Hi,I am going to add a temp-controlled fan assembly to my home theatre cabinet. From my googling I believe I understand how I would have to use a MOSFET for this, but all the examples have an additional 12V power supply. How would I go about using a single power supply to power both the arduino and two 12V fans? Is it as simple as taking a 12V power supply and simply attaching it to both (since it appears the arduino has a regulator capable of handling this voltage)? If so, would this end up generating an excessive amount of heat/waste energy?Thanks!
If you want a packaged and "done" solution, I have used this little board to run a motor. It wouldn't care it's a DC fan and you can either turn it full on or PWM. You can even control both fans independently since this board has two L298 H-Bridge devices. If these are brushless fans, don't ever go "reverse". $39.90 and you are done!http://www.dfrobot.com/index.php?route=product/product&path=52_104&product_id=844#.UfW8rjzD_UA
I would use the arduino, and a relay board with 2 relays. Not as expensive, and more "arduino".How are you going to decide when to turn the fans on?