Light Emitting Diodes (LED) are semiconductor devices which, combined to phosphors, emit white light with high efficacy surpassing conventional light sources. Elementary LED is not suffisant to light a piece. It need to be associated with others and combined to a power supply to constitute a complete luminaire. Actually, “wall-plug” efficacy drops a lot due to factors such as optical attenuation, electrical connections losses, thermal impact, ... To develop optimal electrical supply, a study was conducted to increase knowledge on interactions between LEDs technologies, their topology, current level supply and luminous efficacy..., A more precise electrical model than classical used for light was developed. Simulation results on original LED matrix with its new modeling are shown. An experimental board was developed to validate our approach with real electrical characterizations.