Rare gas fluorescent lamp lighting apparatus

摘要

There is provided a rare gas fluorescent lamp lighting apparatus (50) including: an input power source (Vin); a transformer (TR) having a rare gas fluorescent lamp (DL) connected to the secondary side (TRs) thereof; a switching element (Q1) connected in series to the primary side of the transformer (TRp); and a drive block (10) to drive the switching element (Q1). The drive block (10) includes: a constant voltage circuit (1) to convert the voltage of the input power source (Vin) into a constant voltage as an output; a constant current circuit (2) to output a charging current according to the voltage of the input power source (Vin); a triangular waveform oscillation circuit (3) to increase and decrease oscillation frequency according respectively to an increase and a decrease in a voltage of the input power source (Vin); and a comparison circuit (4) to transform a triangular waveform outputted from the triangular waveform oscillation circuit (3) into a rectangular waveform with a predetermined duty ratio as an output.