im looking more for a speed controler what will regulate the speed of the
fan by the temp prope.
By what temp probe?
If you mean by the motherboard temp probe, that MUST be a
feature of the motherboard, unless you want to build a
custom circuit then solder wires to the CPU socket pins,
make a SMBUS interface.
A better question is WHY you feel you need this control?
It is definitely NOT necessary to keep the CPU at a fixed
temp. If the argument is to redue noise, then what's going
to happen if the system has faster fan? It's louder.
Typically a fixed single-speed fan is a good choice unless
one is using a marginal heatsink that needed overly high RPM
to deal with CPU load in the first place. Otherwise, using
a heatsink-fan combination that has acceptable (low) noise
levels at full load (by the user's chosen fan speed limitor)
will simply keep CPU a few, maybe 2-6, degrees cooler at
idle. The key is using a large, thick fan with low RPM,
and heatsink design that makes the most of the fan diameter.
A direct temp to fan speed control is a nice idea on paper,
but in practice the added complexity doens't necessarily
address any real problem, more a situation of doing it
because it's possible rather than useful. Not just a
theory, I've build quiet systems using fixed-speed fans for
years, including highly o'c CPUs.
Even so, if you want that kind of control you could just buy
a fan that already implements that feature, or use something
like an LM317 adjustable linear regulator with the thermal
sensor as part of the control resistors (see LM317 circuits
on the web), placing the sensor wherever you want it, like
in the heatsink fins or a hole bored into base of 'sink.
Typically that won't be very responsive though, the CPU core
temp will vary more than the heatsink metal.
