LEDs have been developed by Seoul Semiconductor that can operate on AC power without the need for a DC converter. For each half-cycle, part of the LED emits light and part is dark, and this is reversed during the next half-cycle. The efficacy of this type of HP-LED is typically 40 lm/W. A large number of LED elements in series may be able to operate directly from line voltage. In 2009, Seoul Semiconductor released a high DC voltage LED, named as 'Acrich MJT', capable of being driven from AC power with a simple controlling circuit. The low-power dissipation of these LEDs affords them more flexibility than the original AC LED design. COUNT 5
QSN1 What company has developed LEDs that can operate on AC power? ANS1 Seoul Semiconductor QSN2 What is the efficacy of an AC powered HP-LED? ANS2 40 lm/W QSN3 When did Seoul Semiconductor release the first high DC voltage LED? ANS3 2009 QSN4 What is so good about ac powered HP-LEDs? ANS4 more flexibility QSN5 What did Seoul Semiconductor name their ac powered HP-LED? ANS5 Acrich MJT