A novel single-stage cost-effective electronic ballast for HID lamps with high power factor

High-intensity-discharge (HID) lamps are widely utilized in a variety of lighting circumstances that need high luminance. This paper proposes a single-stage electronic ballast for HID lamps; the ballast offers power factor correction and is acoustic-resonance-free. The presented HID lamp ballast integrates a discontinuous-conduction-mode (DCM) operated bridgeless power factor correction (PFC) converter for shaping the input utility-line current with a high/low-frequency square-wave-driven half-bridge inverter for supplying low-frequency square-wave sources to the HID lamp. The features of the proposed ballast are high power factor, low total harmonic distortion (THD) of the input current, cost-effectiveness, and that it is free of acoustic resonance. This paper analyzes the operational modes, key design guidelines and experimental results of the proposed ballast for a 70W HID lamp operating with HOV-rms input utility-line voltage.