Fluorescent lamps have been widely used for a variety of commercial, industrial, consumer, and other lighting applications including, as an important but non-limiting example, commercial signage since the 1930's. More recently, lamps employing one or more light emitting diodes (LEDs) as the primary source of illumination have created a market for retrofitting signs containing fluorescent tubes with LED-based products or devices. Some of the benefits of LED lighting include, without limitation, reduced energy consumption, longer service life, safer and less hazardous materials, and a less complex and less expensive power supply. The enormous installed base of illuminated signs employing fluorescent tubes makes it desirable to implement LED retrofit products that can be installed directly into the existing fluorescent tube sockets. However, the power source for a fluorescent tube generally includes a ballast to control and limit the flow of current to the fluorescent tube. In contrast, LED lamps are generally powered by a DC power supply that provides a constant or substantially constant supply voltage and/or supply current. As a result, it is not generally feasible to install an LED lamp product in the fluorescent tube socket without disconnecting, modifying, or replacing the power circuit coupled to the socket.
For purposes of this disclosure, the term “conductive” is equivalent to “electrically conductive” unless indicated otherwise and refers to a resistivity less than approximately 10−7 Ω-m. In addition, the term “non-conductive” is equivalent to “electrically non-conductive” unless indicated otherwise and refers to a resistivity greater than approximately 1010 Ω-m.
In accordance with subject matter included herein, a disclosed lighting assembly includes a support structure, also referred to herein as a lamp support, to which one or more LED strings are affixed, whether releasably or otherwise. The lamp support may be configured to connect between a first lighting socket and a second lighting socket. The lamp support may include an electrically non-conductive coupling and first and second conductive support segments. In at least one embodiment, a first end of the first conductive support segment is coupled to a first end of the electrically non-conductive coupling while a first end of the second conductive support segment is coupled to a second end of the electrically non-conductive coupling.
Each LED string may include one or more LED modules and a pair of interconnects collectively referred to herein as an interconnect pair. Each LED module may include one or more LEDs and power circuitry for receiving a supply voltage and providing an operating voltage to the one or more LEDs. The interconnect pair may include a conductive positive interconnect a conductive negative interconnect. Each interconnect may include a fixed end and a free end wherein the fixed end is electrically and mechanically connected to one of the support segments while the free end of each interconnect may be “floating”, i.e., not electrically connected to another structure. In at least some embodiments, the fixed end of the negative interconnect is affixed to the second conductive support segment while the fixed end of the positive interconnect is affixed to the first conductive support segment. If the first conductive support segment is electrically coupled to a positive terminal of a voltage and the second conductive support segment is electrically coupled to a negative terminal of the voltage source, the interconnect pair is configured to convey a supply voltage provided by the voltage source to the power circuitry of each LED module.
The electrically non-conductive coupling may include a centrally positioned spacer located between a first cavity, extending from a first end of the coupling to a first surface of the spacer, and a second cavity, extending from a second end of the coupling to a second surface of the spacer. The first cavity may be configured to receive a second end of the first support segment while the second cavity may be configured to receive a second end of the second support segment. The first support segment may comprise an elongated member having a rectangular or square cross section surrounding a corridor that extends the length of the support segment. Each cavity may comprise an annular void defined by a perimeter portion of the coupling surrounding an interior portion, wherein the annular void is configured to receive an end of a support segment.
Each support segment may have a polygonal cross section that defines a plurality of planar surfaces. One or more LED strings may be affixed to any one or more of the planar surfaces.
Each socket may include a conductive element including a forward contact point and a rearward contact point of the socket. The forward contact point may be exposed or otherwise accessible when the socket is empty, enabling a support segment, or an endcap attached to an end of a support segment, to contact the forward contact point when inserted into the socket. The rearward contact point may be exposed or otherwise accessible at a rearward side of the socket, for connecting to a cable or wire connected to a terminal of a power supply. The rearward contact point of the first socket may be connected to a positive terminal of the power supply and the rearward contact point of the second socket may be connected to a negative terminal of the power supply. In such embodiments, the first contact is biased relative to the second socket when the power supply is activated. The power supply may provide a low voltage and constant current or constant voltage supply signal. The magnitude of the low voltage supply signal may be 12 V, 24 V or another suitable value.
When the first support segment is connected to the first socket and the second support segment is connected to the second socket, the first support segment is biased relative to the second support segment. If the fixed end of the positive interconnect is affixed to the first support segment and the fixed end of the second interconnect is affixed to the second socket, the interconnect pair carries a supply voltage produced by the power supply. The interconnect pair may be routed to each LED module on the LED string and thereby power all of the corresponding LEDs. In this manner, the support segments provide a portion of the interconnection between the power supply and the LEDs, making it unnecessary to employ wires or other discrete interconnects that extend beyond physical dimensions of the support structure.
In direct connection embodiments, the support segments connect directly to the forward contact points in the corresponding sockets. In endcap embodiments, an endcap is attached at each end of the support structure and each endcap includes its own conductive element, also referred to herein as a conductive tab, to electrically couple the support segment to the forward contact point of the socket.
A more complete understanding of disclosed subject matter and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
The LED retrofit assembly 100 illustrated in
The LED support 110 illustrated in
In at least one embodiment, each support segment 112 is a conductive structure or a structure that includes a conductive exterior surface while coupling 150 is an electrical insulator or includes an electrically insulating portion that electrically insulates first support segment 112-1 from second support segment 112-2. While the specific compositions of support segments 112 and coupling 150 may vary, embodiments of support segment 112 include metallic embodiments comprised of aluminum, copper, steel, or another suitable metal as well as alloys thereof. Other embodiments of support segments 112 include highly-doped semiconductor embodiments. Embodiments of coupling 150 include, without limitation, plastic embodiments, including thermoplastic embodiments and thermosetting polymer embodiments, “glass” embodiments including silicon-oxide compound embodiments, ceramic embodiments, and other embodiments of any suitable electrically non-conductive material or compound.
In the LED support 110 illustrated in
The LED retrofit assembly 100 illustrated in
In embodiments suitable for use in LED retrofit applications, sockets 111 include any socket with a physical configuration suitable for receiving and/or supporting any of various fluorescent tube formats well known in the industry including, as non-limiting examples, recessed double contact sockets for T8 or T12 bi-pin or high output (HO) tubes. Each socket 111 may include a conductive element 115 providing a conductive path between a first contact point 118-1 positioned at a first end of the conductive element 115 and a second contact point 118-2 positioned at a second end of each conductive element 115 configured to electrically couple support segment 112 to a corresponding supply interconnect 143. Thus, first socket 111-1 may include a first conductive element 115-1 for coupling first support segment 112-1 to first supply interconnect 143-1, which is in turn connected to a first terminal 141-1 of power supply 140.
The first terminal 141-1 illustrated in
The LED string 120 illustrated in
As illustrated in
Turning momentarily to
Returning to
Each LED 121 may include one or more light-producing elements, compounds, or materials that exhibit a characteristic color when electrically activated. In some embodiments, one or more LEDs 121 may include a single light-emitting material that produces a characteristic color. In other embodiments, some or all of the LEDs 121 include two or more light-emitting materials, each of which produces a corresponding characteristic color. In these embodiments, a characteristic color of LED 121 may reflect a combination of the emitted-light from each of the light-emitting materials. In a 2-color embodiment, each LED 121 includes two light emitting components, the first of which emits a first color and the second of which emits a second color and the combination of the two colors results in a third color that differs from the first color and the second color. As a non-limiting example, each LED 121 may include a first light-emitting elements, which emits a blue or bluish light, and a second lighting-emitting element, which emits a yellow or yellowish light, wherein the combination of the two lights results in a white or whitish light.
The positive fixed point 131-P illustrated in
In at least one embodiment, a first conductive element 115-1 within first socket 111-1 electrically couples first terminal 141-1 of power supply 140, via first supply interconnect 143-1, to first support segment 112-1. Similarly, a second conductive element 115-2 within second socket 111-2 electrically couples second terminal 141-2 of power supply 140, via second supply interconnect 143-2 to second support segment 112-2. In these embodiments, there is a voltage differential, equal to or substantially equal to the supply voltage Vdc, between first support segment 112-1 and second support segment 112-2.
Referring to
The coupling 150 illustrated in
Coupling positive module interconnect 130-P to first terminal 141-1 of power supply 140 and negative module interconnect 130-N to second terminal 141-2 of power supply 140 via interconnect paths that include a support segment 112 of LED support 110 and a conductive element 115 in socket 111, beneficially eliminates the need for wires or other retrofit assembly interconnects that extend beyond the physical boundaries of the support segments 112.
Disclosed subject matter encompasses all changes, substitutions, variations, alterations, and modifications to the examples illustrated in the drawings and described herein that a person having ordinary skill in the art would comprehend. Similarly, where appropriate, the appended claims encompass all changes, substitutions, variations, alterations, and modifications to the examples illustrated and described herein that a person having ordinary skill in the art would comprehend.
Number | Name | Date | Kind |
---|---|---|---|
7871180 | Wu | Jan 2011 | B2 |
9004716 | Ai | Apr 2015 | B2 |
9964289 | Pearson | May 2018 | B2 |
10222052 | Ter-Hovhannisyan | Mar 2019 | B1 |