Abstract: A differential driving circuit for powering a light source is disclosed. The differential driving circuit includes a first set of switches and a second set of switches. A first current from a power source flows through the first set of switches to charge a first energy storage element when the first set of switches are turned on. A second current from the first energy storage element flows through the second set of switches to power the light source when the second set of switches are turned on. The differential driving circuit further includes a second energy storage element coupled to the light source in parallel and for providing a differential voltage to the light source.

Abstract: The present invention provides systems and methods to operate a PC as an alarm clock. An IC is provided to monitor the power status of PC and generate an alarm clock event at a preselected time. The alarm clock event includes a variety of operations, for example, powering on or off the PC system or controlling an AM/FM or TV module.

Abstract: The present invention provides a driving circuit for driving a light source. The driving circuit includes a serial-arranged transformers system having multiple primary windings and secondary windings; a first switch conducting current though a first path and a second switch conducting current though a second path. The first path is a first set of primary windings connected in series and the second path is a second set of primary windings connected in series and the first set of primary transformer windings and the second set of primary transformer windings form the dual primary windings of the transformers respectively. Based on the conduction of each switch, a DC voltage source supplies power to the primary windings of the transformers, which in turn powers on the light source connected to the secondary windings of the transformers.

Abstract: A touch-pad digital computer pointing-device, for controlling a position of a cursor appearing on a display screen of a digital computer, senses and resolves respective locations within an active area at which concurrent multi-finger contacts occur. Multi-finger contacts with the active area activate or deactivate a drag-lock operating mode, computer power conservation, and other touch-pad operating characteristics such as the touch-pad's sensitivity to finger contact. The touch-pad also senses a velocity and direction for finger contact with the active area for use in transmitting data to the computer which effects continuous cursor movement across the computer's display screen in a direction fixed by the initial direction of contact movement across the active area. While there is no finger contact with the active area, the touch-pad monitors the active area and adjusts its operation to compensate for changes in the surrounding environment such as changes in temperature, humidity and atmospheric pressure.