| 摘要 |
A luminaire has a light source (1) in the form of a quartz crucible (2), having a plasma void (3). A power supply has a magnetron (5) for providing microwaves for generating a plasma in the void. An air wave guide (6) is connected below the magnetron and a connector (7) is connected below the wave guide. The plasma crucible is fitted to the bottom of the connector and is enclosed by a Faraday cage (8). Arranged with the crucible at its focal point is a reflector (11). It has a central (aperture 12), through which the connector (7) extends. A lower, hemispherical shell (15) of a casing (16) for the power supply supports the reflector at a similar aperture (17), with the interposition of one or more focus adjusting spacers (18). The reflector is fixed to the shell with screws (19). The lower shell curves up and away from the reflector hemispherically, enclosing the power supply within its bowl. A cooling fan (43) is mounted at the top of the casing and supported by a (duct 46), extending up from the magnetron. The duct leads air flow to cooling fins of the magnetron. Thence, it flows down to and through the annular gap (47) formed by the apertures (12, 17) in the reflector and the lower shell with the connector (7). Thus the connector is cooled and the crucible with its Faraday cage, which together run hotter, is also cooled. The cooling air exits the luminaire via gaps at the bottom of the reflector between the reflector and a transparent cover (48). |
