Auto LED brightness from Fan Header

[Wastedfun]

Hello
I am looking to control an array of LED lights inside my case that will use the fan power settings as a reference. Preferably the CPU setting, but will be okay with the system fan headers.

Basically I want my case to have one set of LEDS that are always lit up, then a second set that will be dim when the computer is idle. When the PC ramps up fans while under load it will increase the brightness of the second set of LED's.

Any suggestions on how to make this happen? From what I can read the variable voltage of the fan header may not supply the correct type of power needed for LED strips, at least to dim then. (something about amps not being correct?)

Thank you
-Wasted

 

[jimmysmitty]

Headers runoff the 12V rail and at most provide 1A, in most cases. If it is not enough amps for the strip then there is not much you can do that I could think of short of getting a sound based one like we had in the old CCFL days and place it next to a PWM controlled fan.

 

[ingtar33]

Hello
I am looking to control an array of LED lights inside my case that will use the fan power settings as a reference. Preferably the CPU setting, but will be okay with the system fan headers.

Basically I want my case to have one set of LEDS that are always lit up, then a second set that will be dim when the computer is idle. When the PC ramps up fans while under load it will increase the brightness of the second set of LED's.

Any suggestions on how to make this happen? From what I can read the variable voltage of the fan header may not supply the correct type of power needed for LED strips, at least to dim then. (something about amps not being correct?)

Thank you
-Wasted

correct, fan headers won't work because they don't send power in the right way.

the only way i can assume something like this would work is if you used something like the corsair commander. that might allow you to do just this with the lights. however i've never used it so i don't know if its possible.

 

[jsmithepa]

U kids getting ready for Christmas or s'thing?

provide 1A, in most cases.

Today's LED are very efficient, allow 10mA per bulb and that's plenty bright.

The fixed brightness LED is easy. Just hook it up to a 4-pin power connector, 5 or 12v, whatever the "string" takes.

The variables, oy, can't do it through the fan headers as explained, but maybe those variable voltage fan controllers. Do you know your voltages and amps, own a soldering iron and know how to use?

ps: Actually PWM *may* work for LED, as long as the voltage remain in range, but I don't know whether our eyes can tell the flicker of the PWM frequency used. Try it and TELL US! (as long as you get the voltage issue resolved).

 

[ingtar33]

I think PWM (Pulse width modulaiton) works via "power osolation"... i am almost 100% sure you wouldn't be able to plug lights into them; as it works via rapid modulation of the power signal.

it would be more likely to work with a 3 pin header though. that said i doubt you could match a 3 pin fan header to a light in the right voltage/watt range