破解AC-LED的迷思

c8051f300

Thank you for sharing. Good material

fsshlin

我也來跟各位學習LED這個新領域!

innochipper

AC-LED技術還需要提高，可能有其發揮空間

aaddmich

AC LED 需要克服的部份
1.電流隨著電壓變化
2.LED的使用效率變差(AC LED發光的時機不是轉換效率最高)
3.LED成本增加(LED晶片上需要更多區域做LED間的接線)
目前我覺得這三個部份是無解。
作法上就是對LED做加工去省AC-DC轉換電路
AC LED可能有市場的情況是在LED的價格~AC-DC電路的價格
以目前的成本結構來說LED價格>>AC-DC
現在看起來是花大錢省小錢。
電光所做AC LED不知道有沒有找能資所的人問問......

D8807305

Thanks for your information.
I like this one

kevinchime2

AC LED might be good in low wattage application but not as good as high wattage application. The unit price for AC LED is about USD 6.0/ 5W which is able to generate the Lumen at 50X5 = 250lm, but this figure is just for the pure LED only not take the diffuser, Lens and the reflector optical loss into account. Not to metion the thermal may drive down its lumen output. One more concern is the IP. I'm sure Epistar's AC LED is not allowed for the Japan market maybe other countries as well.

Take the DC LED as reference, the price is about USD 1.2/ W but the lumen efficiency is 100 lm/w which is about twice than AC LED. The DC LED application just has the problem in low wattage application. Like the night light, however take the safety into concern to buy the lighting fixture made by DC LED is safer. There are a lot of the pros and cons between the AC/DC LED, technically DC LED has better chance.

chris77jw

回復 25# jiming


    謝謝大大

goodspeed.yang

感謝分享,
AC-LED的市場的確直得多關注

moda710915

原PO是高手，相當認同，LED BACKLIGHT須調光、定功率等技術，並非簡簡單單加個限流電阻就好

lcchi

工研院的AC LED應是將LED排成橋是整流器的架構,中間一串always發光, 但其餘則僅在一半時間導通發光,不是嗎??

show123467

我認為發展HV LED 才是正道
配上其他元件 亦可達到高PF 的效果
且成本低

glennking

AC-LED大約超過4W就會發現有熱所造成的閃爍的問題!!
除非找出非linear的控制方式~
不然熱消耗所造成LED的熱累積~
長期下來不是LED燒毀就是Driver電路毀損~
AC-LED驅動方式目前聽到不外乎就

1.串聯電阻驅動
2.CRD驅動
3.Linear分段驅動電路 (EX. AIC6600)
不過以上的方法好像都無法避免效率差~熱累積的問題!!
如果各位大大有其他的驅動方式~看有無機會討論看看~
若能解決熱的問題~AC-LED才有希望大功率方向前進...........