Hi, is it safe to connect multiple power LEDs to the same PWR LED pins in the motherboard? I'd like to add 5 or 6 additional LEDs for cool looks, but afraid the additional current draw might not be something those pins are expecting? Don't wanna damage the motherboard in the process if you know what I mean. The LEDs would be connecting in parallel of course.
Thanks!
On most older boards the Power LED is right off the +5v line thru a resistor. You cannot parallel very many as the resistor limits the current to about 10-15mA iirc
You could use a Molex connector and it's +5v. Figure how many LED's and put a resistor to drop ~3v across to get ~2v and still provide the current needed depending on the exact type of LEDs.
example: 5 x 20mA LEDs = 100mA, drop 3v @ 100mA = 30 so a 33ohm. If say 5 x 10mA LEDS then 60 or a 68ohm, and the resistor should be a 1/2watt type for safety.....
Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun
That makes sense Horun, thanks for the explanation. I'll take the power from the molex then. I was hoping I could extend the idea to the HDD activity LED as well.. but I think that will be a different story.
You can sometimes use the spare turbo led header as a power led if it is a non turbo mobo that just gives you the header so you can make your light go.
But, if you want a lot of LEDs, what about using 5v fan to molex adapters and a inline fan slow down resistor (idk if that resistor will be correct, but testing it only risks a LED, so…)
Or you could make something. On a bread board.
Basically the LED needs a resistor the value of that resistor varies by voltage, LED and desired light output.
It may be possible to use one of those massive potentiometer based fan controllers with a thousand ports on them with fan slow down resistors on each port.
If using the 5 volts, be sure to use a separate resistor per LED. A shared resistor might yield very uneven brightness in the LEDs due to differences in forward voltage drop and current.
Please use the "quote" option if asking questions to what I write - it will really up the chances of me noticing 😀
H3nrik V! wrote on 2023-01-20, 05:08:If using the 5 volts, be sure to use a separate resistor per LED. A shared resistor might yield very uneven brightness in the LEDs due to differences in forward voltage drop and current.
If expanding on my reply. Yes, I meant to imply seperate. 😀
Btw, I highly suggest if you ever get the chance to play with a LED on a variable voltage/ current psu that you do so.
There is a point where the LED is lit up dimly but current is almost nothing. And passing that the current starts off on a exponential curve it seems. This is why they need that resistor.
