An indoor lighting arrangement employing a combination of high pressure sodium (HPS) light sources, which produce a yellowish light, and mercury vapor or metal halide light sources, which produce a whiter light. Where the distance between the floor and the plane containing the light sources is at least fifteen feet, the HPS and whiter light sources are mounted in a checkerboard pattern so that the yellow and white illumination which they produce is completely mixed at normal eye level. When lower ceiling heights are involved, lighting fixtures are used which each contain both an HPS lamp and a whiter light lamp.
An advanced solar simulator illuminates the surface a very large solar array, such as one twenty feet by twenty feet in area, from a distance of about twenty-six feet with an essentially uniform intensity field of pulsed light of an intensity of one AMO, enabling the solar array to be efficiently tested with light that emulates the sun. Light modifiers sculpt a portion of the light generated by an electrically powered high power Xenon lamp and together with direct light from the lamp provide uniform intensity illumination throughout the solar array, compensating for the "square law" and "cosine law" reduction in direct light intensity, particularly at the corner locations of the array. At any location within the array the sum of the direct light and reflected light is essentially constant.
A flat reflector lamp for fluorescent bulbs is described. The lamp has a self-supporting reflector with an enclosed hollow portion for mounting an electronic ballast. Electrical sockets on a pair of lamp end plates function as mounts for fluorescent lamps. A circuit board mounted on guide strips within the enclosed hollow portion of the lamp has spring contacts in electrical contact with at least one of the electrical sockets.
An apparatus for illumination generating artificial light which resembles natural light as much as possible comprises a light source radiating substantially in the blue-green region, such as a fluorescent lamp (16a,b,c,d) and at least one incandescent lamp (18). Prior to exiting from a housing (12) of the illumination equipment the light of the light source radiating blue-green is reflected at least once from a white wall (14). This applies also, in part at least, to the light of the incandescent lamp (18).
The illumination system includes a plurality of illumination structures (10), the illumination structures being arranged around the periphery of the playing field. Each illumination structure (10) includes a mounting pole (12) and a plurality of luminaires which are individually mounted by mounting arms from the pole. The luminaires are cut-off forward-throw luminaires. The luminaires are arranged relative to each other such that each luminaire, respectively, does not block light originating from any of the other luminaires.
