Abstract: A low-loss sinusoidal drive system is disclosed for powering thin-film electroluminescent displays (TFEL). A DC power source coupled through a DC-to-AC inverter and driving an LC resonant tank circuit is used to produce a sinusoidal supply voltage. The sinusoidal supply voltage is coupled to produce a sinusoidal backplane driving voltage and coupled to a synchronizer circuit which controls drive logic for selectively energizing segments of the TFEL display. The drive logic is coupled to respond to an on-off command for selecting a particular segment such that the average DC voltage across a segment of the TFEL is zero, independent of the on/off condition of the segment. The backplane sinusoidal voltage may be applied in common to multiple TFEL devices with the synchronizing and drive logic circuits individually selecting the segments for TFEL drive.