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LEDs on 3.3v line

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bchur83

Member
Joined
Jan 26, 2003
Location
Land of 10,000 Lakes
Can you hook an LED rated for 3.1v - 3.8v, directly to the 3.3v line, or do you still need a resistor in there? I have been thinking of getting some LEDs to mod a case, and was wondering if this will work, or should I just run them off of the 12v line with resistors?

Also, what rating of resistor would I need for running them off of the 12v line? Does it vary according to the rating of the LED?
 
it does vary, more or less by color.

whites tend to pull 3-3.5volts, ambers ussually 2volts, yellows and greens around 2.5. blues are the same as white.

you shouldnt have any problem with the 3.3volt line. chances are the LED doesnt run EXACTLY 3.3volts, and it would only really be feasable for blue or white, but if its those colors, then the distance from the proper voltage shouldnt be enough to cause a problem, maybe shorten its life, but still get a few solid years out of it.

in a 12volt line youd need resistors, and you gotta know the voltage of the LEDs you plan to run in the series.
 
Well I am looking at Blue LEDs, and they are rated at 3.1v - 3.8v, 3.5 typical. So do you think they would work just fine without a resistor?
 
you can get led's at different voltages, check out ebay, i got a crap load of 5v's for my mouse, even though i learned that the power is actualy 3.3v at the led, oops!
 
they should work fine. 1 to a series of course. but yeah, assume the typical. might not be... but typicly safe to assume.
 
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