A drive circuit for delivering an AC voltage to an array of electro-luminescent lamps (8a to 8n) includes a single coil (1), the energy in which is transferred to each lamp through a corresponding switch assembly (10a to 10n) having positive and negative-going paths for conducting positive and negative voltages to the corresponding lamp. The magnitudes of the voltages applied to the parallel-connected lamps are controllable so that the illumination levels of the lamps are individually adjustable.