart relationshi to said reflector said predetermined focal point comprising one of said and said mountin means an electrically conductive forward spring clip means coupled electrically conductive contact with said forward electrode of said source of radiation for retention of said source of electromagnetic radiation for the condition of of said source of electromagnetic radiation in portions of said preselected and electrically conductive rear clip means coupled in electrically conductive contact with said rear electrode of said source of electromagnetic shield means adjacent said source of electromagnetic radiation for a second portion of said electromagnetic radiation in said preselected distribution to prevent said second portion of electromagnetic radiation emission i a second preselected directional patter different from said first directional adjustment means on mounting moans for moving said of electromagnetic radiation into said preselected and said ment means axial for selectivel movin source of magnetic radiation along said axis relative to said means and said reflector means to first axial positions closer to and furthe from said reflector means and said focal point said first axial positions comprise said portion of preselected a radial adjustment means coupled to said forward spring clip and mounted on said case electrically insulating means coupled to clip and said axial movement means coupled to said electrically insulating shield support means for supporting shield means for movement with said source of electromagnetic radiation conditio of movement of said source of electromagnetic radiation second portions of said preselected and source of electromagnetic radiation moveable with respec said ehiled means for movement of source electromagnetic radiation in said first portions of said preselected The arrangement defined in Claim 7 electrically insulating comprises an electrically insulating member and aaid movement means comprises a knob mounted on said case means and engaging said threaded electrically means whereby rotation of said Isnob moves electrically means and said eource o electromagnetic radiation alon the axis of The defined in claim electrically insulating means comprises an electrically insulated bracket said axial movement means comprises a means having a end and a said electrically insulatin bracket means is pivotally coupled to said axial lever means intermediate aaid pivot end and and pivot end is pivotally on said case whereby movement of said adjustment end of said axial adjustment lever moves of radiation along said axis of said The arrangement defined in Claim 7 eaid axial adjustment means comprises three strut members extending from front spring clip means to said case a first and a second o said strut members adjustably coupled to eaid case means and the third strut member on said case An improved portable searchlight as herein and illustrated in Attorney for insufficientOCRQuality