Well, I decided a short while ago to spray my CM 690 black and swap out the blue fans for red, one fan however would be hard to replace, a 220mm (Akasa one bit-tech hates, I know it shifts no air but its for look ), I headed down to maplins to get 5 red LEDs to switch the fan LEDs for then when I got there I realised how stupid I'd been, the fan, like all fans, is 12V, but the problem is, I had NO idea what the output voltage for the led channels would be, if it was 12V (somehow) and I stuck a 2V LED on.... Can anyone give me advice, help or even better a definitive output on the likely output of an LED channel on a fan, or a solution to my connundrum
hey moyo. if you're using a 12v supply to your fan/led's, you'll need to put a current limiting resistor in series with the led (red led is 1.8V with a current of 20mA). for a 12v supply it would be roughly 510 ohms, but you could probably get away with 470 ohms. maplin code off the top of my head is M470R? but you want to run 4 leds? so use http://www.theledlight.com/ledcircuits.html .Its good to learn from...very simple.
oky doky. have a look at this. http://www.kpsec.freeuk.com/components/led.htm#series It explains it perfectly. One resistor in series. How many leds on a fan? 3? Based on that, and them being standard red leds (i'm guessing?), you can assume that each led is 2V, and the current needed is 20mA (not 15 like they say, unless you want slightly dim led's!!). So with a 12V supply from an ATX psu, you will need a 300 ohm resistor. Use a 330 ohm, as that is a standard value. Maplin code for this is...M330R i think. Let me know how it goes mate. Cheers
please excuse me, i'm an idiot. didn't read post again!!. its 5 leds you need, so resistor will be 100R for a nice chain of 5 leds. I can't remember what the effects of the chain being too long are....dim led's at one end or something like that. Led's and resistors are cheap, so have a ball.. experiment. I been out of the game for ages, so i'm a bit rusty.
