Apparatus and method for operating a portable xenon arc searchlight

An apparatus for producing an adjustable high intensity, narrow, substantially collimated which includes a user adjustable zoom beam of light comprising:

• an xenon or metal halide arc lamp which is characterized by a short longitudinal arc;
• a single reflector surrounding said lamp, said single reflector having a longitudinal optical axis and a focal range on said longitudinal optical axis from which light is reflected within a predetermined range of collimation of said beam of light;
• a threaded coupling between said lamp and single reflector;
• wherein said single reflector is longitudinally displaceable relative to said lamp while in use so that said single reflector is longitudinally displaced by means of rotation about said threaded coupling while in use and while maintaining said arc lamp on said longitudinal optical axis within said focal range;
• and
• a lamp holder having a shoulder in sliding juxtaposition with said reflector to maintain said reflector on said longitudinal optical axis as said reflector is longitudinal displaced by means of rotation about said threaded coupling.

A searchlight for producing a narrow, substantially collimated beam which includes a user adjustable zoom comprising:

• a lamp which is characterized by a short longitudinal arc;
• a lamp circuit coupled to said lamp for powering and controlling illumination produced by said lamp;
• a single reflector disposed about said lamp to reflect light generated by said lamp in a forward direction, and which single reflector is characterized by a longitudinal axis extending rearwardly and forwardly;
• a reflector positioner comprising a threaded coupling between said reflector and a housing of said searchlight so that said single reflector is selectively displaced with respect to said housing by means of rotation about said threaded coupling while in use and while said lamp remains fixed relative to said housing;
• said lamp having an anode and a cathode, said anode being positioned rearwardly along said longitudinal axis relative to said cathode, whereby the field of illumination of said beam of light is rendered more uniform;
• and
• a fluted heat sink fixed on said housing to conductively dissipate lamp heat from said anode.