Abstract:
A light assembly comprising a globe, an electric grid powered lighting element disposed within the globe, a solar powered lighting element disposed within the globe, a solar panel coupled to the solar powered lighting element for collecting light and generating power for the solar powered lighting element, a rechargeable power source coupled to the solar panel and the solar powered lighting element for storing the power generated by the solar panel and powering the solar powered lighting element, a first sensor for detecting an ambient light level and activating the solar powered lighting element when the ambient light level is below a desired ambient light level, and, a second sensor for detecting output levels of the solar powered lighting element and activating the electric grid powered lighting element when the output level of the solar powered lighting element is below a desired output level.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     None. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None. 
     REFERENCE TO A “SEQUENCE LISTING” 
     None. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a solar powered light and more particularly to a solar powered light for providing an alternative or additional light source in a light fixture. 
     2. Description of Related Art 
     Over recent years, there has been volatility in the price of electricity. In addition to price volatility, the use of certain fuels has been found to be harmful to the environment. For example, when electricity is generated from coal, large amounts of carbon dioxide are emitted into the environment, which contributes to poor air quality and global warming. As a result, many are interested in using alternative energy sources which are less expensive and more environmentally friendly. One type of alternative energy source that is becoming increasingly popular is solar power. Solar power is a renewable power source that produces power at a fuel cost of zero and can be used in a variety of settings, including but not limited to residential, municipal and commercial property settings. 
     A problem with solar power, however, is that there is a significant upfront cost associated with obtaining the equipment and components necessary to utilize a solar power system. Thus, although many individuals are interested in utilizing solar power, the upfront expense of switching from the electric power grid to solar power is prohibitively expensive. 
     What is needed then is a solar powered light that can be integrated with or attached to light fixtures connected to the electric grid. 
     BRIEF SUMMARY OF THE INVENTION 
     Certain embodiments of the present invention are directed to a solar powered light for providing an additional or alternative lighting source in a light fixture and provide one or more benefits and advantages not previously offered in the art, including but not limited to a solar powered light that can be added to an existing light fixture. Another advantage of the present invention is that it provides a solar powered lighting option to individuals that do not want to make the initial investment of transferring from the electric grid to solar power. Further, the present invention includes a light fixture having lights powered from multiple power sources. 
     In one configuration, the present invention comprises a light assembly comprising a globe having a lighting element powered by the electric grid and a solar powered lighting element. A solar panel is coupled to the solar powered lighting element and collects light to generate power for the solar powered lighting element. A rechargeable power source is coupled to the solar panel and the solar powered lighting element for storing the power generated by the solar panel and powering the solar powered lighting element. The present invention can include a sensor for detecting an ambient light level. The solar powered lighting element is then activated when the ambient light level is below a desired ambient light level. The present invention can also include an additional sensor for detecting output levels of the solar powered lighting element. The lighting element powered by the electric grid is then activated when the output level of the solar powered lighting element is below a desired output level and when the ambient light level is below a desired ambient light level. 
     The present invention also includes a method of retrofitting a light fixture with a solar powered light comprising attaching a solar powered lighting element to a globe of a light fixture, the light fixture having at least one lighting element connected to an electrical grid power source. Light is collected with a solar panel coupled to the solar powered lighting element and power is generated from the collected sun light. The power generated from the sun light is stored with a rechargeable power source. The ambient light level may be sensed by a sensor and the solar powered lighting element may be illuminated with the power from the rechargeable power source when an ambient light level is lower than a pre-determined ambient light level. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       The foregoing features of this invention, as well as the invention itself, may be more fully understood from the following description of the drawings in which: 
         FIG. 1  is a perspective view of a light fixture having an electrical grid powered light and a solar powered light coupled to a solar panel mounted to a separate structure. 
         FIG. 2  is a perspective view of the light fixture having an electrical grid powered light and a solar powered light coupled to a solar panel mounted to the light fixture. 
         FIG. 3  is a bottom perspective view of the light fixture showing an electrical grid powered light and a solar powered light. 
         FIG. 4  is a top perspective view of the light fixture which is capable of being mounted to an electrical grid power source. 
         FIG. 5  is a bottom perspective view of the light fixture showing an electrical grid powered light, a solar powered light, and an additional solar panel positioned to collect light from the electrical grid powered light. 
         FIG. 6  is perspective view of a free standing light fixture showing an electrical grid powered light and a solar powered light. 
         FIG. 7  is a perspective view of a free standing light showing an electrical grid powered light, a solar powered light and an additional solar panel positioned to collect light from the electrical grid powered light. 
         FIG. 8  is a schematic diagram of an exemplary control circuit for controlling the operation of the various components of an exemplary embodiment of the invention. 
         FIG. 9  is a flow diagram depicting an embodiment of a method of retrofitting a light fixture with a solar powered light. 
         FIG. 10  is a continuation of the flow diagram of  FIG. 9  depicting an embodiment of a method of retrofitting a light fixture with a solar powered light. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred embodiment, it is understood that the invention is not limited to the disclosed embodiment. 
     Furthermore, it is understood that the invention is not limited to the particular methodology, materials, and modifications described and as such may vary. It is also understood that the terminology used herein is for the purpose of describing particular elements only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. 
     Referring to the Figures,  FIGS. 1-5  show a light fixture  10  having a housing  12 , a globe  14 , and lighting element  16  disposed within the globe  14 . The light fixture  10  is connected to an electric grid power source  18 . The light fixture  10  further includes a solar powered lighting element  20  disposed within the globe  14  and connected to a solar power source. That is, lighting element  20  is connected to a solar panel  22  and to a rechargeable power source  24  as discussed in further detail below. The solar powered lighting element  20  provides an alternative or additional lighting source to the lighting element  16  in the light fixture  10 . A sensor  26  is connected to the solar powered lighting element  20  to detect the ambient light levels and activates the solar powered lighting element  20  when the ambient light levels are below a certain desired level. In one configuration, a second sensor  28  is connected to the lighting element  16  and activates the lighting element  16  when the ambient light level is below the desired level and when the solar powered lighting element  20  is lower than a desired minimum light output level. 
     The light fixture  10  can be any type of configuration wherein a lighting element  16  is contained within a globe  14 . By globe  14 , it is meant that the light fixture includes a portion that at least partially covers the lighting element  16  and is coupled to a single electric grid power source. For example, the globe  14  may be any type of shade, jar, can, diffuser, or any other type of glass, plastic, metal light housing that is coupled to a single electric grid power source. In one configuration, the light fixture  10  is an outdoor light for residential, municipal, or commercial purposes. For example, the light fixture may be an outdoor porch light, recreational light, or free standing light. Alternatively, the light fixture  10  can be located within a naturally-lit indoor area. Typically, the electrical grid powered light fixture  10  is connected to the electrical grid by wires to receive power. The electrical grid powered lighting element  16  can be operated by a switch, for example, a wall switch, to turn the lighting element  16  on and off. The lighting element  16  is preferably an incandescent light, fluorescent light, including but not limited to compact fluorescent lights and linear fluorescent lights, high intensity discharge lights, halogen light, or light emitting diode (LED) light. It should be appreciated by those having ordinary skill in the art that the lighting element  16  may include just one light bulb or a plurality of light bulbs. 
     As shown in the figures, the lighting element  20  is preferably a solar powered light that is self-powered by the solar panel  22 . The solar panel  22  comprises a plurality of electrically connected photovoltaic cells. A plurality of solar panels  22  can also be used. The solar panel  22  can be mounted proximate to the light fixture, for example on the building structure itself, as shown in  FIG. 1 . In another configuration, as shown in  FIG. 2 , the solar panel  22  is contained within a housing  12  of the light fixture  10 . It should be appreciated by those having ordinary skill in the art that additional solar panels can be used and these modifications are intended to be within the spirit and scope of the invention as claimed. For example, as shown in  FIG. 5 , an additional solar panel  22  can be mounted within the globe  14  to collect light from the lighting element  16  powered by the electrical grid. Thus, if the lighting element  16  is illuminated by power from the electric grid, solar power can be generated from the lighting element  16 . 
     The rechargeable power source  24  is preferably one or more rechargeable batteries of a conventional design, which are capable of storing power that is generated by the solar panel  22  so that it can be used at a later time to power the lighting element  20 . The lighting element  20  is preferably an LED since LED lights are energy efficient and long lasting. However, other types of light elements can be used including, but not limited to, incandescent, halogen, fluorescent and high intensity discharge lights. In an embodiment of the invention, at least one mirror  32  can be operatively positioned within the housing  12  of the light fixture  10  to focus and reflect the light in a preferred direction. 
     The sensor  26  monitors the ambient light levels. The sensor  26  determines whether the transition from day to night has occurred. When the sensor  26  determines that the light level is lower than a pre-determined light level, for example, dusk, the sensor  26  will switch on the solar powered lighting element  20 . When the sensor  26  determines that the ambient light level is greater or equal to the pre-determined light level, the sensor will switch off the solar powered lighting element. 
     The sensor  28  simultaneously monitors the light output level of the lighting element  20 . The sensor  28  determines whether the light output level of the lighting element  20  is lower than a minimum light output level. If the light output level of the lighting element  20  is lower than the minimum light output level, then the sensor will switch on the lighting element  16 . However, the lighting element  20  will only be switched on if the sensor  26  has determined that the ambient light level is lower than a pre-determined light level. 
     It should be appreciated by those having ordinary skill in the art that additional components may be used to increase the light output level of the lighting element  20  as the ambient light level decreases and this modification is intended to be within the scope of the invention as claimed. Further timers or manual switches may also be used to switch on and off the lighting elements  16 ,  20 . 
     The configuration in  FIG. 4  shows that the light fixture  10  can be attached to a pre-existing electrical grid power source for a light fixture to provide a retro-fit light fixture. The light element  20  in this configuration is integral to the light fixture  10 . 
     As shown in  FIGS. 6 and 7 , a pre-existing light fixture  10  can be retro-fit with a solar powered lighting element  20  contained within a housing  30 , wherein the solar panel  22  is disposed on a top portion  32  of the housing  30  and the lighting element  20  is coupled to the bottom portion  34  of the housing  30 . The lighting element  20 , therefore, is positioned within the globe  14 . To attach the housing  30  to the pre-existing light fixture  10 , a hole can be drilled through the housing  12  of the light fixture  10  and the top portion  32  of the housing  30  is disposed on top of the housing  12  of the light fixture  10  and over hole. In a configuration of the invention, one pre-existing light fixture  10  can include multiple housings  30  having the lighting element  20  and solar panel  22 . It should be appreciated by those having ordinary skill that the housing  30  can further include certain other components for powering the lighting element  20  disclosed herein, including but not limited to a rechargeable battery  24 , sensors  26 ,  28  and controller  21 . As shown in  FIG. 7 , at least one additional solar panel  22  can be installed within the globe  14  to collect power from the lighting element  16  when illuminated. Further, it should be appreciated that the housing  12  of the original light fixture  10  can be removed and replaced with a retro-fitted housing  12  having the solar panel(s)  22 , lighting element  20 , battery  24 , sensors  26 ,  28  and controller  21  integrated therein. 
       FIG. 8  is a schematic diagram of an exemplary control circuit  19  for controlling the operation of the various components of an exemplary embodiment of the invention. The control circuit  19  shown in  FIG. 8  controls the operation of various components as will be described in more detail below. 
     While control circuit  19  contemplates a standard 120 volt AC electric grid power source  18 , it should be appreciated by those having ordinary skill in the art that other arrangements that function in substantially the same way may also be employed using either higher or lower voltages, AC or DC, logic levels or the like, as long as the function or functions provided by the circuit of  FIG. 8  are carried out. 
     As shown in  FIG. 8 , the lighting element  16  is connected to the electrical grid power source  18  while the lighting element  20  is connected to the battery  24  which is rechargeable by the solar panel  22 . The lighting elements  16  and  20  are both contained within the globe  14 . 
     The ambient light sensor  26  detects ambient light levels and controls switches  25  and  27 . When the sensor  26  is in an ambient light level that is below a pre-determined ambient light level, the switch  25  is switched to the on position and power flows from the rechargeable battery  24  to illuminate the lighting element  20 . Pre-determined ambient light levels may be, for example, when the sensor  26  is in darkness or at dusk light levels. Sensor  28  detects the output level of the lighting element  20  powered by solar panel  22  and also controls switches  25  and  27 . If the battery  24  does not have enough power stored to power lighting element  20  to illuminate the lighting element  20  to a minimum output level, and if the ambient light sensor  26  determines that the ambient light level is below a pre-determined ambient light level, then switch  27  is switched to the on position and power flows from the electric grid  18  to illuminate the lighting element  16 . Typically, the switch  25  is then switched to the off position. Once the ambient light sensor  26  is no longer below the pre-determined ambient light level, switch  25  and/or switch  27  are switched to the off position. In one configuration, the battery  24  can be at least partially recharged when the solar panel  22  collects light from the lighting element  16 . A charge controller  21  is preferably wired between the solar panel(s)  22  and the battery  24  to monitor and control the current from the solar panel(s)  22  and to shut the power off when the battery  24  is fully charged to prevent over-charging and damage to the battery  24 . In one configuration, a resistor  23  limits the amount of current directed to the lighting element  20  and controls the brightness of the lighting element  20 . The amount of light produced by the lighting element  20  can be increased or decreased by increasing or decreasing the amount of current used to power the lighting element  20 . An additional solar panel may be added such that one solar panel collects light from the sun light and another solar panel collects light from the lighting element  16  when lighting element  16  is illuminated. 
     Referring to  FIGS. 9 and 10 , an embodiment of a method of retrofitting a light fixture with a solar powered light is depicted. Generally, according to step  100 , the solar powered lighting element  20  is attached to the light fixture  10  that has at least one lighting element  16 , which lighting element  16  is connected to the electrical grid power source  18 . Then, a solar panel  22 , which is connected to the lighting element  20  and the rechargeable power source  24  collects light according to step  102 . Power is generated from the sun light by the solar panel  22  as set forth in step  104 . The rechargeable power source  24  is used to store the power generated by the solar panel  22 , as set forth in step  106 . According to step  108 , the sensor  26  senses the ambient light level and, as set forth in step  110 , determines whether the ambient light level is lower than a predetermined ambient light level. If the ambient light level is lower than a pre-determined ambient light level, the solar powered lighting element  20  is illuminated as set forth in step  114 . As set forth in step  112 , if the ambient light level not lower than a pre-determined ambient light level, the solar powered lighting element  20  then the solar powered lighting element  20  is not illuminated. 
     According to step  116 , an output light level of the solar powered lighting element  20  is also sensed by a sensor  28 . As set forth in step  118 , the sensor determines whether the output light level of the solar powered lighting element  20  is lower than a predetermined minimum output level. If the output light level of the solar powered lighting element  20  is not lower than a predetermined minimum output level, then the lighting element  16  connected to the electrical grid power is not illuminated as set forth in step  120 . If the output light level of the solar powered lighting element  30  is lower than a predetermined minimum output level, and the ambient light level is lower than a pre-determined ambient light level as previously determined in step  110 , then the lighting element  16  connected to the electrical power grid  18  is illuminated. 
     Although the present invention has been described in terms of particular embodiments, it is not limited to these embodiments. Alternative embodiments, configurations or modifications which will be encompassed by the invention can be made by those skilled in the embodiments, configurations, modifications or equivalents may be included in the spirit and scope of the invention, as defined by the appended claims.