||The idea to achieve a high efficacy retrofit for incandescent lamps by combining a halogen capsule, an IR reflective coating and a low voltage transformer has existed for many decades. During the 1970s GE filed a patent on the concept, and the author of this website developed the first working prototype which was widely published at the end of 1999. Despite these technical achievements, such a product would have been prohibitively expensive to put into production. That final hurdle took a decade to overcome, and Philips launched the concept at the April 2008 Frankfurt Fair.
The heart of the Philips lamp design is a low voltage single ended quartz halogen capsule having an infra-red reflective coating to raise its efficacy. In the region of the lamp cap and extending partially into the bulb area is an electronic transformer which steps the 230V mains voltage down to just under 12V. The transformer is potted in a thermally conductive rubber compound to keep it cool, and incident heat radiation from the capsule is reflected away from the sensitive electronics thanks to an inner glass shield bearing a heat-reflective aluminium coating.
The result is a lamp drawing just 30 Watts but whose luminous flux was originally claimed to match a 230V 60W incandescent lamp (although the manufacturer has since revised that claim to match only a theoretical 52W lamp). Lifetime is extended to 3000 hours. It offers many of the traditional GLS advantages of being compact, dimmable, instant light, and delivers a warm 2900K white light right on the blackbody locus. The cost however remains relatively high. As of end 2010 most retailers who initially stocked this lamp have now abandoned the concept due to weak sales.