Hi guys…
I want a good and powerful usb fan.
I see a lot of chinese crap… but dont know about a good one…
I already own the arctic cooling breeze… but I need something bigger and with more power…
yeah… I know better look a desk fan powered via mains… but…
I need a usb powere one.
Any idea?
Thanks
You could build one quite cheaply using a USB step up module to get 12V from the 5V supply, powering a couple of 80mm or 120 silent fans.
Yes… I already did it… th problem is that most big 120mm or bigger ones need more curent so the dc dc boost board needs a lot of amps from the 5v usb port and that is the problem…
I mean… boosting from 5v to 12v requires a lot of amp draw specially if the dcboost board has low efficiency as the cheap chinese boards from ebay.
if you read specifications… most of them when boosting from 5 to 12v can deliver only about 300mA at 12v while are drawing more than 1A from the 5v supply. I tested. Also I can hear a lot of noise coming from the inductors of the board…… and the 5v rail input drops to about 3volts due to the high current draw…
and it happens with 3 different boards…. 2 of them with different main chips…
and also from different 5v usb power supplies…
I know some of the cheaper modules can be not so good near their limit. You could use a 12V DC power supply and skip the USB altogether? Another idea is to use PWM and run the fan at slightly less than 100%.
Are you using a desktop or a laptop? If laptop, I can’t really help you but if desktop it’s really easy to connect a powerful fan to your power supply.
You do realize 5vdc is the highest current produced by a computer power supply
If you look at the specs, the 5vdc even on anemic and crappy 300 watt power supplies push 20-30A at 5vdc, and 12vdc at 10-15A
You can easily tie into an unused molex plug and you have pins for both 5vdc and 12vdc and quite well regulated too
http://www.wegotserved.com/2008/10/19/extending-your-computer-power-supply/ <- just a link to give you ideas if you ever need to pull power out of a computer