Abstract:
A portable power supply coupled to a garment, carrying bag, or other apparatus, is adapted for receiving energy at a solar cell or by way of a power input port for operating and charging a portable device. Power is stored within the power supply in one or more batteries or other storage devices. An output of the portable power supply is adapted to be reconfigured so as to be coupled to various types of portable device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of International Application No.: PCT/US 2008/011527 filed on Oct. 5, 2008, which in turn claims the benefit of U.S. Provisional Patent Application No. 60/997,821 filed on Oct. 5, 2007, the disclosures of both being incorporated herewith by reference in their entireties. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a power supply, and more particularly to a power supply for charging an external storage device. 
       BACKGROUND 
       [0003]    Small electronic portable appliances such as cellular phones, compact entertainment devices, hand held “palm” computers, GPS navigation devices, and small wireless communication equipment have become extremely popular with people of all ages, genders, and locations. 
         [0004]    Generally these devices use electrical power to operate. As portable devices they are not connected to the power utility outlets, but instead use batteries as a power source. An ever increasing percentage of these appliances use rechargeable batteries or other rechargeable storage devices. Unlike regular batteries which are replaced with new batteries when they run out of power, while the used batteries are disposed of, rechargeable batteries can be recharged from an external power source, again and again, and need not be replaced. 
         [0005]    Recharging of portable appliances is typically done by connecting such portable appliances to a power supply which is, in turn, connected to a residential power utility or to an automotive power outlet so as to receive power for the rechargeable batteries. These power sources are not portable and, therefore, while the batteries of the small portable appliances are being recharged the appliances are stationary and not portable. On the other hand if the batteries of the small portable appliances are not recharged periodically, they run out of charge. This renders the portable appliances useless. 
       SUMMARY OF THE INVENTION 
       [0006]    To make such small portable appliances really portable and usable everywhere without a need to recharge the batteries of these portable appliances from the power utilities or automotive power outlets, the inventor is harnessing the power of the sun. 
         [0007]    In daily life many people carry handbags and backpacks in which they store and carry personal items such as money, documents, books, cosmetics items, and small portable electronic appliances. 
         [0008]    According to this invention, carrying apparatus such as personal backpacks and handbags are fitted with a photovoltaic device such as a solar panel to convert solar energy into electrical power to operate a special battery charging apparatus capable of charging the batteries of portable electronic appliances. This enables such a backpack or handbag to simultaneously charge and use the small portable appliances while carried around wherever the user carries the backpack or handbag. In certain embodiments, the photovoltaic cell electrical power source includes a photovoltaic cell; a low light detector; an output switch; a detector comparator; a reconfigurable switch and two or more rechargeable batteries. The batteries are adapted to be alternately connected in series and parallel according to a condition of the reconfigurable switch. The power source has, in certain embodiments, an output including two wires terminating at a connector. In certain embodiments, the photovoltaic device and power supply are supported by and/or integral with a carrying apparatus. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  shows, in block diagram form, a portion of a power supply according to one embodiment of the invention; 
           [0010]      FIG. 2  shows, in block diagram form, an exemplary adapter device according to one embodiment of the invention; and 
           [0011]      FIG. 3  shows, in perspective view, a carrying case including a photovoltaic device and device under charge, forming a system according to one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    The present invention is to be understood with reference to  FIGS. 1 ,  2  and  3 . As illustrated, a photovoltaic (solar) cell  10  connects to rechargeable batteries  16 A and  16 B via a diode  13 . One of skill in the art will appreciate that other rechargeable devices such as, for example, a capacitive charge storage device, can also be employed in the present invention. When the solar cell  10  is exposed to light, it generates an electrical current. Due to the internal resistance of the solar cell  10 , the electrical current, generated as a result of exposure to light, causes the voltage at the positive output pin of the solar cell  10  to increase above the voltage across the battery  16 . Under these conditions, the current generated in the solar cell  10  can flow through the diode  13  to charge the battery  16  ( 16 A and  16 B). 
         [0013]    The voltage across the battery  16  is a property of the chemistry of the battery and the charge in the battery. The chemistry determines the nominal voltage on the battery while the charge in the battery can change the voltage across the battery by as much as 20%. For example, the typical nominal voltage on a Nickel Cadmium battery is 1.2V, but it may be as low as 1.15V when the battery is discharged, and as high as 1.4V when such battery is fully charged. 
         [0014]    When a voltage higher than the nominal voltage of a battery is desired, two or more batteries can be connected in series to yield an overall voltage which is the nominal voltage multiplied by the number of batteries connected in series. 
         [0015]    The charger  200  is designed to continuously charge the portable electronic appliance  100  connected to the charger  200 . However, charging the appliance  100  when intensity of the light to which the solar cell  10  is exposed is too low, may deplete the battery  16  of its charge, causing improper operation of the charger  200 . Two circuits are used here to prevent the battery from being over discharged. One is such that when the solar cell  10  output is insufficient to charge the battery  16 , the low light detection comparator  11  will control the output switch  21  to the OFF state, which will disconnect the charge current to the external appliance  100 . One of skill in the art will appreciate that output switch  21  will, in certain embodiments, be implemented as a solid-state switching device such as, for example, a transistor. Consequently, when the light onto the solar panel  10  is of sufficient intensity to overcome the predetermined set-point voltage at the comparator input  11 , the comparator  11  will change its state, and the output switch  21  will again be controlled to the ON state, completing the circuit and enabling the charge current to the external appliance  100 . A green LED  22  will serve to indicate that the charger  200  has sufficient charge and is currently capable of charging an external appliance  100 . The other circuit section consists of the battery under-voltage detector  15 . This circuit&#39;s function is to prevent the over-discharge of the battery  16 . Over discharging can be harmful to the longevity of the battery  16 , if the battery remains in this discharged condition for long periods. This circuit monitors the voltage at the battery  16 . If the voltage across the battery  16  falls below the preset low level threshold voltage, in this case, the detector/comparator  15  will control the output switch  21  to the OFF state, subsequently disconnecting the external appliance  100 . A red LED  23 , connected to the under-voltage detector  15 , when illuminated, will serve to indicate that the battery  16 , has reached a predetermined low level, and now the charger  200  is not currently capable of charging an external appliance  100 . When the battery  16  voltage is again of sufficient level to reset the state of the comparator  15 , the output of the comparator  15  will control the output switch  21  to its ON state, thereby allowing the charger to charge the external appliance  100 . Consequently, the green LED  22 , connected to the output of the detector  15 , will illuminate to indicate that the battery  16  has been sufficiently charged and the charger  200  is now capable of charging an external appliance  100 . 
         [0016]    The low battery detector circuit  12  alerts the user as to the state of the battery  16  charge. When the battery  16  voltage falls below a predetermined set-point, the low battery detection circuit  12  will change state, and will cause to illuminate a yellow LED  14 . When illuminated, this will serve to alert the user as to the approaching discharged condition of the battery  16 , and the user can then take the necessary action to recharge the battery  16 . 
         [0017]    When the solar cell  10  is exposed to sufficient intensity of light, the voltage generated by the solar cell  10  is no longer lower than that of the battery  16 , and the under voltage detector  15  turns ON controlling the output switch  21  to ON state. Consequently, the green LED  22 , connected to the output of the detector  15 , will illuminate to indicate that the charger  200  is now capable of charging an external appliance  100 . 
         [0018]    External charge port  24  allows for supplemental charging of charger  200  from other sources when sunlight is unavailable, such as at night or when indoors under low light conditions. The charge port  24  consists of a USB mini-B connector that is compatible with industry standard USB format. Using an appropriate cable, the charger  200  can be charged via any personal computer that is equipped with a USB port. Charging can also be applied to this port  24  with any wall transformer type appliance that is specifically designed for this purpose. Current from the USB connector input source is coupled to the battery  16  through diode  25  and current limiting resistor  26 . 
         [0019]    Switch  27  is used to select the appropriate charge source to the battery  16 . In position  1 , the switch  27  will configure the battery(s)  16  so as to charge in parallel. This allows the battery  16  to charge from the lower voltage of the USB sourced input. This position also serves to disable the operation of the charger  200 , while charging the battery  16 . Position  2  of switch  27  also has 2 functions. One function is to enable charger  200  operation. The other function is to reconfigure the battery(s) in series so as to have sufficient voltage to charge an external device  100 . 
         [0020]    The charger  200  output circuit is protected by a resettable fuse  28 . If the output of the charger  200  is shorted, or if there is a problem with the external device  100 , causing the current from the battery  16  to increase beyond a preset set point, the resettable fuse  28  will be heated causing the resistance of the resettable fuse  28  to increase. This will limit the current from the charger  200  to a safe value, preventing damage to the charger  200 , or the external device  100 . When the cause of the short, or the external device  100 , is disconnected from the output of the charger  200 , the resettable fuse  28  will cool, and the resistance of the resettable fuse  28  will decrease to a normal value, allowing the charger  200  to again be ready to charge an external device  100 . 
         [0021]    In certain embodiments, the invention includes a kit having a power supply and one or more adapter devices. For example, in one embodiment, the kit includes a first iPhone® adapter and a second iPod® adapter ( FIG. 2 ). By connecting the adapter to the output of the power supply, a custom configuration of the power supply is provided. This configuration allows for the charging of the iPhone® and iPod® from the charger  200 . In the illustrated embodiment of  FIG. 2 , the adapter is internally configured with 4 biasing resistors. These resistors are connected in such a manner so as to apply a low bias voltage to the USB Data (+) and USB Data (−) connections. Power for the biasing is derived from the charger  200  power source connection. 
         [0022]      FIG. 3  shows, in perspective view, a charging system including a luggage article according to one embodiment of the invention. In the illustrated embodiment, the luggage article is a backpack  1 . A photovoltaic cell  3  is coupled to an external surface of the backpack  1 . An electrical conductor  4  is provided to convey power from a power supply to a portable device  2 . The power supply is disposed within the backpack and coupled to both the photovoltaic cell  3  and electrical conductor  4 . 
         [0023]    While reference is made in the above examples to batteries such as, for example, electrochemical batteries, one of skill in the art will appreciate that the invention may, according to its principles, be applied to a wide variety of other energy storage devices including, without limitation, capacitive energy storage devices, pneumatic energy storage devices, and mechanical energy storage devices, according to the requirements of any particular application. In addition, while reference is made to a photovoltaic or solar cell for receiving energy, one of skill in the art will appreciate that alternative devices and means for receiving energy such as, for example, a microwave energy receiver, would also fall within the scope of the invention. Further, one of skill in the art will appreciate that the principles of the invention are equally well applied, and that the benefits of the present invention are equally well realized in a wide variety of other systems. Therefore, while the invention has been described in detail in connection with the presently preferred embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.