If I have a 12v 0.14amp Fan from a computer case and want to run it lets say not in a computer but for another purpose can I use a 12v 1amp transformer to run it? I guess my question is although the power supply has more amps than the required amount for the fan will the fan just draw out the amps it needs to run on or does the power supply push out all the amps into the fan and overload it destroying the fan? Any feedback appreciated

DC fans base their power consumption on avaliable voltage. The amps of the supply mean nothing. You are safe in doing what you say.

Cheers johnoh I'll go ahead with it. Thanks

G'day, You are talking about a DC power supply aren't you. Is it regulated? If it's just a transformer you will only get AC. If it is DC at 1A then if it's not regulated the output could be a lot higher than 12V at a lower output of 140mA. This may or may not affect the fan: it will run much faster at best; burn out at worst. If you want to check it out put a resistor of about 100ohm across the supply and see what voltage you get (12 @100R I=120mA)If it's still 12V then the supply is most likely regulated. Good luck, Elric

In your given scenario, I am inclined to say yes, Although I strongly disagree with John's comment. Power consumption of the load is not merely based on voltage, but current no less. Note that power equals voltage x current. Voltage is a given factor, you have to match it. Ampacity(current) determines the capacity of the transformer and how much load it will supply. A 12V, 1A DC converter will not replace a 12V car battery to supply the same load(An exaggerated analogy) A power supply has to have higher current rating than the load. You may not understand Elric's theory on regulation if you are not the "electrical type" of person. There are two types voltage regulation. Voltage regulation of the transformer is equivalent to effieciency, but numerically opposite, the lower the regulation, the better. Regulation of the DC power supply refers to the stability of the output voltage. Both of them however deal with changes of no load and full load value. My advice? Try it!

Vince - this post would appear to have become somewhat technical,perhaps needlessly so. In an attempt to simplify:- Volts x Amps = Watts a) Volts - the voltage supplied and that required by the device/component in use should be the same. b) Amps + Watts - these relate to power, again supplied and required. That supplied should be equal or greater (much better) than that required. Otherwise the supply source can be damaged as too much power is being drawn from it. It does not matter that the supply exceeds the required, as the device only uses what is required. When a number of devices are used, add the wattages together to see that together the supply wattage is not exceeded. Hope this is of some help. Good luck -keep us posted.

Simply put : The load that your fan puts on the power supply will determin what amps are actually drawn by the fan.