Abstract: The light-emitting-diode lamp comprises a set of light-emitting diodes, a rectifier and power converter circuit, and a power factor controller. The rectifier and power converter circuit converts ac or dc voltage and current from a power source to dc voltage and current supplied to the set of light emitting diodes. The rectifier and power converter circuit includes an electronic switch through which it is supplied with ac or dc voltage and current from the power source, and an inductor device including windings adapted to charge a capacitor with a voltage signal representative of the amplitude of the ac or dc voltage from the power source. The power factor controller is responsive to the voltage signal across the capacitor for controlling the electronic switch of the rectifier and power converter circuit in view of supplying dc voltage and current to the set of light emitting diodes while maintaining the power factor of the light-emitting-diode lamp equal to or close to unity.

Abstract: A traffic signal light comprises an array of light-emitting diodes for producing respective light rays, and an array of lenses for propagating light rays from the light-emitting diodes toward a plurality of predetermined, distinct spatial points. The lenses are each associated with a corresponding one of the light-emitting diodes, and each lens comprises a solid body of light-propagating material defining a light-refracting surface through which the light rays from the corresponding light-emitting diode propagate. The light-refracting surface is divided into distinct light-refracting surface sections each associated to a corresponding one of the spatial points. The light-refracting surface sections have different configurations in view of deviating the light rays propagating therethrough toward the associated spatial points, respectively. Therefore, at each spatial point add the light rays deviated by the associated light-refracting surface sections of the different lenses.