Well here is how you can implement the LED indicator being talked about
here:
(ascii art follows)
+V (Red Wire) o--------+-------------------------------o
| ..
+--/\/\/\/----->|-----+
>From Motherboard Resistor LED | TO CPU FAN
R |
|
GND (Black Wire) o---------------------------+---------o
Now the value of the resistor can be derived as:
R = (V - 1.5) / (25 * 10^(-3))
V is the voltage being supplied to the CPU fan, wither 12v or 8v
For most LEDs 1.5v is the voltage drop across the LED when it is lit-up. And
the current throught the LED is 25*10^(-3) A = 25mA for maximum birghtness.
For V=12v, the value of R = 420 ohms
For V=5v, the value of R = 140 ohms
Any nearby value of the resistor may be used. Be careful about the polarity
of the LED as it won't work if connected the wrong way. In the diagram the
end with the | is the -ve terminal (usually marked by a shorter lead).
HTH
Cheerio!
,_,
(O,O) Vipul Mathur <[EMAIL PROTECTED]>
( ) http://www.crosswinds.net/~vipul/
+---"-"------------------------------------------------------------------+
| 'The most exciting phrase to hear in science, the one that heralds new |
| discoveries, is not "Eureka!" but "Hmm. That's funny..."'-Isaac Asimov |
+------------------------------------------------------------------------+
A good programmer makes all the right mistakes
Durga Prasad Allada <[EMAIL PROTECTED]> wrote:
> Soldering an LED is a goiod idea and it will not drain much current nor
> effect the Fan performance.BUt must make sure the power to Fan is driven
> by AC or DC..and if DC is it at 12 V or 5 Vand select a
> right LED matching this power input..
> - durga
>
> Raju Mathur wrote:
> > Solder an LED there yourself :-)
> >
> > Warning: I don't know if this will affect the fan speed.
> >
> > >>>>> "Ajit" == Ajit Ranade <[EMAIL PROTECTED]> writes:
> >
> > Ajit> raju-
> >
> > Ajit> i did check the bios, and it has a setting for turning off
> > Ajit> the cpu fan during "suspend" state. but otherwise there was
> > Ajit> nothing about sensing whether cpu fan is on or
> > Ajit> not. shouldn't oem's put a led or something, or will that
> > Ajit> consume too much power, relative to its utility.
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