Abstract:
A portable solar power and battery charger system configured to provide power to accessories and recharge batteries for example concurrently, with automatic switch over to batteries in a prioritized manner from multiple input sources, for example in the case of loss of sunlight and for example with the capability of orienting and aligning a solar panel regardless of available sunlight at setup time.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application 61/509,311 filed on 19 Jul. 2011, the specification of which is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    Embodiments of the invention described herein pertain to the field of solar power and battery chargers. More particularly, but not by way of limitation, these embodiments enable a portable solar power and battery charger system configured to provide power to accessories and recharge batteries for example concurrently, with automatic switch over to batteries in the case of loss of sunlight and for example with the capability of orienting and aligning a solar panel regardless of sunlight. 
         [0004]    2. Description of the Related Art 
         [0005]    Devices that require electrical power and which cannot couple to a utility provided power source must obtain power from an external source. One external source is a generator. Another source is an external battery. Yet another source is a solar panel. The problem with a generator is size and the requirement for fuel. This limits this configuration to non-portable scenarios for the most part. The problem with external batteries is that after they are exhausted, they can no longer provide power. The problem with a solar panel is that it only produces power when there is sunlight. 
         [0006]    Known solutions exist which combine a solar panel with a battery to provide a portable power solution. Other known solutions exist to attempt to physically move large solar arrays based to track the sun. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    Embodiments of the invention provide a portable solar power and battery charger system. By collapsing the solar panel, it may be readily carried by hand along with embodiments of the system. For example, embodiments of the invention may be stored in a common carry-on bag for an airplane. The system may be used in remote locations with manually assisted setup for orientation and inclination to enable setup of the solar panel at night or in weather conditions where the sun is not visible. 
         [0008]    The system includes the main components of the battery charger that obtains power from a solar panel via an electrical line to charge at least one battery. The solar panel and/or at least one battery is/are utilized to provide power via an electrical line to any desired accessory (meaning one or more accessories as desired). When the sun is not providing power to the solar panel, at least one battery is utilized to power accessory. When the sun is providing power via the solar panel, then the power may be utilized by the system to charge at least one battery and/or power any desired accessory. Embodiments of the solar panel may include a magnetometer and inclinometer (or any suitable combined device for example), to enable the system to indicate the desired orientation and inclination of the solar panel regardless of the time of day or position of the sun for example. 
         [0009]    Embodiments of the system generally include a power sensing circuit, at least one battery charging circuit electrically coupled with the power sensing circuit wherein the at least one battery charging circuit is configured to electrically couple with at least one battery respectively. The system may further include a summed voltage bus coupled with the at least one battery charging circuit wherein the summed voltage bus is configured to enable the at least one battery to provide power in case of loss of solar power. The system also includes a second power sensing circuit electrically coupled with the summed voltage bus and a direct current to direct current switching voltage regulator coupled with the summed voltage bus. The system utilizes at least one processor coupled with the direct current to direct current switching voltage regulator wherein the at least one processor is configured to control the direct current to direct current switching voltage regulator. 
         [0010]    One or more embodiments include a temperature sensor configured to provide a temperature value wherein the processor is configured to control the at least one battery charging circuit based on the temperature value. This allows for optimal charging so as to not damage the batteries and or to maximize battery life associated with any battery being charged by the system. 
         [0011]    One or more embodiments may include at least one GPS (Global Positioning Satellite) receiver coupled with the processor. The GPS receiver allows for the determination of the location of the system and hence, allows for the determination of the latitude of the system and time of year, which allows for example for a maximum power inclination for the solar panel to be calculated. In addition, the system may include an interface configured to couple with the solar panel that includes a magnetometer and an inclinometer, wherein the processor is configured to utilize time and position information from the GPS receiver, and orientation information from the magnetometer and inclination information from the inclinometer in order to indicate the desired orientation and inclination to set solar panel for maximum power. This capability is independent of the amount of sunlight available at the time of setup, e.g., the system may be set up at night or in weather where the position of the sun is not readily determinable. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  shows an overall logical view of the system. 
           [0013]      FIG. 2  shows a logical view of the main components of the system. 
           [0014]      FIG. 3  shows a detailed architectural view of the circuitry of the system. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Embodiments of the invention provide a portable solar power and battery charger system. In the following exemplary description numerous specific details are set forth in order to provide a more thorough understanding of embodiments of the invention. It will be apparent, however, to an artisan of ordinary skill that the present invention may be practiced without incorporating all aspects of the specific details described herein. Any mathematical references made herein are approximations that can in some instances be varied to any degree that enables the invention to accomplish the function for which it is designed. In other instances, specific features, quantities, or measurements well known to those of ordinary skill in the art have not been described in detail so as not to obscure the invention. Readers should note that although examples of the invention are set forth herein, the claims, and the full scope of any equivalents, are what define the metes and bounds of the invention. 
         [0016]      FIG. 1  shows an overall logical view of the system. System  100  includes the main components of the battery charger that obtains power from solar panel  110  via electrical line  120  to charge at least one battery  130 . Solar panel  110  and/or at least one battery  130  is/are utilized to provide power via electrical line  140  to accessory  150 . More than one solar panel  110  may be coupled to system  100 , for example in parallel to increase the available power, however this is not shown for brevity. When the sun is not providing power to solar panel  110 , at least one battery  130  is utilized to power accessory  150 . When the sun is providing power via solar panel  110 , then the power may be utilized by the system to charge at least one battery  130  and/or power accessory  150 . Embodiments of the solar panel may include a magnetometer and inclinometer  160  (or any suitable combined device for example), to enable system  100  to indicate the desired orientation and inclination of solar panel  110  regardless of the time of day or position of the sun for example. This allows for manual set up of the orientation and inclination of solar panel  110  without sunlight, i.e., in the dark if desired. Alternate power sources  110   a  and  110   b  for example non-rechargeable batteries or AC or DC generator or power supply respectively may be selected to power accessory  150  in a prioritized manner. For example AC or DC generator or power supply  110   b  may be utilized first in priority after which non-rechargeable batteries  110   a  may be utilized, followed by solar panel  110  followed by at least one battery  130 . Any other priority order may also be utilized and programmed into the processor described with respect to  FIGS. 2 and 3  below. 
         [0017]      FIG. 2  shows a logical view of the main components of system  100 , namely charging circuitry, input line  120  from the solar panel, which may include communication interfaces for obtaining orientation and inclination from magnetometer and inclinometer  160  for example. In addition, the main charging unit of system  100  is shown coupled with two batteries  130  having two cells each. The output of system  100  is used to power any desired accessories and any number of interface types may be utilized for output line  140 . 
         [0018]      FIG. 3  shows a detailed architectural view of the circuitry of the system. Embodiments of the system generally include power sensing circuit  310 , at least one battery charging circuit  330  (here four are shown, one for each cell of each battery to be charged), wherein the at least one battery charging circuit  330  is electrically coupled with power sensing circuit  310 . The at least one battery charging circuit  330  is configured to electrically couple with at least one battery respectively (see  FIG. 2  for example). Charging circuit  330  may be implemented as a LINEAR TECHNOLOGY® LT3652HV monolithic 4.95V to 34V battery charger chip or any other suitable battery charger as desired. In one or more embodiments of the invention, the charging circuitry may be “ganged” together in any manner to provide charging and power capabilities as desired. For example, as one skilled in the art will appreciate, system  100  in  FIG. 2  may utilize one or more circuits as shown in  FIG. 3  in parallel as desired to provide more power to the batteries from one or more solar panel. In other embodiments, one solar panel may be coupled to one or more embodiments of the system to charge multiple sets of batteries from only one solar panel. The system may further include a summed voltage bus  340  coupled with at least one battery charging circuit  330  wherein summed voltage bus  340  is configured to enable the at least one battery to provide power in case of loss of solar power. System  100  also includes second power sensing circuit  350  electrically coupled with summed voltage bus  340  and direct current to direct current switching voltage regulator  360  coupled with summed voltage bus  340 . Voltage regulator  360  may be implemented as a LINEAR TECHNOLOGY® LTM4607 high efficiency switching mode buck-boost power supply or any other suitable direct current to direct current regulator as desired. System  100  utilizes at least one processor  370  coupled with direct current to direct current switching voltage regulator  360  wherein at least one processor  370  is configured to control direct current to direct current switching voltage regulator  360 . One or more embodiments of the invention may provide a direct current voltage regulator external to the charging circuitry shown in  FIG. 3 , for example coupled externally to electrical line  140 . This lessens the heat generated within system  100 . This also allows for the greatest level of flexibility in allowing accessories with many different interfaces to couple with system  100 . In addition, electrical line  120  may couple with an auxiliary direct current input port of any interface type (not shown for brevity) to allow for non-rechargeable batteries to be utilized for input power. For example, if there non-rechargeable batteries are available, they may be coupled to the system to completely discharge them before they are discarded. In this manner, any remaining charge in the batteries may be utilized by the system to maximize efficiency of power transfer to batteries  130  or accessory  150 . This direct current input port may also be utilized by the system in a priority fashion to allow the system to interface with an alternating current to direct current energy source, e.g., a generator or voltage outlet, etc., and use energy from that source first before utilizing batteries  130 . Non-rechargeable batteries may be utilized in priority before said batteries  130  for example. Processor  370  can interface with any desired interface. As shown processor  370  can interface with an LED UI or light emitting diode user interface. This is shown a LED Driver associated with processor  370  and LED&#39;s for UI or user interface  380  in the figure. One or more embodiments of the user interface accept user inputs that allow system  100  to set the output voltage on electrical line  140  for example. Other user interface elements such as current load and percentage and/or time of expected battery life may also be shown on the user interface  380 . 
         [0019]    One or more embodiments include a temperature sensor (shown as part of element  370  for brevity) configured to provide a temperature value wherein the processor is configured to control at least one battery charging circuit  330  based on the temperature value. This allows for optimal charging so as to not damage the batteries and or to maximize battery life associated with any battery being charged by the system. 
         [0020]    One or more embodiments may include at least one GPS receiver coupled with the processor (not shown for brevity, but coupled electrically or wirelessly to processor  370 ). The GPS receiver allows for the determination of the location of the system and hence, allows for the determination of the latitude of the system and time of year, which allows for example for a maximum power inclination for the solar panel to be calculated. In addition, the system may include an interface configured to couple with the solar panel that includes a magnetometer and an inclinometer  160 , wherein the processor is configured to utilize time and position information from the GPS receiver, and orientation information from the magnetometer and inclination information from the inclinometer in order to indicate the desired orientation and inclination to set solar panel for maximum power. This capability is independent of the amount of sunlight available at the time of setup, e.g., the system may be set up at night or in weather where the position of the sun is not readily determinable. Other embodiments of the invention may utilize small form factor components including a foldable solar panel  110  that allows for a single self contained portable, “grab and go” package. 
         [0021]    Thus embodiments of the invention directed to a portable solar power and battery charger system have been exemplified to one of ordinary skill in the art. The claims, however, and the full scope of any equivalents are what define the metes and bounds of the invention.