Watts vs. Volts: Installing a 'nonstandard' fan

[Bacchus]

I got my hands on a pretty powerful fan (intended as my intake), but the plug on the end of it is different than that which can be accomodated by my MB's 3-prong plug.

The fan I'd like to install is a 12V/4W fan (or, at least I *think* its 4watts).

The connector on the end of the fan has 5 holes in it, but it has only three wires running into it (black, red, and yellow).

I'm assuming that, given these three wires, I can simply hack-off a three-prong connector on one of my other fans.
BUT...my concern is wattage/voltage (again, I'm no electrician, and therefore don't understand/appreciate the real difference between the two).

Assuming my MB has a 3-prong connector available to accomodate an extra fan, and assuming I'm using a 350w power supply, do any of you see any problems with what I'm attempting to do here? And if so, would you recommend another way of doing it or another thing to check? I'd hate to blow-out this fan.

My thanks in advance.

 

[Bacchus]

Taking this line of thinking even further, is there some schema for how a power supply provides electricity?

I've heard an easy-to-remember analogy, comparing it to water running thru a hose....where volts is the speed of water, amps is the diameter of the hose, and watts is how full the container gets (volume).

Do power supplies provide *X* amount of volts/amps/watts thru each connector? Do the 3-prong plugs on MBs provide *X* amount of juice thru each plug?

 

[ksallen]

Not positive about your problem, but here's a free bump, and while I am at it:

Volt = Joule/Coulomb = energy delivered per coulomb of electrons
Watt = Joule/Second = energy delivered per unit time
Current = Coulomb/Second = 1 AMP = Watts/Volts = how many coulombs of electrons move past a certain point in a second
Watts = Amps*Volts


**1 Coulomb = 6.26x10^18 electrons
***That analogy doesn't really work

 

[ksallen]

From my understanding, the power supply provides a constant voltage, and that is all. However, it must vary the power (watts) to maintain that voltage. On fans that I have, they have written on the an amp rating. That means that the fan will draw however many amps, at the voltage it is connected to, requiring (the amp rating * voltage applied) watts of power. This is all basics on physics knowledge, not fan knowledge, so hopefully someone will help me out.

btw, that analogy is somewhat okay if you understand the source of the speed of the water. To make water flow faster through a hose, a greater pressure differential must be applied to each end. Example, if you had one end of the hose in the atmosphere, and the other end at two atmospheres of pressure, the water would have one speed. Now increase the pressure at the second end, and the speed increases. This pressure differential is what volts most closely resembles, not the actual speed of the water.

 

[nam ng]

Do not attempt using a 4W fan with MB provided fan headers, generic MB fan headers only capable of ~2W, they will burn out using 4W fans.

 

[Dulanic]

nam ng is correct, don't put it on your MB. Most newer MBs can handle 4.2W or so through the MB headers... 4W is too close for comfort.

 

[evergreen96]

here 1 suggestion,

using a power strip, connect all "Pc realated Power cord," this will be your on off switch for the fan.

Go to Radio Shack/Target and pick pick up one of those universial AC/DC power supplier. Choose the approiate amps, volts and simply connect the raw power leads.

 

[Ark]

Don't use MB connector - you will burn MB.
You must use one of the connectors like harddrive/cdrom uses.
use spare one or you can buy Y-splitter in any computer store.
Make sure you connect only power wires from the fan (black and red) to 12V supply.
Usually Black wire is common,
Red wire on the fan will go to yellow wire on the connector (12V- must verify with meter).
Yellow wire on the fan normally is speed sensor (verify) - don't use it.
Red wire on the power connector usually is 5V supply.