Abstract: In a power-line-operated current-fed parallel-tuned electronic ballast, power-factor-correction and harmonics-reduction are attained by placing a high-frequency inductor as well as a high-frequeny voltage source in series with the DC output of a bridge rectifier connected with the power line voltage. The DC output is then supplied to a filter capacitor through a high-speed diode, thereby to provide a DC voltage of substantially constant magnitude to the ballast's inverter while at the same time drawing power from the power line with a power factor well over 90% and with a total harmonics content well under 20%. The AC voltage provided from the high-frequency voltage source, which has a peak-to-peak magnitude essentially equal to that of the power line voltage, is represented by a simple auxiliary winding on the ballast's main output transformer.

Abstract: A light that meets Federal Aviation Administration requirements for marking powerlines or powerline support structures that is powered from the magnetic field created by the conduction of electricity along a powerline. The energy in the naturally occurring magnetic filed induces an electric current in a specialized coil within the device that delivers a constant voltage to a lamp. The lamp is focused through a lens into the beam pattern required for marking powerline support structures.