The subject matter described herein relates to a luminaire and, more specifically, to a low profile luminaire and to a luminaire design. In addition, the subject matter described herein relates to a light engine and a lighting circuit and, more specifically, to a magnetics-free light engine with high performance and a low profile design and to a modular integrated lighting circuit.
In operation, luminaires may generate heat; and due to a proximity of the luminaires to a wall or a ceiling on which the luminaires can be mounted, low profile luminaires may experience a greater rise in temperature than, for example, larger profile luminaires which can have a larger surface area and thus may be able to better dissipate heat. Therefore, in some instances, it can be difficult to use low profile luminaires in environments having, for example, a high ambient temperature. In addition, traditional brackets used for mounting luminaires may make it difficult to mount a luminaire to a wall or ceiling while also maintaining a low profile of the luminaire. These problems can increase an overall shape, dimension, or profile of the luminaire and can also increase costs and manufacturing time of the luminaire.
In addition, when light emitting diodes (LEDs) are used as a light source of the luminaire, the LEDs (or group of LEDs) require a special driver for converting an input electrical power to an electrical power that is suitable for powering the LEDs (or group of LEDs). Therefore, configuring multiple LEDs (or groups of LEDs) requires special attention to the driver needed to power each of the multiple LEDs (or groups of LEDs). As a result, configurations with multiple LED boards can be difficult to modify or scale without undertaking significant redesign, thereby increasing costs and manufacturing time. Such limitations can also make it difficult to interchange LEDs or to dynamically configure an LED luminaire for a desired application. A low profile LED light engine (e.g. an LED driver and LED circuit boards) having high performance characteristics (e.g. high temperature capability, power factor (PF), total harmonic distortion (THD), flicker, reliability, etc.) can also be desirable.
According to a first example of the disclosure, a luminaire comprises a body comprising a lighting compartment; and at least one LED circuit board, wherein the LED circuit board is secured along a base of the lighting compartment by at least one clamp extending longitudinally along and secured to a side of the lighting compartment.
In various embodiments of the above example, the clamp has a reflective surface for reflecting light emitted by an LED on the at least one LED circuit board; the clamping plates apply a clamping force along a longitudinal edge of the at least one LED circuit board in a direction toward the base of the lighting compartment; the clamping force increases contact between the at least one LED circuit board and the base of the lighting compartment, the base acting as a heatsink for the at least one LED circuit board; a profile of the luminaire comprises an outermost dimension of less than about two inches; the at least one clamp provides a ground path for electrical circuits of the luminaire; the at least one clamp extends a full longitudinal length of the lighting compartment; each of the at least one clamps has a longitudinal dimension substantially similar to a longitudinal dimension of a corresponding one of the at least one LED circuit boards; each of the at least one clamps secures the corresponding one of the at least one LED circuit boards; the at least one clamp is made from a flexible material and deforms from a planar surface as the at least one clamp is secured to the side of the lighting compartment; and/or the luminaire comprises at least two clamps extending longitudinally along and secured to opposite sides of the lighting compartment.
According to a second example of the disclosure, a luminaire comprises at least one LED circuit board secured in a lighting compartment, wherein the LED circuit board is secured along a base of the lighting compartment by at least one clamp extending longitudinally along and secured to a side of the lighting compartment, and a profile of the luminaire comprises an outermost dimension of less than about two inches.
In various embodiments of the above example, the clamp has a reflective surface for reflecting light emitted by an LED on the at least one LED circuit board; the clamping plates apply a clamping force along a longitudinal edge of the at least one LED circuit board in a direction toward the base of the lighting compartment; the clamping force increases contact between the at least one LED circuit board and the base of the lighting compartment, the base acting as a heatsink for the at least one LED circuit board; the at least one clamp provides a ground path for electrical circuits of the luminaire; the at least one clamp extends a full longitudinal length of the lighting compartment; each of the at least one clamps has a longitudinal dimension substantially similar to a longitudinal dimension of a corresponding one of the at least one LED circuit boards; each of the at least one clamps secures the corresponding one of the at least one LED circuit boards; the at least one clamp is made from a flexible material and deforms from a planar surface as the at least one clamp is secured to the side of the lighting compartment; and/or the luminaire comprises at least two clamps extending longitudinally along and secured to opposite sides of the lighting compartment.
The first and second examples, and their various embodiments, may also be combined in any combination.
Certain terminology is used herein for convenience and is not to be taken as a limitation on the present application. Relative language used herein is best understood with reference to the drawings, in which like numerals are used to identify like or similar items. Further, in the drawings, certain features may be shown in a somewhat schematic form.
The following aspects described herein are related to a luminaire. While the luminaire is described with respect to a light source including light emitting diodes (LEDs) for illumination, it is to be understood that the aspects described herein could also apply to luminaires with other light sources as forms of illumination or lighting. Additionally, the luminaire may be used for any type of lighting, for example, accent, indicator, general lighting, high bay, modular, flood, linear lighting, and any other type of lighting including those types not explicitly described herein.
Unless otherwise stated, the term “lumens” is to be understood to refer to the standard unit of a measure of the total amount of visible light emitted by a source. In addition, unless otherwise stated, the term “power factor” is to be understood to refer to the standard dimensionless unit of a measure, in the closed interval between −1 and 1, relating to an AC electrical power system defined as the ratio of the real power flowing to the load to the apparent power in the circuit.
According to a first aspect, the luminaires are formed to have a low profile which provides greater flexibility in terms of locations and positions of installation of the luminaires. The subject luminaires also do not exhibit traditional deficiencies such as overheating from their low-profile form. Consequently, the low profile luminaries of the subject application can be employed in environments having a wide range of temperatures, and particularly, in environments having a high ambient temperature. Many structural features of the subject luminaires are described below and contribute to the low profile form as well as to the high temperature tolerance of the luminaires. For example, the luminaires can have a height dimension smaller than a width and a length dimension. In addition, specific mounting elements can employed that minimize bulk and preserve the low profile features of the luminaires even once they have been installed. As a result, the luminaires remain close to a ceiling, wall, or any surface on which they are mounted. Further, the overall structure of the luminaires, including interior components promotes the dissipation of heat generated by the luminaires; thus allowing the luminaires to be fully operable in high ambient temperature environments. The low profile luminaires disclosed herein can also cost less to manufacture than the conventional luminaires.
A perspective view of a first example luminaire 100 is illustrated in
In other embodiments, as shown with respect to a second example luminaire 200 (
Turning back to
It is to be understood that the wiring connection terminals 110 may be formed as any electrical connector including, for example, crimping connectors, screw connectors, blade connectors, and any other electrical connector including those not explicitly described herein. Moreover, it is to be understood that, in some examples, the wiring connection terminals 110 may be optional and may therefore be provided as a convenience to users or to meet certification requirements. Thus, in other examples, a main power (e.g. 120 V AC power) could be wired directly to terminals mounted on the one or more LED circuit boards 108, thus eliminating the need to include the wiring compartment 106 and the wiring connection terminals 110 arranged therein.
Further, the first example luminaire 100 can be electrically connected to one or more additional luminaires (e.g. one or more luminaires that are the same as or similar to the first example luminaire 100 and/or one or more luminaires that are different than the first example luminaire 100, such as any one or more of the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400, as well as any other luminaire including those luminaires not explicitly disclosed herein) by passing a wire or cable from the first example luminaire 100 to the one or more additional luminaires. For example, as shown in
A wiring configuration of the first example luminaire 100 will now be described with the understanding that such wiring configuration can apply in a same or similar manner to any one or more of the example luminaires disclosed herein, including the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400. As shown in
In addition, a plurality of LED circuit boards 108 can be physically and electrically connected to each other according to any desired configuration using a negative or neutral connector 127 and a positive connector 129 (shown in
Turning to
In addition, the LED light engine 500 includes a driving circuit region 503 and a light emitting region 504. The drive circuit 505 (e.g. magnetics-free drive circuit discussed below) is mounted to the LED circuit board 108 in the driving circuit region 503; and the LEDs 509 (e.g. individual light emitting diodes) are mounted to the LED circuit board 108 in the light emitting region 504. Power in and out connections 510, 512, 514, 516 (each having positive/hot and negative/neutral connectors) are also mounted at both ends of the LED circuit board 108—for example, at the driving circuit region 503 and at the light emitting region 504, respectively. The power in and out connections 510, 512, 514, 516 can be, for example, pin connectors electrically and physically connected to corresponding wires and connectors. For example, with respect to the first example luminaire 100 discussed above, the negative or neutral connection wire 126 and the positive connection wire 128 can connect to the respective power in and power out connections 510, 512 at the driving circuit region 503 of the LED light engine 500. Similarly, the negative or neutral connector 127 and the positive connector 129 can connect to the respective power in and power out connections 514, 516 at the light emitting region 504 of the LED light engine 500. The connection wires 126, 128 and connectors 127, 129 can physically and electrically connect a plurality of LED circuit boards 108 according to any desired configuration. It is also possible for the power in and out connections 510, 512, 514, 516 to be positioned at locations other than at the ends of the LED circuit board 108 to support various desired physical configurations of a plurality of LED circuit boards 108 connected either in series or in parallel.
In other embodiments, the LED circuit board 108 and drive circuit 505 can be on separate electrically connected circuit boards. For example, as shown in
The modularity of the luminaire as described above facilitates modification to the overall design of the luminaire which contrasts sharply with conventional modular luminaires. In traditional modular luminaires, a drive circuit is inherently limited by some feature or property, e.g., voltage, wattage, current, and the like. As a result, the modularity of the luminaire is necessarily also limited. For example, a drive circuit may be capable of powering a 50 W luminaire. The 50 W luminaire may comprise two 25 W LED circuit boards, five 10 W LED circuit boards, or other such combinations to equal 50 W. However, if 50 W becomes insufficient and a higher wattage is desired from that luminaire, then the drive circuit would have to be re-designed to support the additional wattage. By contrast, the subject luminaire as described above provides the ability to change the number of LED circuit boards employed without altering the drive circuit. This is because each LED light engine 500 has a driving circuit region 503 and is designed for the LED light strings of the light emitting region 504, thereby eliminating the need for a global driving circuit that powers every light emitting region 504. Accordingly, a quantity of the LED light strings that may be used is independent (e.g., not limited by) the use of a particular driving circuit.
Still referring to
The status of the semiconductor switches 603, 605, 609 can be dependent on a voltage of the AC input 602 at a specific time indicating which of the respective one or more of the plurality of LED light strings 604, 606, 610 will receive power from the AC input 602 at the specific time. For example, the number of LED light strings that are powered may be related to the AC input voltage. That is, according to one example, if the input is below 20 V, no LED light strings are powered; if the input is between 20 and 39 V, one LED light string is powered; if the input is between 40 and 59 V, two LED light strings are powered; if the input is between 60 and 79 V, three LED light strings are powered; and if the input is above 80 V, four LED light strings are powered. Thus, at any time, there can be no or any one or more of the plurality of LED light strings 604, 606, 610 connected to the drive circuit 505 via the corresponding semiconductor switches 603, 605, 609. Additionally, capacitors can store electrical energy to allow the LED light strings to remain illuminated during periods when the semiconductor switches are disconnecting the LED strings from the input power sources.
The semiconductor switches 603, 605, 609 may selectively provide power to the LED light strings 604, 606, 610 according to any circuit arrangement. For example, according to one embodiment, each semiconductor switch may be provided across (parallel to) a corresponding LED light string. In another embodiment, each semiconductor switch may connect a front (+) end of an LED light string to ground or an input of the current regulator. In yet another embodiment, each semiconductor switch may connect a back (−) end of an LED circuit string to the output of the drive circuit 505. In still another embodiment, a first semiconductor switch may be provided across (parallel to) a plurality of LED light strings, where additional semiconductor switches are provided across (parallel to) each of (or a subset of) the plurality of LED light strings. Still additional semiconductor switches may be provided across (parallel to) other LED light strings not enclosed by the first semiconductor switch. It is noted that still other arrangements may be used without departing from the scope of the present disclosure.
The magnetics-free drive circuit 505 can include high-efficiency components that reduce power loss and match an LED voltage in order to achieve greater efficiency. The LEDs 509 can also be arranged in a spaced relationship with respect to each other so as to evenly distribute heat that is generated by the LEDs 509 when powered or illuminated. Accordingly, a single LED light engine (e.g. the LED light engine 500) having, for example, a 40 W input power and high temperature components can operate with a circuit board temperature (e.g. a temperature of LED circuit board 108) greater than about 85° C. with a predicted lifetime of more than about 60,000 hours. The LED light engine 500 including the LED circuit board 108 and the modular integrated circuit 600 including the magnetics-free drive circuit 505 and the plurality of LED light strings 604, 606, 610 can also maintain a low-profile shape with respect to the luminaire (e.g. the first example luminaire 100, the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400) in which the LED light engine 500 and/or the modular integrated circuit 600 are configured to be installed.
For example, the LED light engine 500 comprises the magnetics-free drive circuit 505 and an LED illumination circuit that provides power to the LED light strings 604, 606, 610. In various embodiments, the drive circuit 505 and the illumination circuit may be separated by regions on a single circuit board 108 as discussed above. However, in other embodiments, each circuit may be on separate circuit boards that are electrically connected. It is also noted that the geometry of the circuits and circuit boards is not limited to squares and rectangles. Rather, for example, the circuit boards and circuits thereon may take a round or circular shape. In still other embodiments, the circuits may be formed concentrically on either a single or separate circuit boards.
Furthermore, the configuration of the subject luminaire yields higher performance which may be the result of a higher power factor, lower total harmonic distortion, lower flicker, higher operation temperature, and/or higher reliability of components. Total harmonic distortion refers to a standard unit of a measure of the harmonic distortion of a signal present, defined as the ratio of the sum of all harmonic components to the fundamental frequency component. Flicker is generally characterized by flicker percentage and flicker index. The term “flicker percentage” refers to a measure of the depth of modulation of flicker. Similarly, the term “flicker index” refers to a measure of the light intensity cycle based on the comparative duration of high and low levels of light relative to the average intensity (e.g. accounting for different shapes or duty cycles that a periodic waveform can exhibit).
The LED light engine 500 and the modular integrated circuit 600 can be configured to have at least one of an output of at least 2000 lumens (e.g. lm+), a power factor greater than about 0.9, a total harmonic distortion of less than about 20%, a flicker percentage of less than about 40%, and a flicker index of less than about 0.15. The LED light engine 500 may achieve such results with a lifetime greater than about 60,000 hours at 85° C. across an entire input voltage range. For example, the power factor is greater than about 0.999, the total harmonic distortion less than about 1.5%, flicker percentage less than about 35%, and the LED light engine has a lifetime greater than about 60,000 hours at 85° C. across with an input voltage of 120 V AC±10% (108-132 V AC) or 230 V AC±10% (207-253 V AC). Such performance may be achieved according to the above and below described configuration of the drive circuit 505, while still maintaining the low profile (e.g., less than 1 inch) described herein. Typically, a luminaire profile was constrained by part size (e.g., required capacitors that have dimensions that restrict or prohibit a low-profile design) and desired lumen output. In particular, total harmonic distortion is reduced by matching LED light string voltage and input voltage with more LEDs (and/or LED light strings) powered at higher voltages. Furthermore, flicker is controlled by placing a parallel capacitor to each LED string.
In some examples, the LED light engine 500 and the modular integrated circuit 600 can have an outermost dimension (e.g. a height measured from a first outermost point on a first side to a second outermost point on a second side that is opposite the first side) of less than about one inch. In other examples, the LED light engine 500 and the modular integrated circuit can have an outermost dimension of less than about one inch such that an overall profile with respect to a height of the LED light engine and the modular integrated circuit board 600 fits within (e.g. entirely within) an area or space defined by the outermost dimension. This outermost dimension (e.g. height) of the LED light engine 500 and the modular integrated circuit 600 can be achieved when the magnetics-free drive circuit 505 and LEDs 509 are arranged on the same LED circuit board 108 (e.g. as illustrated in
For example, an outermost dimension can refer to a largest dimension of a component in a particular direction, such that all dimensions of the component with respect to that particular direction are less than or equal to the largest dimension. Thus, in some examples, the outermost dimension may define an overall profile dimension with respect to a particular direction within which one or more components or elements can fit. For example, an LED light engine 500, LED circuit board 108, drive circuit 505, or modular integrated circuit 600 with an outermost dimension of less than about one inch can refer to an LED light engine 500, LED circuit board 108, drive circuit 505, or modular integrated circuit 600 having an overall profile configured to fit within an area defined with respect to at least one particular dimensional direction by the outermost dimension of less than about one inch. In other examples, all components associated with the LED light engine 500, the LED circuit board 108, the drive circuit 505, or the modular integrated circuit 600 can have outermost dimensions such that all of the outermost dimensions are less than about one inch.
In another example, described with respect to the third example luminaire 300 shown in
A cross-sectional view of the clamping plate 375 is illustrated in
It is also noted that a base of the lighting compartment 304 may serve as a heatsink for removing heated air from the luminaire 300 (as described in more detail below). Thus, by securing LED circuit board 108 to the lighting compartment 304, the clamping plate 375 also provides enough force to create a contact area between the LED circuit board 108 and the lighting compartment 304. Heat can therefore be transferred between the LED circuit board 108 and the lighting compartment 304. As described below, the lighting compartment 304 is exposed to a gap in a split fin structure 425 of the luminaire 300 that allows the flow of heat outwardly from the center of the luminaire 300. In sum, heat generated by LED circuit board 108 may thus be efficiently removed from the luminaire 300. The pressure required to create such contact can be achieved using the above described clamping plate 375.
In other examples, the clamping plate 375 can be configured to be reflective or to include a reflective coating so as to improve optical efficiency by redirecting light 380 in a direction normal to a reflective surface 376 of the curved clamping plate 375. Furthermore, the curved shape of the reflective surface 376 of the clamping plate 375 directs a mounting hole 377 and a corresponding fastener 378 laterally, toward the bezel rim 302 of the third example luminaire 300. As a result, the base 301 can include less material (e.g. in the bottom portion 305) and the LED circuit board 108 can be secured to the base 301 without the need to make blind tapped holes beneath the LED circuit board 108. The clamping plate 375 thus also contributes to the low-profile design of the third example luminaire 300. In still other embodiments, the clamping plate may serve as a ground path for any electronics of the luminaire 300 or LED circuit boards 108.
Turning to
As shown in
For example, any one or more of the first example luminaire 100, the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400 can have an outermost dimension (e.g. a height 475 measured from a first outermost point on a first side to a second outermost point on a second side that is opposite the first side) of less than about two inches. In other examples, any one or more of the first example luminaire 100, the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400 can have an outermost dimension (e.g. height 475) of less than about two inches such that an overall profile with respect to a height of any one or more of the first example luminaire 100, the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400 fits within (e.g. entirely within) an area or space defined by the outermost dimension. For purposes of this description, the outermost dimension (e.g. height 475) of any one or more of the first example luminaire 100, the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400 is defined as a distance in a direction orthogonal to an outermost face of the surface 700 to which the any one or more of the first example luminaire 100, the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400 are mounted.
As noted, an outermost dimension can refer to a largest dimension of a component in a particular direction, such that all dimensions of the component with respect to that particular direction are less than or equal to the largest dimension. Thus, in some examples, the outermost dimension may define an overall profile dimension with respect to a particular direction within which a component can fit. For example, any one or more of the first example luminaire 100, the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400 with an outermost dimension of less than about two inches can refer to any one or more of the first example luminaire 100, the second example luminaire 200, the third example luminaire 300, and the fourth example luminaire 400 having an overall profile configured to fit within an area defined with respect to at least one particular dimensional direction by the outermost dimension of less than about two inches.
While various features and aspects are presented above, it should be understood that the features may be used singly or in any combination thereof. Further, it should be understood that variations and modifications may occur to those skilled in the art to which the claimed examples pertain. The examples described herein are exemplary. The disclosure may enable those skilled in the art to make and use alternative designs having alternative elements that likewise correspond to the elements recited in the claims. The intended scope may thus include other examples that do not differ or that insubstantially differ from the literal language of the claims. The scope of the disclosure is accordingly defined as set forth in the appended claims.
It is also to be noted that the phrase “at least one of”, if used herein, followed by a plurality of members herein means one of the members, or a combination of more than one of the members. For example, the phrase “at least one of a first widget and a second widget” means in the present application: the first widget, the second widget, or the first widget and the second widget. Likewise, “at least one of a first widget, a second widget and a third widget” means in the present application: the first widget, the second widget, the third widget, the first widget and the second widget, the first widget and the third widget, the second widget and the third widget, or the first widget and the second widget and the third widget. Finally, the term “substantially,” if used herein, is a term of estimation.