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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The objective of this work is to study the influence of a pulsed power supply on the energy efficiency of high-intensity discharge lamps in comparison with a pseudo-continuous ballast. The results presented in this paper concern the dynamic behaviour of discharges in mercury vapour doped with thallium iodide. The acquisition of the arc current, arc voltage and spectral radiation enables us to investigate the influence of the pulsed power supply on the electrical characteristics of the lamp such as the behaviour of the lamp conductance and spectral radiance. The analysis of the 577 nm mercury line’s response to the current pulse excitation allowed us to identify several phases. Good agreement has been found between simulation and experimental results.

Nowadays, LED lights take an important place in our daily lives and they have known a great growth in indoor as well as in outdoor lighting applications. LED (Light Emitting Diode) light sources including their own drivers have excluded many systems fitted with both inefficient light sources. In this paper we present, a LED driver handling a DC input power supply and piloting a series of powered LEDs Some topologies of LED driver supplying a constant voltage or a constant current toward a LED load and their operations are detailed and presented. In this regard, two types of DC-DC converter in occurrence buck and boost converter are analyzed, designed, and simulated. Furthermore, a design of laboratory prototype of constant-current LED drivers based on DC-DC buck converter totally dimed is achieved, and tested. Calculated and experimental results are in good correspondence with very small deviation of LED current in both cases for different levels of dimming.