Originally Posted by The viking
When it comes to the leds on the front of the HAF, how many Volts do they need, or use?
I'm going to change them to Green ones, and i need to know i have to buy resistors or whatever its called.
Thx in advance!
I measured the voltage across those reds in the front fan
and they are 2V. According to another LED replacement thread talking about that very fan HERE
, the resistors are in the fan but are surface mount so forget about taking them out. If you can find 2V bright greens, go for it. Google "LED Calculator" for some online tools that can help you for calculating the resistors needed for specific LED setups - Forward Voltage is the key voltage to look for with LED specifications.
Take a look at this resource for sizing an LED circuit. It will give you the current limiting resistor size you would need based on the inputs. So you would use 12V for your source voltage, "diode forward voltage" is the LED Forward Voltage rating, diode current rating (many LEDs are 20mA but check the spec) and then the number of LEDs (diodes). I've seen mention of having a resistor in there as a current limiter (even 4x3V LEDs on 12V results with a 1 Ohm resistor in the guide) - I'm guessing that is so the LEDs which are in fact diodes do not get cooked by having too much current go through them.Edited by HAFenvy - 9/13/09 at 8:17pm