rim 7 a contacts inner surface 18 of housing 2 adjacent mounting surface 4 and base 7 b contacts the upper surface of heat sink plate 5 in this manner the present invention prevents direct thermal conduction between array 10 and tcpcb 13 and housing 2 or heat sink plate 5 a passage 20 in insulation barrier 7 tightly conforms to an outline of each tem 6 while allowing the cold surface of each tem 6 to thermally contact tcpcb 13 and the hot surface of each tem 6 to thermally contact heat sink plate 5 holes channels or passages all not shown within insulation barrier 7 allow sealing passage for electrical connectors 17 from tem s 6 to electronic control module 8 insulation barrier 7 forms a mechanically secure and gas tight seal between inner surface 18 and heat sink plate 5 and prevents convection and conduction heating of tcpcb 13 by either heat sink plate 5 or housing 2 insulation barrier 7 is formed from any desirably thermally resistive material including ceramics or a plastics and may additionally include internal air spaces to improve thermal efficiency a cavity 19 in insulation barrier 7 closely houses electronic control module 8 and prevents thermal transfer between electronic control module 8 and heat sink plate 5 a thermal sensor 9 contacts a rear surface of metal layer 11 and senses a temperature directly related to an operational temperature of light emitting array 10 cavity 19.