What is said to be the world's first LED that runs directly from ac power comes from Seoul Semiconductor Co. Ltd. in Korea.
The company's Acriche LEDs provide warm-white light suitable for indoor lighting. A luminous efficiency of 42 lumens/W is 20% more efficient than conventional warm-white dc LEDs. Actual system efficiency — corrected for luminous efficacy, ballast efficiency, and luminaire efficiency — is 39.9 lumens/W. By comparison, actual system efficiency for incandescent lamps is 7.5 lumens/W, and 30.6 lumens/W for compact fluorescents.
The so-called color-rendering index (CRI) is a measure of a light source's ability to produce vibrant colors on objects receiving the light. A CRI rating of 100 is equivalent to daylight, while a CRI near zero suggests colors appear unnatural under that particular light source. Acriche warm-white LEDs have a CRI of 90. The LEDs last 35,000 hr compared to 1,000, 3,500, and 8,000 hr for incandescent, halogen, and fluorescent lamps, respectively.
Seoul Semiconductor Co. Ltd.,