Abstract
In a comparison of the operation of high pressure metal halide lamps, on either sine or square wave supplies lamps have been found to operate satisfactorily using both choke and choke/capacitor ballasts. The dependence of lamp power on supply waveform and ballast type has been measured on 250 W MBI lamps for a supply voltage range of 210-270 V. Analysis of the lamp circuit for square wave supply voltage has been made using the simplifying assumption that the lamp voltage is independent of current. Expressions derived for the current waveforms and the power dissipated in the lamp are shown to agree well with experimental values. Although the analysis is used to predict the behaviour of metal-halide lamps, it is equally valid for other types of discharge lamps.
Get full access to this article
View all access options for this article.