Question Do volts add up in fan headers or remain the same?

[Adonis180]

So if my mobo fan header has a max power of 12watts & 1A and i plug in three 12v fans in that same header using a fan splitter. Does that mean 36v will be flowing through that header if i set fans to max speed using PWM?
Is that how it works?
In this case each fan’s max input is 0.18A and max input power 2.16watts.

or will the header remain at 12volts while running each fan at its max 0.18A & 2.16watts? So 0.54A and 6.48watts in total. Which would be okay for the header since its not over 1A and not over 12w

 

[zinkles]

Does that mean 36v will be flowing through that header if i set fans to max speed using PWM?

NOPE! It is in parallel. This means the same voltage is used but the current flow triples.
(it is pretty self explanatory, because typically, the motherboard is only given 12v to work with [almost always] so the fans must be powered with 12v and not 36v)

Since the mobo gives the fans 12v the fans are in parallel.

If, for example, lets say that you take a 36v output and then you want to run 3 12v fans, you can wire them in series, so its divided among the 3 fans equally

Learn about 'Series' connections and 'Parallel' connections here 😀

 

[Adonis180]

NOPE! It is in parallel. This means the same voltage is used but the current flow triples.
(it is pretty self explanatory, because typically, the motherboard is only given 12v to work with [almost always] so the fans must be powered with 12v and not 36v)

Since the mobo gives the fans 12v the fans are in parallel.

If, for example, lets say that you take a 36v output and then you want to run 3 12v fans, you can wire them in series, so its divided among the 3 fans equally

Learn about 'Series' connections and 'Parallel' connections here 😀

So the header remains at 12v. And the fans at 0.54A and 6.48watts in the example i gave right? Since you said the current triples?

 

[zinkles]

So the header remains at 12v. And the fans at 0.54A and 6.48watts in the example i gave right? Since you said the current triples?

Yes, your example is accurate.

 

[Paperdoc]

Yep, as zink_boi explained, the max Voltage is constant, and what changes as you alter the number of fans connected is the max CURRENT (amps) the group of fans uses from that power supply. But all of that is under the conditions you specified: the system is set to give only max speed. In virtually all such computer cooling systems the fan speeds actually are changed by the mobo in response to temperatures measured in the right places, so you get all the cooling needed for the whatever the current workload is, but not too much cooling that just wastes energy and fan lifetime. There are two different methods of changing fan speeds depending on what fan design you have. Do not worry about those details, though, the basics still are the same.

One common conceptual "model" to help understand electric power flow is water flow through pipes and hoses to devices on the end. Suppose you have a garden hose tap on the side of the house. You buy a few hose tees and connect them together so you can feed four different hoses to four different sprinklers (of the same model) from that one tap. When you turn the tap on, all four hoses and sprinklers get water supplied at the same PRESSURE (the force that makes the water flow, analogous to electrical VOLTAGE), and the total FLOW rate in gallons of water per minute (analogous to electrical AMPS) from the tap is just four times the flow rate of one sprinkler.