T j = Ta + ( R th b-a x P total ) + ( R th j-sp x PLED )Tj = LED junction temperature
Ta = Ambient temperature
R th b-a = Heat sink thermal resistance
PLED = Single LED power consumption
= (Operating current) x (Typical Vf @ Operating current)
P total = Total power consumption = (# LEDs) x PLED
R th j-sp = LED package thermal resistance
我的疑问是 LED 系统除了大部分热量由LED产生,但是还有driver components, AC/DC module 也产生热量, 这些热量最终也是通过LED 外壳(铸铝散热器)到环境.
所以我的理解是以上公司中的P total=(# LEDs) x PLED +power of other components.
期待高人指点..
Cree_thermal design for heat sink of LED.JPG (139.44 KB)
