Ok, so I finnaly got my hands on all the parts I need, but there's a problem... It's not working

When I tap the FET the fan starts spinning and if I don't do that nothing happens...

I'm guessing that the FET is damaged, but am not sure...

What do you think?

I'm currently "worried" so to say about the divider.

Will it allow me to change the voltage 2x a second?

For the divider I'm not sure if 1k resistor and a 18uF capacitor will suit my needs...

For the fan control I will be regulating 12V, the voltages which will be "available" for the fans are: 7V, 8V, 9V, 10V, 11V, 12V and will be changed as the temperature of the CPU Changes. I'm expecting the voltage change to occur no higher than 2x a second.

Thank you!

I think I found something that will fit my needs: http://eu.mouser.com/ProductDetail/Fairchild-Semiconductor/FDP7030BL/?qs=sGAEpiMZZMvECErq9cesgOhjwE8m5zTM4sOaJqrLpIU%3d


Now for the (hopefully) last question: How do I connect everything?

Something like this?

                                                                      12V
                                                                       |
                                                                       |Source pin
                                                                       |
|Digital Pin 9|----|Resistor|----|Capacitor|--Gate--|MOSFET|
                                                                       |
                                                                       |Drain pin
                                                                       |
                                                                      Load(Fan)
                                                                       |
                                                                       |
                                                                       |
                                                                     GND

@Grumpy_Mike

So: N-Channel FET, TO-220, 5V Turn on voltage, low on resistance, low resistance drain-to-source, and of course, drain source voltage high enough and same for current ?

Can anyone tell me what I must pay attention to when choosing a FET for using it to regulate voltage with Arduino?

I found something a bit cheaper than the previous I linked and am not sure if it will work...

http://eu.mouser.com/ProductDetail/Fairchild-Semiconductor/FDP6030BL/?qs=sGAEpiMZZMutXGli8Ay4kBEMMAKgSkd8MdwkNnQ%2fGU8%3d

Alright!

Now, if only I could find that in Eagle

@Grumpy_Mike

Thanks!

I hope I'm not too annoying with all these questions , maybe something like this? http://www.nteinc.com/specs/2900to2999/pdf/nte2987.pdf

Could you also tell me what exactly am I look for? N-Channel MOSFETS?

So I use Frequency dependent potential divider with low pass filter connected to a FET, and the divider is hooked up to Arduino PWM output pin? And if so, which FET should I use?

Can you give me more info on using FET's with Arduino? Schematic(s), Maybe even some example code 

I'll be using the same PSU for: Pumps (Water Cooling), Micro Controllers, Fans

Thanks for the replies guys

Any idea on how I would get more than 12V with a PC PSU?

Hello again

I will be making an Arduino fan controller which will regulate the voltage on the fan with the help of the LM317 Voltage Regulator, now I have made a schematic and I have a question:

The input voltage will be 12V from a PC PSU, will the LM317 be able to give 12V output?