solar panel to power a cooling fan.

[Jag300]

Hi there, I have a Nikkai 2.4w solar panel battery charger as supplied from Maplins. My question is can it be used to power a computer cooling fan, and is it just a case of hooking up positive to negative ?.

 

[C12Friedman]

Most PC fans use brushless motors which use a brushless motor controller to enable the operation of the motor so in most cases you would not be able to directly power a PC fan. If a direct DC charge is given to the fan, it will only twitch some (needs directed pulses to operate)
Here is an article about brushless motor control http://ww1.microchip.com/downloads/en/AppNotes/00857a.pdf by Microchip titled "Brushless DC Motor Control Made Easy" (at 48 pages, I'm not so sure about "Easy" but it does cover the principals in the first few paragraphs).
Adding a motor controller to the mix should work but may not be ideal though since there will be some voltage drop caused by the controller itself (likely a fan would still work since most can start with voltages as low as 7V and a few others even down to 5V). I would consider it a project at this point rather than a solution, once it works to your satisfaction, then you could consider it a solution.
One other possible issue is the rating of the solar panel, a 2.4W solar panel can only produce that level of power in full sun, less sun, less power available - I think two panels in parallel would provide the current needed

 

[hunter315]

It really depends what voltage the panel outputs, you need to get it into a range that the fan can work with, somewhere 5-15 should work for your purposes.

[strike]C12Friedman, I don't know what got you confused, but PC fans are standard brushed DC motors, they don't need a fan controller, i have a couple in my case connected straight to the ground and +12V lines on my PSU via a molex connector, they don't need a controller.[/strike] Fan controllers in computers are either PWM controllers or have a little rheostat for controlling fan speed, they aren't any fancy electronics.

Edit - Today we learned that they do need a controller, its just built into their fan hub!

 

[C12Friedman]

It really depends what voltage the panel outputs, you need to get it into a range that the fan can work with, somewhere 5-15 should work for your purposes

In re-reading some fan articles I found that is correct - see below

C12Friedman, I don't know what got you confused...

Perhaps this article http://www.hardwaresecrets.com/article/Anatomy-of-Computer-Fans/1039/2 but the sensors and electronics needed can be mounted inside the fan hub which would allow direct DC power to work - unlike the smaller, higher torque motors I'm used to working with which do require an outside controller source.
Summary: Yes the fan is brushless but since the controller is built in, shouldn't be an issue (except for sunlight efficiency)

 

[hunter315]

Interesting, I knew they could run off straight DC so i had assumed they were brushed, i hadn't considered them building the controller into the hub, thats a neat little trick! I guess we both learned something today!

 

[C12Friedman]

Funny how I never even considered the controller aspect (while knowing full well I was using a brushless fan) and plugging straight into molex - now that I consider it, Doh! I don't even want to go into that part of my psyche that may have allowed me to simply accept it.

 

[zaramcCarthy]

You need to find a reliable approach to store your energy following it is made by your solar energy program. A battery can retailer this excessive vitality, or you could also sell the extra to your business that keeps a main strength grid.

Make sure you put in your solar power panels so that they could get optimum exposure to the sun all through the year. Examine the sun's route all on your own to see precisely what region of your residence will get the most regular exposure to the sun when you have questions regarding Gem Energy placement.

If you don't imagination an investment, it can save you a ton of money with solar technology. The installation of solar panel systems requires a significant expense, so years could complete ahead of the panels make ample price savings to protect your expense. Solar power panels will not be a smart investment in case you are not able to compromise inside a particular residence.