Solar Power Devices for Providing Power to Handheld Devices: Field of the Invention
Battery powered mobile appliances have been booming for years. Examples include power tools, laptop computers and mobile phones. A photovoltaic power supply makes batterypowered appliances more practical for users, since the batteries don't go flat. The idea of a solar bag for PDAs and mobile phones was born to satisfy energy needs while traveling, hiking, climbing, sailing, cruising especially for sales people and businesspersons when electricity is not available. The success of the photovoltaic power supply is largely determined by lighting conditions: outdoors, a device is exposed to solar intensities of up to 1000w/m but indoors, under artificial desktop lighting or outdoors during overcast weather, the value decreases to 100w/m. The cells should provide close to maximum voltage already for very low illumination and for a very small area of cells for cellular phones, laptops and PDAs. These specifications are well met by highefficiency cells exceeding 14-15% efficiency in our devices. We have developed a solar charging device for commercially available PDAs, mobile phones and laptops. The charging device consists of a 9-30 solar cell generator connected in string using black on black technology with an area of 5×12 cm and 1.5 watt related power with a low loss charge controller for the Li-Ion battery in the PDAs and mobile phones, and a 33×33 cm 10w power device for the laptops. The present invention is related to solar power devices, which are capable of performing the conversion of solar energy to electrical energy (photovoltaic principle), and in particular which are useful for providing power to handheld devices, whether indoors (inside of a building or other enclosure) or outdoors (outside of a building or other enclosure).
A. Elazari "Solar Power Devices for Providing Power to Handheld Devices: Field of the Invention", Solid State Phenomena, Vols. 97-98, pp. 115-120, 2004