LED俾1cell鋰電用要幾大e電阻才可以最光又唔燒ga?

原帖由 eddie1987 於 2008-10-23 00:09 發表

                               
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我唔加電阻就幾個鐘就一粒啦,好煩呀,加左d100ohm又唔光wo,只有3.1v咁,唔知幾大先係最fit ga?

try this website:
http://led.linear1.org/1led.wiz

Source voltage: 4.2
diode forward voltage: 3.0
diode forward current (mA): 20

answer: 68ohms