Starter circuit for low power sodium vapour tube - has reactive impedance in series with supply and solid state switch shunting tube

摘要

The starting circuit is for a low power discharge tube and is particularly suitable for sodium vapour tubes. The circuit has two input terminals connected to the alternating mains and two output terminals connected to the tube. There is a reactive impedance (L) connected directly between the input terminal and the output terminal. The tube is shunted by a solid state switch in series with a capacitor (C1). The reactive impedance consists of a ballast inductance and a power factor correction capacitor, which can either be in series with the inductor or shunted across the input.