||This is the first LED retrofit which can claim lumen equivalency to a 60W high voltage incandescent lamp, as required in European Regulation 244/2009. That sets a tough target of 806 lumens - basically 15% higher than the lighting design lumens of a 60W coiled-coil GLS lamp, to account for the expected 30% lumen depreciation of this LED during life.
Considering the fact that the efficacy of a typical high power LED retrofit lamp during 2010 was around 50lm/W, meeting the 806lm target by conventional means would require a power consumption of about 16W. Such high wattage cannot be dissipated in the relatively small volume of the A60/A19 bulb envelope. A particularly elegant approach has been taken in this lamp to raise its operating efficacy such that it can meet the 806lm target for a power consumption of only 12½W.
This is faciliated partly by under-driving a large quantity of LEDs so that they operate cooler and more efficiently, and by employing blue LEDs to pump a remote phosphor contained within the plastic housing of the bulb envelope. Keeping the phosphor cool plus under-running the LEDs achieves an efficacy boost of about 20% above conventional white LEDs.
The plastic appears yellow because of the presence of the phosphor powders, but lights up white when in operation thanks to a mixture of the phosphor radiation and some transmitted blue light from the LEDs inside. The novel design of the fluorescent bulb surface also results in a much greater proportion of light towards the lamp cap, to better mimic the omnidirectional light distribution of incandescent lamps. A high efficiency electronic driver is also employed, which has broad compatibility with many existing dimmer switches.