具体实施方式：
[0107]The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the techniques or systems described herein in any way. Rather, the following description provides some practical illustrations for implementing examples of the techniques or systems described herein. Those skilled in the art will recognize that many of the noted examples have a variety of suitable alternatives.
[0108]To further an understanding of the present disclosure, specific exemplary embodiments according to the present disclosure will be described in detail. Frequent mention will be made in this description to the drawings. Reference numbers will be used to indicate certain parts in the drawings. Unless otherwise stated, the same reference numbers will be used to indicate the same parts throughout the drawings. Further, similar reference numbers (e.g., 702, 802, 902, 1002, 1102) will be used to indicate similar parts or functionality between embodiments. Reference numbers followed by letters (e.g., 100, 100a) may denote the same or similar features that may be symmetrical to each other, etc.
[0109]Regarding terminology, terms such as “means”, “devices”, “elements”, “parts”, “portions”, “structure”. “components”, and “members” may be used interchangeably herein, in the singular or plural, by way of convenience and not depart from aspects of the present disclosure, nor place limiting effects on aspects of the present disclosure unless explicitly stated otherwise.
[0110]Also, terms such as “having”, “including”, “with”, etc. or forms thereof are to be interpreted as being open, not limiting the parts of a structure that may be added to that structure. The term “generally linear”, “linear array” or forms thereof are to be interpreted to include arrays of items such as LEDs that follow a sweep path that is at least partially straight or is slightly curved so that a tangent at one end of the array forms an angle with a tangent at another end of the array that is less than 40 degrees.
[0111]Also, a number of terms have been used for reasons of convenience or explanation that should not be considered limiting beyond that which is presented herein. For example, the terms “luminaire(s)” and “fixture(s)” are used interchangeably herein, as they often are in the lighting industry. Neither term is intended to purport any specific limitations beyond those which are described herein.
[0112]As another example, reference is given herein to “ballast(s)” and “driver(s)”; while both are power regulating means for lighting technology, the former is used herein with respect to HID light sources and the latter is used with respect to LED light sources. However, it should be noted that where aspects of the disclosure applied to other kinds of light source (e.g., laser diodes), the corresponding terminology for the power regulating means may differ. It should be generally understood that various embodiments of the present disclosure are directed to lighting system retrofits and so any specific reference to a type of light source or power regulating means should be given its broadest interpretation.
[0113]For example, a ballast could encompass magnetic ballasts, electronic ballasts, and generally any AC power conditioning means, whereas a driver could encompass generic drivers (i.e., simple DC power conditioning means), so-called smart drivers (i.e., complex DC power conditioning means that may include programmable features, self-healing components, active feedback loops, etc.), or something in between. All of the aforementioned possibilities are contemplated to be within the scope of the present disclosure.
[0114]Lastly regarding terminology, reference may be given herein to terms such as “ray(s)”, “beam(s)”, “beam pattern(s)”, “beam shape(s)”, “composite beam(s)”, “beam design(s)”, or the like. All of these terms make reference to light projected from a lighting fixture. It is to be understood that the nature of light is complex and that the terms herein may generally describe the shape of light as projected onto a target area from a lighting fixture, or the intensity in an aerial space above a target area, or the general direction of light as it leaves a luminaire, or the like. While specific descriptions and illustrations are provided herein, it is to be understood that none of these terms, descriptions, or illustrations are to be considered all-encompassing of lighting concerns one may encounter during a retrofit situation; however, it should also be noted that all are commonly known terms and understood well in the art of lighting.
Overview
[0115]As previously stated herein, the present disclosure is directed to lighting system retrofits. More specifically, retrofits for specialized lighting systems are disclosed.
[0116]One such specialized lighting system is illustrated in FIGS. 1 thru 4. Here, a sports lighting system designed to illuminate a sports field 2 and some portion of the aerial space above the field is depicted. As can be seen from FIG. 1, site power is delivered via a transformer 4 or another device. Delivery of said power to HID fixtures 6 along power lines 8 is regulated and/or controlled at multiple points in the circuit (here, at a pole cabinet 10 (referred to later herein as an electrical component enclosure or ECE) on pole 12, at a control cabinet 14, and at a distribution cabinet 16).
[0117]If desired, additional control can be facilitated from an offsite control center 18 (e.g., via wireless communications to an antenna and control module located in control cabinet 14) such as is described in U.S. Pat. No. 7,209,958, or otherwise. Most sports lighting systems operate on three-phase power and require dedicated grounding 20, though as has been discussed, this varies widely from site to site. Power wiring is typically isolated from ground wiring (at least a portion of which may be integral to base 22) and, to the extent possible, internally routed to prevent theft and exposure to environmental effects.
[0118]In FIGS. 2 thru 4, the wiring 8 is internally routed through pole 12, into crossarm 24, through adjustable armature 26, and to each HID fixture 6 that may be arranged in an array 28. This is adequate description of a specialized lighting system which may be retrofitted according to and benefit from aspects according to the present disclosure, though additional background information is available in U.S. Pat. Nos. 6,250,596, 7,600,901, 8,163,993, 8,337,058, and 8,770,796, etc.
[0119]As has been discussed earlier herein, a retrofit situation occurs when the light source being replaced is somehow different from the light source replacing it. Typically, LED lights have different power requirements as compared to HID lights. In the context of retrofitting the sports lighting system of FIGS. 1 thru 4 from HID to LED, this translates to some sort of change to power regulating means at a pole cabinet 10. While power is distributed at the pole cabinet 10 and controlled (e.g., turned on and off in accordance with a preset schedule) at the control cabinet 14, power is ultimately conditioned and regulated for the particular load (i.e., one or more HID sources 6) at the pole cabinet 10 via ballast 30 and capacitor bank 32, and therefore is an aspect of the present disclosure as shown in FIGS. 5 and 6.
[0120]Another aspect of the present disclosure is at the top of the pole, namely, at a fixture level. Ideally, retrofit fixtures will fit in the existing crossarm footprint such that they may be pivoted left or right (sometimes referred to as panning) or pivoted up or down (sometimes referred to as tilting) without photometric or physical interference. Photometric interference occurs when light from one fixture (see light rays A and B in FIGS. 3 and 4) strikes another fixture in the system and causes onsite glare or other adverse lighting effects. This would occur, for example, if the topmost fixture 6 of FIG. 3 was pivoted downwardly such that light ray A struck the top of lowermost fixture 6a of FIG. 3 (i.e., the fixture associated with light ray B).
[0121]Physical interference occurs when certain aiming angles are precluded because fixtures would strike each other or some other portion of the lighting system. This would occur, for example, if the leftmost fixture 6b of FIG. 4 (i.e., the fixture associated with light ray A) was pivoted sideways into the next fixture 6c (i.e., the fixture associated with light ray B). Both photometric and physical interference reduces useful light-namely, light that is useful for the particular application (here, the illumination of sports field 2 and the aerial space above field 2).
[0122]It may be tempting to assume that photometric and physical interference in a retrofit system is simply a matter of poor aiming or lighting design, but it is important to note that if the retrofit fixture itself is not matched well to the application in terms of needed light levels, needed glare control, and existing pole location/weight loading limits, then extreme aiming is sometimes the only recourse to produce the needed lighting design. Other times, despite exceptional luminaire design, wiring is too degraded or crossarms are warped, or existing light levels grandfathered in are too low for a retrofit situation, and so the best recourse is retrofitting a full array of LED luminaires on a new crossarm with a new wiring harness-which has the added benefit of being tested for photometric and physical interference at the factory. All of this is addressed in some of the embodiments set forth herein.
[0123]Further, existing specialized lighting systems such as that just described which are retrofitted to include LED luminaires on a one-for-one basis—as is currently being done in the industry-often result in a significant loss of glare control (onsite and/or offsite). To combat the increase in glare, state-of-the-art LED retrofit fixtures are often capped, blackened, coupled with light blocking devices, etc. which can be effective means of reducing glare—but also reduces overall light output, which necessitates more fixtures to get light levels comparable to the former HID lighting system. This can create an issue with respect to the weight the existing poles or crossarms can withstand, and the available space on the crossarm (as discussed for FIGS. 3 and 4). It may be tempting to believe that LEDs are always a better choice than an older lighting technology-they do indeed have exceptionally long life when operated properly—but this can come at the cost of glare control (which is often not even understood to be an issue until a sub-par retrofit system is installed). This too is addressed in some of the embodiments set forth herein.
[0124]The exemplary embodiments envision apparatuses and methods for designing specialized LED retrofit lighting systems in a manner which resolves disparate power requirements, addresses needed lighting conditions, preserves most of the existing lighting system, and is more cost effective and customizable than that which is currently available in the art. These exemplary embodiments, utilizing aspects of the generalized examples already described, will now be described herein.
Retrofit Electronic Component Enclosure
[0125]Turning now to FIGS. 7 thru 26 and 47, various embodiments associated with adjusting the power supplied by a previously installed lighting system utilizing HID lamps using some of the existing components of that system will now be discussed.
[0126]Starting with FIGS. 7 and 8, a modified ECE is shown where some of the ballasts previously used to power HID lamps have been removed and replaced by a self-contained ballast driver assembly that is in communication with at least one of the remaining ballasts. In some applications, one such driver assembly and associated ballast will power two LED fixtures, but not necessarily so. In certain embodiments, three ballasts may be removed, and three ballast drivers may be installed into the ECE in their place. Three existing ballasts and the existing capacitors may still be used. In yet further embodiments, the number of ballasts, capacitors, and ballast drivers may be reduced since LED lighting is inherently more efficient than HID lighting. Conversely, a dedicated or new ECE may be supplied with more ballasts and ballast drivers to increase the amount of lighting in terms of luminosity levels or area covered at a site with a previously installed HID lighting system, etc.
[0127]Such an ECE 100 includes one or more ballasts 30 as previously alluded to herein and one or more self-contained ballast drive assemblies 200 that are in electrical communication with the ballast(s) 30 for supplying (DC) direct current to an LED. More specifically, the self-contained ballast drive assembly 200 may comprise a circuit board 302, as well as a circuit board enclosure 204 (may be fabricated from sheet metal) surrounding the circuit board 302 for its protection and reliable mounting in the ECE 100.
[0128]Focusing on FIG. 7 by itself, the ECE may be described as follows as a separate and sellable item. The ECE 100 may comprise a sidewall 102, a bottom wall 104, a first ballast 106 attached to the sidewall 102 as shown or the bottom wall, and a first ballast driver (e.g., a self-contained ballast drive assembly) attached to the sidewall 102 as shown, or the bottom wall adjacent to the first ballast 106.
[0129]Similarly, a second ballast 106a may be attached to the sidewall 102 as well as a third ballast 106b, while a second ballast driver 200a as well as a third ballast driver 200b may be attached to the sidewall 102 as shown or the bottom wall. The first, second, and third ballasts may be arranged in a linear array, while the first, second, and third ballast drivers may form a linear array next to that of the ballasts.
[0130]In a retrofit application, the first ballast driver, the second ballast driver, and/or the third ballast driver may occupy space vacated by removed a plurality of previously installed ballasts. This may not be the case when the ECE is supplied as a new assembly.
[0131]More specifically, the ECE may take the form of a polygonal sheet metal enclosure (e.g., may be rectangular) such that the sidewall 102 includes a plurality of panels 108, 108a forming a polygonal perimeter 110, and the bottom wall 104 is adjacent to or even attached to the plurality of panels 108 such as when the ECE is folded into shape.
[0132]As shown in FIG. 7, the plurality of panels may include a first panel 108, and a second panel 108a that is parallel to the first panel 108, and the first ballast 106, the second ballast 106a, and the third ballast 106b may be attached to the first panel 108, while the first ballast driver (e.g., see 200), the second ballast driver 200a, and the third ballast driver 200b may be attached to the second panel 108a. Also, the first ballast driver, the second ballast driver, and the third ballast driver may be identically configured (i.e., within manufacturing tolerances of +/−0.020 of an inch). Other configurations and arrangements of the ECE and these components are possible in other embodiments of the present disclosure.
[0133]As alluded to earlier herein, the first ballast may in electrical communication with the first ballast driver, the second ballast may be in electrical communication with the second ballast driver, and the third ballast may in electrical communication with the third ballast driver e.g., via wires (not shown).
[0134]The first and second panels 108, 108a may be parallel to each other but not necessarily so. The ballasts may be attached to the first panel, while the ballast drivers may be attached to the second panel. This may not be the case in other embodiments of the present disclosure. For example, the ballasts and ballast drivers may alternate along one of the panels, etc.
[0135]Still referring to FIG. 7, a DIN (Deutsche Institut fir Normung) rail 112 may extend from panel 108, 108a below the third ballast 106b and the third ballast driver 200b. A plurality of fuses 114 or circuit breakers may be attached to the DIN rail 112. Those fuses or circuit breakers no longer being used when ballasts are removed may also be removed, but not necessarily so.
[0136]As will be discussed in further detail later herein, a cam motor assembly 34 associated with Smart Lamp® technology, or a manual cam assembly may be disposed beneath the DIN rail 112 adjacent to panel 108, and a bank of capacitors 116 may be disposed beneath the DIN rail 112 adjacent to the panel 108a, and adjacent to the cam motor assembly 34 or the manual cam assembly. The cam motor assembly 34 or the manual cam assembly may include a lever configured to rotate one or more cams so that different selected capacitors of the bank of capacitors is connected to the power line going to the ballast(s), etc. A wire entrance and a wire exit (may be supplied by a single aperture 118) may be formed in the bottom wall 104. The number and placement of the capacitors, the cam assembly, the wire entrance, and the wire exit may differ in other embodiments of the present disclosure.
[0137]The self-contained ballast driver assembly(s) 200 may be attached via fastener and bracket combination 120 and a toe 124 that mates with a flange 122 that is used in previous ECEs for attaching ballasts to the sidewall. Other methods of attachment are possible in other embodiments of the present disclosure.
[0138]Looking now at FIG. 15, an alternate ECE 100a that is similarly or identically configured as ECE 100 is shown except that uses self-contained ballast driver assembly(s) 200c that have dual PCBs to power more luminaires as will be described in further detail later herein. Also, the driver assemblies 200c are disposed lower in the ECE on either side (e.g., immediately approximate the DIN rail 112 on a first sidewall or the bottom wall, and on a second sidewall or the bottom wall a across from each other) to promote efficient cooling of the PCBs. For example, the heat from one driver does not rise through natural convection to the next driver. In addition to or in lieu of this effect, the driver assemblies may be further away from the traditional ballasts that create heat that rises away from the now lower disposed driver assemblies. The fact that the driver assemblies 200c have two PCBs instead of only one allows the elimination of the two higher placed driver assemblies 200, 200a in FIG. 7.
Circuit Board Enclosure
[0139]Referring now to FIGS. 8 thru 12, the circuit board enclosure 204 may include a five-sided cover 206, and a three-part mounting bracket 208. The five-sided cover 206 may include a front panel 210 defining a plurality of connector receiving windows 212, a top panel 214 defining a plurality of vent openings 216, and a bottom panel 218 defining a plurality of vent apertures 220. The five-sided cover 206 may also have a first side panel 222, and a second side panel 224. The first side panel 222 may define a plurality of first side apertures 226, while the second side panel 224 may define a plurality of second side apertures 228. These apertures may allow a wire end keeper to be attached to this enclosure as will be described in more detail later herein.
[0140]As best seen in FIGS. 8 and 11, the top panel 214 may include a first pair of attachment flanges 230, 230a extending down from the top panel 214 defining a first pair of attachment apertures 232, 232a, and the bottom panel 218 may include a second pair of attachment flanges 230b, 230c extending upwardly from the bottom panel 218 defining a second pair of attachment apertures 232b, 232c.
[0141]Also, the top panel 214 may be connected to the front panel 210 by a plurality of top bends 234, 234a, 234b that are each separated by a top cutout 236, 236a. Likewise, the bottom panel 218 may be connected to the front panel 210 by a plurality of bottom bends 234c, 234d, 234e that are each separated by a bottom cutout 236b, 236c. These cutouts may facilitate bending of the panels without tearing or the use of too much force. These cutouts may be omitted in other embodiments of the present disclosure.
[0142]Referring to FIGS. 9, 10 and 12, the three-part mounting bracket 208 may include a first side circuit board mounting portion 238, a second side circuit board mounting portion 238a, and a top enclosure attachment portion (may also be referred to as a handle portion 240) connecting the first side circuit board mounting portion 238 to the second side circuit board mounting portion 238a. The top enclosure attachment portion or handle portion 240 may include an elongated aperture 246 (racetrack or oval shaped, etc., may be used to mount to the ECE using fastener and bracket combination 120 alluded to earlier herein). The handle and this aperture may be obscured by a cover (not shown) until it is ready to be mounted. This cover may also protect the back surface of the heat sink and/or the thermally conductive and electrically insulating material before this mounting step is complete.
[0143]The handle portion 240 may be joined to the first side circuit board mounting portion 238 by a first side bend 248, and the top enclosure attachment portion or handle portion 240 may also be joined to the second side circuit board mounting portion 238a by a second side bend 248a. The first side bend 248 may be split by a first side cutout 250, while the second side bend 248a may be split by a second side cutout 250a.
[0144]More particularly, the first side circuit board mounting portion 238 may include a first pair of cover mounting holes 242, 242a and a first pair of attachment flange receiving notches 244, 244a disposed proximate to the first pair of cover mounting holes 242, 242a. Similarly, the second side circuit board mounting portion 238a may include a second pair of cover mounting holes 242b, 242c, and a second pair of attachment flange receiving notches 244b, 244c disposed proximate to the second pair of cover mounting holes 242b, 242c.
[0145]Moreover, the first side circuit board mounting portion 238 may define a first circuit board receiving slit 252, and the second side circuit board mounting portion 238a may define a second circuit board receiving slit 252a. The first side circuit board mounting portion 238 may also define a first side heat sink receiving aperture 254, and the second side circuit board mounting portion 238a may further define a second side heat sink receiving aperture 254a.
[0146]Focusing on FIG. 12, the first side heat sink receiving aperture 254 may be spaced away from the first circuit board receiving slit 252, and the second side heat sink receiving aperture 254a may also be spaced away from the second circuit board receiving slit 252a. The first side circuit board mounting portion 238 may also define a third circuit board receiving slit 252b that is in communication with the first side heat sink receiving aperture 254, and the second side circuit mounting portion 238a may also define a fourth circuit board receiving slit 252c that is in communication with the second side heat sink receiving aperture 254a. The first side heat sink receiving aperture 254 may be L-shaped, and the second side heat sink receiving aperture 254a may be L-shaped. These apertures are generally complementarily shaped to receive the heat sink of the circuit board. Other configurations are possible in other embodiments of the present disclosure.
[0147]As shown in FIGS. 8 thru 10, the enclosure 204 may be adapted to hold and contain a circuit board and heat sink assembly 300 that may comprise a circuit board 302 as alluded to earlier herein. The method of forming the enclosure about the circuit board and heat sink assembly will be discussed in further detail later herein.
[0148]Looking now at FIGS. 16 through 19, it can be seen that driver assembly 200a is similarly or identically configured as that shown in FIGS. 8 thru 10 except for at least the following differences. The enclosure 204a is taller than the enclosure 204 in FIGS. 8 thru 10 (may be 50% to 100% taller). More particularly, the lower edge 209 (see FIG. 17) of the mounting bracket 208a proximate its toe 124a is lower than that of enclosure 204, and the rest of the mounting bracket 208a and the cover 206a are mirrored about plane 211 in FIG. 19 so that two PCBs (see 300a) can be accommodated. Due to the increased height, an extra bend 234c and cutout 236b (see FIG. 16) may be provided to allow the cover to be folded during manufacturing. Also, the bottom edge 213 of the handle portion 240a of the mounting bracket 208a has been moved up to accommodate the taller cover 206a. Additional connector receiving windows 212a are also provided to allow wire connection to the top PCB.
[0149]Other changes for the cover include an additional top flange 256 that extends from the handle portion 240a to provide more stability when the driver assembly 200a is seated in the ECE 100a. Furthermore, the vent openings 216a have been moved from the top of the cover to the side panels of the mounting bracket and enlarged (may be pie or wedge shaped, see FIG. 17) to provide extra ventilation since the heat generation may be doubled due to the use of two PCBs.
[0150]The side apertures 226a are differently configured (round instead of polygonal) since there may be no need for a wire keeper. These apertures may also provide for additional cooling, etc. Also, a cross-brace 258 is provided connecting the toes 214a to provide rigidity to the enclosure after it has been assembled. The cross-brace may also help to prevent the PCB(s) from being compressed or damaged.
Circuit Board and Heat Sink Assembly
[0151]As depicted in FIGS. 13 and 14, the circuit board and heat sink assembly 300 may include such a circuit board 302 that has a top circuit mounting surface 304, and a plurality of side mounting tabs 306 that are configured to fit within the slits of the enclosure as alluded to earlier herein. Also, a plurality of circuitry components 308 may be attached to the top circuit mounting surface 304, as well as a heat sink 314 that is attached to the top circuit mounting surface 304 that is in thermal communication but electrical isolation with one or more of the plurality of circuitry components 308. To that end, a thermally conducting and electrically insulating material 312 may be disposed between one or more of the plurality of circuitrv components 308, and the heat sink 314. Specifically, the thermally conducting and electrically insulating material may comprise silicone and alumina, etc. For example, the alumina may be AL204 with a 96% purity. Other types of thermally conducting and electrically insulating material may be used in other embodiments of the present disclosure.
[0152]As alluded to earlier herein, the heat sink 314 may be L-shaped as alluded to previously herein, and may be made from aluminum (e.g., an aluminum alloy). For example, extruded 6063-T5 aluminum may be used. Other configurations and material may be employed as long as a suitable amount of heat is removed from the electrical components, etc.
[0153]Looking at FIGS. 8 and 13, a plurality of connectors 316 may be disposed near the front of the top circuit mounting surface that are in communication with the plurality of circuitry components. This allows wires from the ballasts, etc. that are already in the ECE to be connected to the circuit board and the heat sink assembly quickly, and also allows wires leading from this assembly to the LED fixtures to also be connected easily, or vice versa.
[0154]Turning now to FIGS. 17 thru 21, a circuit board and heat sink assembly 300a that is similarly or identically configured as that of FIGS. 8 thru 13 except for at least the following differences will now be discussed.
[0155]Focusing on FIGS. 20 and 21, the heat sink 314 may define a clip receiving groove 318 at least partially defined by a top ledge 320, and a bottom catch rib 322. One or more clips 324 that may be disposed in the clip receiving groove 318 and contacting at least one of the plurality of circuitry components to press it into contact with the electrically insulating and thermally conductive material.
[0156]The plurality of side mounting tabs includes a front mounting tab 306a, a rear mounting tab 306b, and an intermediate mounting tab 306c that is disposed between them. The front mounting tab has been added to provide an abutment surface against the cover so that the assembly 300a is not prone to twist. A pan 326 for receiving the heat sink 314 may be disposed between the heat sink 314, and the circuit board 302. The pan is fabricated from an electrically insulating material, a thermally insulating material, or both. For example, the pan may take the form of an injection molded plastic part that is electrically insulating. The specific material may be Polybutylene Terephthalate (PBT), etc.
Circuit
[0157]FIGS. 22 and 23 contain a circuit(s) for rectifying and supplying power to a LED luminaire. In FIG. 22, such a circuit 400 may comprise a ballast(s) 106 and a capacitor bank 116 as alluded to earlier with reference to FIG. 7.
[0158]However as shown in FIG. 23, such a circuit 400 may further include a rectifying subcircuit 402, an open circuit protection subcircuit 404, an output conditioning subcircuit 406, and a power surge protection subcircuit 408. In particular embodiments, the power surge protection subcircuit 408 may comprise a gas discharge tube GDT1 (fuses may also be provided such as F1 and F2, other external surge protection devices, etc., but not necessarily so). Also, metal oxide varistors (MOVs) designated as Z1, Z2, and Z3 are provided. Z1 and Z2 provide surge suppression when voltage in common mode reaches a maximum value whereas Z3 provides surge suppression when voltage in differential mode reaches another maximum value. The gas discharge tube has a different failure mode as compared to the MOVs to provide another level of protection or safety. Specifically, MOVs typically fail by going short circuit whereas gas diode tubes typically fail going open circuit. With the arrangement shown, it most likely current will be sent to ground, regardless if any of the MOVs or the gas discharge tube fail.
[0159]The rectifying subcircuit 402 includes a diode bridge D1 that is a commercially available full wave bridge rectifier diode bridge. Other rectifying subcircuits may be employed.
[0160]The open circuit protection subcircuit 404 may include Zener Diodes designated as D3, D4, and D5 that are electrically connected in parallel to a thermistor designated as R5 and a switching thyristor designated as D2. When the voltage is too high, the current from the rectifying subcircuit is sent to ground. The voltage values for the D3, D4, and D5 may range from 100 volts to 600 volts in some embodiments of the present disclosure.
[0161]Turning now to the output conditioning subcircuit 406, it includes a conditioning bank of capacitors C1, C2 that are designed to reduce the electrical ripple (or the resulting optical flicker) of the AC component of the direct current supplied by the rectifier D1. The values of these capacitors C1, C2 may range from 100 μF to 4000 μF in some embodiments of the present disclosure. In some embodiments, zero or nearly zero capacitance may be required, while in other embodiments an even greater value than 4000 μF may be needed to reduce the optical flicker to a desired level, etc. Resistors R6 and R7 are supplied to discharge the capacitors C1, C2 when the power is turned off to allow for safe interaction during maintenance, trouble shooting, etc. Another fuse F3 may be provided to prevent damage to the luminaire if current is too high, but not necessarily so. Also, a MOFSET (not shown) may be interposed between the open circuit protection subcircuit, and the output conditioning subcircuit to provide another level of protection.
[0162]Any of the components may be “thru-hole” components or “surface mount” (e.g., see FIGS. 13 and 14) components depending on the application, availability of components, design needs, cost, etc.
[0163]In some embodiments, an HID ballast-capacitor circuit producing a constant wattage on the order of 1500 W at a capacitance of 32 μF might be replaced with a capacitor bank having a capacitance on the order of 28 μF so as to produce a constant wattage on the order of 900 W, which may be an adequate wattage to operate the 224 XM-L LEDs (available from Cree LED, Inc., Durham, N.C.) that is wired in parallel with two strings of 112