Patent Application
20090278458
1. Technical Field
The present invention relates to lighting devices and, particularly, to an outdoor lighting device with LED arrays.
2. Description of Related Art
Light emitting diode (LED), a solid state light emitting element, has been widely used in lighting.
An LED is capable of producing a visible light in a certain wavelength if an electric power is applied to the LED. However, 80% to 90% of the electrical energy consumed by the LED is converted to heat, which needs to be dissipated, and only the small remainder is converted to the light.
When a plurality of LEDs, such as an LED array is used at outdoors, it is usually difficult to power the LED array and dissipate heat for it.
What is needed, therefore, is an outdoor lighting device, which overcomes the above problems.
An outdoor lighting device includes a first LED array, a second LED array, a first electric power supply system, a heat conducting substrate and a second electric power supply system. The first LED array is capable of working at a first time when a natural wind blows. The first electric power supply system includes a fan and an electric power generator. The electric power generator is mechanically connected to the fan and configured for converting the kinetic energy of the fan into electric power for the first LED array. The second LED array is arranged adjacent to the first LED array. The second LED array is capable of working at a second time when the first LED array does not work. The heat conducting substrate is attached on the second LED array. The second electric power supply system includes a solar cell panel for converting solar energy into electric power for the second LED array. The solar cell panel is arranged above the heat conducting substrate, and a space exists between the solar cell panel and the heat conducting substrate so as to facilitate heat dissipation of the heat conducting substrate.
Other novel features and advantages of the present outdoor lighting device will become more apparent from the following detailed description of embodiments when taken in conjunction with the accompanying drawings.
Many aspects of the outdoor lighting device can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present outdoor lighting device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Embodiments of the present outdoor lighting device will now be described in detail below and with reference to the drawings.
Referring to
The first LED array 110 is arranged on a printed circuit board (PCB) 112 and faces the ground. The first electric power supply system 120 mainly includes a fan 122 and an electric power generator 124. In addition, a first battery pack 170 (see
A base 130 and a first elongated post 150 are also included in the first electric power supply system 120. The electric power generator 124, the first elongated post 150, the first battery pack 170 and the first control unit 180 are arranged on the base 130. The fan 122 includes a shaft 122b and three blades 122a attached on the shaft 122b. The fan 122 is mounted at an end of the first elongated post 150 opposite from the base 130. The first LED array 110 is also mounted on the first elongated post 150, between the fan 122 and the base 130.
The electric power generator 124 includes a rotator 124a and a stator 124b. The rotator 124a is mechanically connected to the shaft 122b of the fan 122 by a connection belt 126. Once a natural wind blows, the blades 122a will be blew to rotate, e.g., in a direction as the arrowhead S shows, then the shaft 122b will thus be rotated, and the rotator 124a is driven to rotate in a direction as the arrowhead P shows. The stator 124b generates an electric power when the rotator 124a rotates.
Referring to
When a natural wind blows, the first PMW controller 186 first obtains a voltage signal V1 and a current signal I1 of the first battery pack 170, then outputs a charge signal S1 to activate the AC/DC converter 182 to work. The AC/DC converter 182 then can outputs a direct current to the first battery pack 170 via the first battery charge and discharge controller 184. The first PMW controller 186 outputs a discharge signal S2 to the first battery charge and discharge controller 184, the first battery charge and discharge controller 184 then controls the first battery pack 170 to power the first LED array 110.
When the natural wind disappears, the first LED array 110 will be powered off. In this way, the first LED array 110 works only at the time when the natural wind blows, such that heat generated by the first LED array 110 can be dissipated timely by the natural wind.
The second LED array 250 and the second electric power supply system 220 are mounted on a second elongated post 270. The second elongated post 270 is taller than the first elongated post 150 and is arranged adjacent to the first elongated post 150. The second LED array 250 is mounted on a second PCB 240. Light emitted from the second LED array 250 can project on the ground. The second LED array 250 is arranged over the first LED array 110 and adjacent to the fan 122. The heat conducting substrate 210 is attached on the second PCB 240.
The second electric power supply system 220 mainly includes a solar cell panel 230, a second control unit 280 and a second battery pack 290. The solar cell panel 230 is arranged above the heat conducting substrate 210, and a space 215 exists between the solar cell panel 230 and the heat conducting substrate 210, such that the heat conducting substrate 210 will not be heated by the sunlight, and thus facilitating heat dissipation of the heat conducting substrate 210.
Referring to
In this way, the first LED array 110 and the second LED array 250 work at a different time, the second lighting device 20 can compensate for the first lighting device 10. Heat dissipation and electric power for each of the first LED array 110 and the second LED array 250 are carried out at the same time. The entire outdoor lighting device 100 is environmental friendly and can function effectively.
It is understood that the above-described embodiments are intended to illustrate rather than limit the invention. Variations may be made to the embodiments and methods without departing from the spirit of the invention. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810301421.2 | May 2008 | CN | national |
This application is related to a commonly-assigned co-pending application entitled, “OUTDOOR LIGHTING DEVICE”, filed on Sep. 2, 2008 (U.S. application Ser. No. 12/202588, Docket No. US18948). Disclosures of the above identified application is incorporated herein by reference.
