Light-emitting device circuit and method of operating thereof

摘要

The light-emitting device disclosed herein comprises a step down circuit and a current limit device, wherein the step down circuit prevents the current signal provided to the light-emitting device larger than the rating current value of the light-emitting device. Moreover, the current limit device only limits current signal while the power supply surges. The two stages protect circuit turn less power to heat.

主权项

1. A light-emitting device circuit, comprising:
a step down circuit configured to receive an AC signal with a profile having a highest portion, a lower portion with a highest value, and a flat portion lower than the highest portion and the lower portion, and provide an alternating current after removing the highest portion while substantially keeping the lower portion unchanged; a rectifier electrically connected to the step down circuit and configured to rectify the alternating current; a light-emitting device electrically connected to the rectifier and having a rating current value and an ideal operating current peak value; and a current limit device electrically connected to the light-emitting device and configured to limit a current for passing through the light-emitting device when the current is greater than a current limit value, wherein the current limit value is larger than the ideal operating current peak value and less than the rating current value, and wherein the highest value is greater than the rating current value.