Car LED Halos for Case Fans?

Nobu

Supreme [H]ardness
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Jun 7, 2007
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So, I'm kinda disappointed in the lack of good static-pressure fans with LEDs, and I'm not convinced an LED strip placed around/behind my fans would look as good as integrated LEDs, nor would I like to drill holes in my fans. o_O

So I was browsing around, saw these, and thought, "hmm, I wonder if I could slip these in behind my fans/if it would look good." Being the cautious consumer I am, I thought I'd ask what you all thought about this before I decided to go for it. ;)

There are other colors, but they're a good bit more expensive--at that point, might as well get a flexable strip and wrap it around the fan. One little roadblock to this idea is I don't have a soldering iron or crimping tools, so I'd have to get one/both before I could even try, but I thought it was an interesting idea, at least.
 

Nobu

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Well that's why I said behind the fan (which would be in front of a radiator, in my case), but anyway you could always lower the brightness with a resistor or by using a lower supply voltage than the LEDs are rated for (12V). That said, you still think it'd look bad?
 

Ocellaris

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You can't just lower the voltage and expect the LEDs to dim, they may just flicker or not work.
 

Nobu

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One reviewer said they were able to dim them using an LED dimmer, but didn't specify whether it did so using voltage/current regulation or PWM. Either way, if I have to, PWM controllers aren't exactly expensive or difficult to find.

Thanks for the replies, btw. Wanted to say thanks last time but forgot before I hit submit.
 

KazeoHin

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I'm pretty sure LEDs require PWM to dim. LEDs are either 'on' or 'off', they have varying degrees of output when transitioning between the two states, but there isn't a way to hold them at a constant '50%' brightness from what I understand. The PWM would do the trick.
 

Nobu

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You can use a trimmer potentiometer, but yeah, it'd be very difficult to use just a resistor to reduce the brightness without (or even with) knowing the characteristics of the specific LEDs you're working with, since the current drops so rapidly once you approach the threshold voltage. One way would be to set the pot to the brightness level you want your LEDs at, then measure the voltage drop across it and use that to figure out what kind of resistor you'd need...but at that point you might as well just leave the pot in the circuit--it's not that big, after all.
 
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