ELECTRONIC DIMMING BALLAST

摘要

An electronic dimming ballast has a parallel loaded resonant output circuit plus a combination of pulse width modulation and frequency variation to accomplish the dimming of compact fluorescent lamps. The ballast operates at a fixed frequency throughout a selected range of ligth levels, with dimming control being done completely by duty cycle variation over this range of operation, and then smoothly moves to a variable frequency as the light output moves outside the selected range, with both duty cycle and frequency variation being the means of lamp light output control outside the selected range.