DIY Cooler Help.

Hello, I want to make myself a laptop cooler for a possible summer project. Now, I am not an electrician of any kind, but do know how to solder somewhat well.

What I need help on is how to power my fans. I have found 12v DC Power Supplies, but I do not know what specs I need. I want to run 2 fans connected to each other, so I will cut the RPM wire of one fan and solder the red and black wires to the corresponding wires on the second fan. That way, my fans are powered by one connection.

With that way of connecting fans, how many volts and amps will the fans draw? To make it simple, I will use 12v fans that draw a max of .5 amps (just an example, don't know what fans I will really use.)

Also, are there other ways to run 2 fans with one connectiong which would be better than my current way?

 

What don't you try using a variable power supply for testing purpose?

 

Hmm...I'm not understanding what you're trying to say. Could I get a easier explanation, please?

From what I can gather, you want me to use a power supply to measure out what voltages and amps I need. If that is right, I would use a multimeter and try to measure the voltages and amps coming from the fans, right? Also, a PSU from a desktop could count as a variable power supply, right?

Sorry, I'm new to this electrical stuff. Please be patient with me.

 

The way you would connect the fans, would require a power supply of 12volts at 1 amp.
When you connect the fans the way you are saying, red to the two reds from the fans, and the black to the two blacks from the fans, you simply double the amperage, and keep the same voltage.
It is a veries simple circuit.
Make sure that the voltage of the power supply is less than or equal to teh voltage of the fans. If the power supply voltage is higher than that of the fans, than you would need to add resistors and or potentiometers to the fan circuit.

K-TRON

 

Alright, thanks for the help there K-Tron.

Now, what would happen if the amps the power supply can deliver is higher than what the fans need? I understand the voltage part, but does the same apply for the amps?

 

It is ok if the amperage is higher, it will only supply what is needed. If you use a power supply that doesn't supply enough amperage, however, you risk burning the power supply up.

 

Alright, thank you guys for the help! You guys get a reputation point!

 

like me u r at a disadvantage of not having expertise in Electrics.
So why dont u give ready made Coolers a try.


buy some cheap ones...if they suck...take out their motor & modify them

 

I plan on making a computer case this summer. With that, I will probably have some spare material left over, which I assume can make a laptop cooler.

I could probably buy myself a cooler, I do have the money. I just choose to spend it on something I can learn with.

 

Thats what i am saying ..
buy the cheapest cooler...basically u ll get an idea how it works..

use its parts & modify it.

why i am saying is...coz if u buy your own parts...it will cost u more than the actual cooler.

 

When I am building it off left over parts, I doubt that I am spending more than the actual cooler.

I do have enough understanding of how to wire up the fans, build a switch and how to power it now. I am pretty sure I do have some left over power supplies from old stuff which I could use, too.

 

I think there's a problem. It's been well over 10 years since I've done any kind of electrical calculations so keep that in mind.

Schematic of a simple situation:

A --- Fan --- B

A and B are the two connectors of the fan. If you put a 12V power supply between A and B the potential drop from A to B would be 12V. Yay! That's what you want.

Your plan:

A --- Fan 1 --- B --- Fan 2 --- C

B is the point at which the two fans are connected. If you put a 12V power supply connected at A and C the potential drop from A to C is 12V. But the potential drop from A to B and from B to C is not 12V. If the fans are exactly the same, the potential drop would be 6V in each case (6V + 6V = 12V). From the standpoint of voltage, it would be the same as connecting each fan to a 6V power supply: undervolted. If you do conduct an experiment with this circuit, the fans will run (I think) but they won't run at their full capacity.

The other problem with connecting them in series is that if the wiring in one fan fails, then both fans stop because the circuit is broken. Plugging them in parallel prevents that. In parallel, if one fan fails, the other one can continue to run.

It should really not be hard to set up a power source with 2 connectors in parallel.

 

do the abc thing in paralell

glad you made this most, im wondering the same thing.
i got a notebook cooler from ebay (yay) because its alluminum, at was 5 bucks eheh
it has some really nice "vent" cuts on it, but the fans are like, 500 rpm nail polish driers. my plan is to nab a couple of 120mm case fans and hook them up to it.

the fans are 12v, 0.350 amp. i want three fans total (gpu, cpu, hdd)
so in a parrallell circuit, is it 12+12+12 = 36 volt power supply with 500ma rating?
or is it 12volt with 350ma*3= 1050ma (1amp)

i want the fans to run at least 90% full speed, i will be adding a throttle to it as well.
so what power supply is needed, and is there a "better" name for the "throttle" ?

 

I'm not understanding the diagram. This is what I plan to do with the fans in the attached image. I thought I would only need 12v for my wiring, but I do not have a clue how the voltage will be spread.

The only electrical work I've done has been with batteries, and I don't know how to apply it to this.

 

ok, so i did some reading.
paralell circuit is easier/cheaper (power supply wise at least)
3x 12volt fans @ .48/480ma = 8.4ohms /17.15 watts
so i need 12v ac dc 1.43amp (1500) power supply
i plan to just get a universal ac to dc adapter at radioshack for 10 bucks, and use an old toggle switch i have laying aorund somewhere eheh
now i just need to figure out what to use as a base

 

This sounds like a lot of fun. I've got enough on my plate though. I'm trying to pound out all three of my MCSE core exams before the end of the summer.

 

*looks at sig*

Fun times. I don't regret spending the time to make a cooler that really works. Temps are bearable now

 

Your guide was what I based most of my info off of! The wiring of your guid confused me though, so that is why I made this thread It is a great tutorial and does provide great info.

 

I would suggest that you find a basic guide on the principle of electric circuits and learn the basics. It's really not that hard. The diagram you included shows two fans in parallel. That's precisely what I suggested you do. Whit that kind of circuit, if both fans take 12V, then you need a 12V supply. The only thing you still need to consider is how much amps those two fans will take in parallel and how many amps your power source can supply. If I recall correctly, the total amperage of a circuit consisting of two devices connected in parallel is the sum of their individual amp ratings.

 

Well, all my questions have been answered. The fans in parallel was my original idea anyway, I never wanted to go into series.

Anyway, thanks for all the help.