The Q6008LH1LED and Q6012LH1LED series of AlternistorTriac, and the Q6008LTH1LED and Q6012LTH1LED series of QUADRAC thyristor power control devices are designed for use as the switch in a dimmer circuit to adjust the light output of light emitting diode (LED) bulbs and strings. They allow designers of AC line-based dimmers for LED lighting to accommodate a wide range of operating parameters without sacrificing reliability, and without degrading the performance of the dimmer. As a result, a single control device can be used for LED-based dimmers or for combination dimmers designed for incandescent, compact fluorescent lamp (CFL), and LED loads.