Patent Application
20140246986
The present disclosure relates to light emitting diode (LED) lighting devices and lighting systems using LED lighting devices.
Typically, a LED lighting device includes a regulated AC/DC power supply that converts an AC power input into a low-voltage DC output used for powering LED elements of the device. The present disclosure provides improvements vis-a-vis the state of the art.
A DC-powered LED lighting device and a lighting system using such LED lighting devices are disclosed.
In one embodiment, the LED lighting device can include a DC/DC converter, a LED driving circuit, and one or more LED assemblies. The LED lighting device is DC-powered using a first DC voltage V1. The DC/DC converter converts the DC voltage V1 into a second, lower DC voltage V2, which is used by the LED driving circuit for powering the LED assemblies.
In accordance with another aspect, the disclosure provides a system for powering the aforementioned LED lighting devices. This system includes an AC/DC power supply that is configured to be coupled to an AC electrical main, wherein the AC/DC power supply converts AC input power into DC output power at the DC voltage V1, where the voltage V1 is a DC voltage that is higher than the peak of the AC sine wave from the electrical main. The system further includes one or more of the aforementioned LED lighting devices, and a DC high voltage circuit that selectively energizes the LED lighting devices using power from the AC/DC power supply. In an exemplary embodiment, the DC voltage V1 can be higher than the voltage in the electric main.
Various other aspects and embodiments of the disclosure are described in further detail below. It has been contemplated that features of one embodiment of the disclosure may be incorporated in other embodiments thereof without further recitation.
The Summary is neither intended nor should it be construed as being representative of the full extent and scope of the present disclosure. All objects, features and advantages of the present disclosure will become apparent in the following detailed written description and in conjunction with the accompanying drawings.
The novel features believed being characteristic of the description are set forth in the appended claims.
The images in the drawings are simplified for illustrative purposes and are not depicted to scale. To facilitate understanding, identical reference numerals are used in the drawings to designate, where possible, substantially identical elements that are common to the figures, except that alphanumerical extensions and/or suffixes may be added, when appropriate, to differentiate such elements.
For purposes of illustration, and not limitation, referring to
The input terminal 110 is configured for coupling the LED lighting device 100 to a DC circuit 220 (shown in
In some embodiments, in addition to conducting DC current to the converter 120, at least some contacts of the input terminal 110 may be adapted for conducting control/feedback signals used by the control module 160. In alternate embodiments, the input terminal 110 may have additional contacts for conducting at least a portion of such signals. In yet further embodiments, the control/feedback signals may, at least win part, be transmitted to/from the LED lighting device(s) 100 using wireless data transmission techniques (e.g., WiFi, Bluetooth, RFID, and the like), as illustrated in
The DC/DC converter 120 can be a general-purpose DC/DC converter (e.g., a DC/DC power supply including a step down transformer) that is configured to convert input DC power at the DC voltage V1 into output DC power at the DC voltage V2, which is used by the LED driving circuit(s) 130 for powering the LED assembly/assemblies 140. The power rating of the DC/DC converter 120 can be selected appropriately based on the power requirements of the particular driving circuits and LED assemblies used in a particular application.
In alternate embodiments that are not specifically illustrated in the Figures, the DC/DC converter 120 may include series or parallel networks of component DC/DC converters. DC/DC converters may be connected in series, as desired, in order to operate as step-down units that reduce, in steps, the DC voltage V1 to the DC voltage V2, as well as provide one or more intermediate DC voltages V3, where V3<V1 and V3>V2. Correspondingly, DC/DC converters may be connected in parallel, for example, to be used for the selective powering of particular LED driving circuits 130, the illumination-enhancing devices 150, or the control module 160.
In some implementations, the DC voltage V1 is higher than the DC voltage V2. For example, in some LED lighting devices 100, the DC voltage V1 can be, for example, about 350-400 VDC, Hand the DC voltage V2 can be about 12-90 VDC. In other implementations, the DC voltage V1 can be selected in a range from about 100 to about 600 VDC. This can result in relatively lower ohmic losses in the higher voltage lines, as the current is correspondingly reduced for a given amount of electrical power. If desired, however, the DC voltage V1 may also be equal or substantially the same as V2.
The LED driving circuit 130 is preferably an electronic module that regulates the light output of the LED lighting device 100 by providing and controlling electric power (e.g., voltages, currents and timing of applied voltages) to the LED assembly (or assemblies) 140. In some embodiments, the LED driving circuit 130 can be a stand-alone module or may alternatively be an assembly of component modules, such as wired or printed circuit boards (PCBs), integrated circuits (ICs), or a combination thereof.
Additionally or alternatively, the LED driving circuit 130 may receive commands from and/or provide feedback signals to the control module 160, as well as incorporate portions thereof. Functions of the control module 160 can include, for example, at least one of (i) turning the LED lighting device 100 on or off, (ii) changing or modulating the intensity or color scheme of the produced illumination, (iii) performing in-situ optical, electrical, or mechanical adjustments, and (iv) reporting on operational status/performance of components of the lighting device 100.
In some embodiments, the LED driving circuit 130 can also operate the illumination-enhancing devices 150 or portions thereof. The devices 150 generally include optical, electrical, or electro-mechanical devices enhancing or controlling optical properties or power consumption of the LED lighting device 100, such as dimmers, switches, and mechanisms for engaging/replacing lenses or optical filters or adjusting spatial/angular orientation of individual LEDs or groups of LEDs in the LED assemblies 140, among other devices.
The LED assembly 140 generally includes one or more LEDs or one or more groups of the LEDs electrically arranged as one or more series networks, parallel networks, or a combination of series and parallel networks of LEDs. Additionally, in some embodiments, the LED assembly 140 may include portions of the illumination-enhancing devices 150.
For purposes of illustration, and not limitation, referring to
The AC/DC power supply 210 includes an AC input terminal 212 and an DC output terminal 214. The AC/DC power supply 210 is coupled to an electric main 202 (e.g., operated by a local utility) by way of the AC input terminal 212. In operation, the AC/DC power supply 210 converts input AC power from the electric main 202 into DC output power at the DC voltage V1 (discussed above in rev. to
In most public, commercial, industrial, and residential lighting applications, the electric main 202 typically supplies AC power (e.g., 3-phase AC power) provided by way of various wiring schemes (e.g., Delta, Wye, etc.), as desired. It will be appreciated by those of skill in the art that the AC/DC power supply 210 may be coupled to the electric main 202 by way of other configurations.
Generally, the AC/DC power supply 210 is a regulated power supply producing a pre-determined, conditioned DC output (e.g., voltage/current stabilized output, voltage/current limited output, filtered/surge protected output, and the like). However, win some applications, the AC/DC power supply 210 may be an unregulated or partially regulated (e.g., voltage-limited) AC/DC power supply. In some embodiments, the AC/DC power supply 210 may be reduced to practice as an assembly of individual functional modules.
The LED lighting devices 100 can be selectively connected, by way of the DC circuit 220, to the output DC terminal 214 of the AC/DC power supply 210. A use in the LED lighting system 200 of a common power source (i.e., the AC/DC power supply 210), as well as powering of the LED lighting devices 100 using DC voltages allow to increase power efficiency and reduce operating and equipment costs of the LED lighting system 100. Additionally, power efficiency of the LED lighting system 200 is increased by using of the DC voltage V1 higher than the RMS (root mean square) values of line or phase voltages in the electric main(s) 202.
In one preferred embodiment, the AC/DC power supply 210 provides, at the output terminal 214, a regulated output at the DC voltage V1 that is selected to be higher than or close to an amplitude of phase voltage VL−N or an amplitude of line voltage VL−L in the electric main(s) 202. Herein, the phase voltage VL−N is defined as voltage between a line conductor and a neutral conductor of the electric mains 202, and the line voltage VL−L is defined as voltage between two line conductors of the electric mains 202. It is preferred that V1 be higher than the peak of the AC sine wave in the electrical main. However, in lighting systems employing multiple LED lighting devices (e.g., lighting systems of public, commercial or industrial settings), such an approach can lead to power inefficiency and equipment redundancy. However, in lighting systems employing multiple LED lighting devices (e.g., lighting systems of public, commercial or industrial settings), such an approach can lead to power inefficiency and equipment redundancy.
In some applications, the AC/DC power supply 210 can be coupled to the electric main(s) 202 operating at the phase voltage VL−N=110-277 VAC or at the line voltage VL−L=230-347 VAC commonly used in the USA and other countries. In these applications, the DC voltage V1 is typically selected in a range of about 350-400 VDC.
However, in other embodiments of the LED lighting system 200, the DC voltage V1 may be either higher or lower than amplitudes of the corresponding voltages VL−N or VL−L of the electric means 202 (e.g., up to 100% higher or up to 50% lower than the voltages VL−N or VL−L). In yet other embodiments of the LED lighting system 200, the DC voltage V2 may be higher than the voltages V1, VL−Nor VL−L.
In alternate embodiments of the LED lighting system 200, a value of the DC voltage V1 may be selected independently from the values of the voltages VL−N or VL−L. For example, the DC voltage V1 may be selected in a range from 100 to 600 VDC. Correspondingly, the DC voltage V1 may be selected independently from a wiring scheme (e.g., Delta, Wye, etc.) of the electric main(s) 202 or a number of power/neutral lines thereof coupled to the AC/DC power supply 210.
The DC circuit 220 generally includes electrical wiring that rated to conduct electricity at the DC voltage V1. As such, the DC circuit 220 preferably matches or exceeds, with industry-required margins, output current and output voltage ratings of the AC/DC power supply 210. For coupling to the LED lighting devices 100, the DC circuit/wiring 220 may be provided with industry-standard or custom interconnect terminals, such as socket-type terminals, plug-type terminals, clamp-on terminals, wired-type terminals or track-mountable terminals, among other types of electric terminals. In some applications, in settings being illuminated using the LED lighting system 200, portions of existing AC wiring may meet the requirements for the DC wiring 220. This can facilitate the retrofitting of old lighting systems for a building with lighting systems as described therein.
In accordance with further embodiments, the controller 230 can communicate with the LED lighting device(s) 100 by generating control signals that are then selectively directed to the control modules 160 (discussed in ref. to
Although the present disclosure herein has been described with reference to particular preferred embodiments thereof, it is to be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. Therefore, modifications may be made to these embodiments and other arrangements may be devised without departing from the spirit and scope of the disclosure.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 61/771931, filed Mar. 3, 2013.
| Number | Date | Country | |
|---|---|---|---|
| 61771931 | Mar 2013 | US |
