Abstract: A self-contained, rechargeable LED flashlight uses a zener diode in reverse-breakdown avalanche mode as a low-cost voltage regulator. A second embodiment of the LED flashlight incorporates boost-buck circuitry to allow the internal rechargeable flashlight battery to be recharged through external dry cells. An LED or LED array of the flashlight may be by passed with operator control to allow an internal battery to operate an external device, such as a cellular telephone or the like.

Abstract: A low cost fiber optic lighting display system includes a light source, an electronic shutter having independently controllable pixel elements positioned proximate to the light source, a controller for controlling the pixels, and a plurality of optical fibers, each fiber having input and output ends with the input end of each fiber positioned proximate to the output side of a pixel element or group of pixel elements. The corresponding method includes providing a fiber optic lighting display having a light source, an electronic shutter having independently controllable pixels, a controller connected to the electronic shutter for controlling the pixels, and a plurality of optical fibers, each optical fiber having an input end positioned proximate to a pixel or group of pixel elements and an output end.

Abstract: A micro-controller and a converter circuit provide constant current to light emitting diode array from a power supply with greater voltage than the forward bias voltage of the light emitting diode. A micro-controller operatively coupled with a semiconductor switch and the converter circuit measures the ability of a DC power supply to charge the inductor. Duty cycles of the semiconductor switch are modified according to the measurement of the voltage across the internal resistor of the semiconductor switch so as to supply substantially constant current to the LED array through an inductor regardless of actual battery voltage.

Abstract: A mirco-controller and boost converter circuit provide constant current to light emitting diode array. A micro-controller operatively coupled with a semiconductor switch and the boost converter circuit measure the ability of a DC power supply to change the inductor. Duty cycles of the semiconductor switch are modified according to the measurement so as to supply substantially constant current to the LED array through an inductor regardless of actual battery voltage.