12v cooling fans

[subman]

Originally Posted by mike31154

That is 250 milliamps. 0.250, take it to 3 decimal places for milli which means thousandths, which is what the 3rd decimal place designates.... or a quarter of an amp, if you wish. Never a bad idea to get a power supply that has a good buffer of extra capacity (within reason). More efficient and less heat produced by a larger supply running at less than full capacity, than a small one trying to put out its max power. Not to mention, safer.

He only wants to run 2 so thats a 50% buffer thats pretty good

[midgetwaiter]

Do you know if that is a regulated power supply Doug?

A regulated power supply will deliver 12v at anything up to it's rated current. An unregulated power supply, which most cheap ones are, will only deliver 12v at exactly it's rated current. If you are drawing a smaller amount of current the voltage goes up.

In your situation I would expect your power supply to deliver something more like 14v at half it's rated current. This is not a big deal from a safety POV but I've noticed that it tends to make the fans noisy if they are driven too hard. You can just add a resistor to the circuit if you need to match the current draw.