The main advantages of high-frequency electronic ballasts for high-intensity discharge lamps are high luminous efficacy, small size, lightweight and longer lifetime. This is why high-intensity discharge lamps operating at high frequency are widely used. This paper proposes an approach for designing resonant circuit electronic ballasts controlled by frequency variation for high-intensity discharge lamps. The proposed technique including an AC/DC rectifier, a power factor correction circuit and a DC/AC half bridge inverter. These electronic ballasts offer a wide range of dimming controls and can avoid acoustic resonance. However, under dimming, the electric and photometric characteristics of the lamp change. In order to study these effects under the process of dimming, this work studies the lamp properties by varying both lamp power and operating frequency.

Results of spectral and photometric measurements are presented for pulsed power operated high intensity discharges (HIDs). This investigation is related to the application of a pulsed power supply for pile driving of HID lamps. Specifically, we are interested in controlling the spectral response radiation of visible and ultraviolet (UV) lines for tertiary treatment of water using UV radiation. Simulations based on a physical model of the lamps were conducted. These results relate to the radial temperature, line intensity and electrical properties (voltage, power and conductivity). Good agreement has been found between the results of the simulations and the experimental findings.

In this paper, the dimming effects on the photometric and electric characteristics of high intensity discharge lamps supplied by a low frequency square waveform are evaluated. For this evaluation an electronic ballast is presented. The ballast consists of a current source, AC/DC converter and a full-bridge inverter. The electronic supply provides to the lamp a different form of current excitation (square waves with variable short drops). Dimming control and the characteristics of low frequency operated high intensity discharge lamps are described. The lamp is represented in a simulation by its conductance model and coupled to its electronic power supply. Experimental results are shown and compared with the simulation. A dimming range from 100% to about 60% has been achieved.

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