Abstract: A system includes a switching transistor that provides a current source to a load when activated by an input voltage and at least one Zener diode connected in parallel with the load that acts as a shunt regulator. The system may be especially suited for matching the controlled luminance of light emitting diodes to the controlled luminance of incandescent lighting. The system may also be useful for displays where a single master voltage regulator switch or controller controls the different types of lighting. The system may be packaged in a chip scale package for compactness, reduced weight, cost effectiveness, and higher efficiency and reliability.

Abstract: An exercise treadmill machine is provided in which an optical sensor monitors the position of a user on the treadmill and automatically varies the speed of the treadmill to keep the user near a predetermined position on the treadmill's endless belt. The optical sensor preferably includes an infrared (IR) emitter and an IR detector which are located in or near the treadmill control panel that also houses a preprogrammed microprocessor. The microprocessor controls the speed of the belt as required to adjust for variations in the position of the user.