Abstract: The invention consists of developing an environmentally friendly new energy converter using light weight material. The energy converter shall be fully submersed in running undercurrents waters and have high overall efficiency ratio. The energy converter consists of, among other things, eliminating the in-line electric generator and substitute it with peripheral electro-magnetic coupling device, attached to the runner tip from inside and surrounding the energy converter housing from outside. The energy converter electric brushless circuits and winding must be totally sealed from water, using new sealing techniques and shall be also electrically isolated as well. The energy converter allows extracting energies from undercurrents with large frequency and voltage ranges.

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.

Abstract: A nonimaging lens consists of a solid body of light-propagating material defining a first light-refracting surface, a second light-reflecting surface and a third light-refracting surface. To redirect the generally parallel light rays of a directional light beam, the first light-refracting surface diverges the light rays of this beam, the second surface reflects the divergent light rays, and the third surface refracts these reflected light rays. To concentrate dispersed light rays into a generally directional light beam, the third surface first refracts the light rays, the second light-reflecting surface converges these refracted light rays, and the first surface refracts the convergent light rays toward the generally directional light beam. In accordance with one embodiment, the first light-refracting surface and the second light-reflecting surface are conical, open out in opposite directions, and respectively define skewed refraction and reflection axes.