An electronic dimming ballast with bifrequency and fuzzy logic control

This paper presents the analysis and design of a series-resonant parallel-l oaded inverter applied to electronic dimming-ballasts with bifrequency and fuzzy logic control. The analysis Of the ballast is carried out in conjunct ion with the fluorescent lamp represented in a plasma model. The component values of the power stage, as well as two switching frequencies, according to the desired maximum and minimum power levels are, therefore, determined, The power levels in between are controlled by varying the ratio between tw o time intervals for which the two frequencies last, respectively. This mec hanism is achieved by using a fuzzy logic controller (FLC), A ballast proto type with the FLC which is implemented on-an 8-bit microprocessor with a re duced instruction set computer architecture has been built, Experimental me asurements have shown the feasibility of the ballast with the proposed cont rol strategy.