Hellfire90
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Joined: Sun Sep 08, 2013 9:35 pm

info about power supplier and cooling fan

Sun Sep 08, 2013 9:39 pm

Hi! I'm about to buy a Raspberry Model B with a 1.2A power supplier. I wish to use a cooling fan that will be powered from the USB. it's a 12V 0.23A fan, I assume that it will drain less current at 5V, am I right? Will the supplier be enough for powering both the raspberry and the fan? thanks for the help!

W. H. Heydt
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Location: Vallejo, CA (US)

Re: info about power supplier and cooling fan

Mon Sep 09, 2013 5:04 am

Ummm.... What are you planning to cool with the fan? Yourself?

Real answer: The Pi doesn't need additional cooling. Allowing air to circulate around it (even inside a case) is sufficient. These sorts of processor chips are designed to work inside cell phones, so they're real happy with all that air that can move around.

itimpi
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Re: info about power supplier and cooling fan

Mon Sep 09, 2013 6:08 am

It also seems to me that if the fan is designed to work at 12V there is reasonable likelihood it will not work at all if given only 5V via USB.

Hellfire90
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Joined: Sun Sep 08, 2013 9:35 pm

Re: info about power supplier and cooling fan

Mon Sep 09, 2013 7:13 am

I tested the fan and it works at 5v. I am going to leave the PI turned on 24/7 as torrent box, that's why I thought about a fan..

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rpdom
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Re: info about power supplier and cooling fan

Mon Sep 09, 2013 7:34 am

Hellfire90 wrote:I tested the fan and it works at 5v. I am going to leave the PI turned on 24/7 as torrent box, that's why I thought about a fan..
You still don't need one though. Not unless your room temperature is above 50°C, or you have the Pi in a totally sealed case.

Yes, the chips can get a bit warm, maybe uncomfortably hot to the touch, but they are rated to handle much higher than that like many other chips. Just you don't get the chance to touch most other chips.

Hellfire90
Posts: 3
Joined: Sun Sep 08, 2013 9:35 pm

Re: info about power supplier and cooling fan

Mon Sep 09, 2013 8:35 am

Ok I got it. Thanks very much for your help!

boyoh
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Location: Selby. North Yorkshire .UK

Re: info about power supplier and cooling fan

Mon Sep 09, 2013 9:43 pm

Check the speed of the fan on 12v
Now check the speed on 5v
I think the only cooling it will be doing
Is the fan It's self, and not Pi
BoyOh ( Selby, North Yorkshire.UK)
Some Times Right Some Times Wrong

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Offcenter
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Joined: Wed Jul 31, 2013 4:57 pm
Location: Northwestern New Jersey USA

Re: info about power supplier and cooling fan

Mon Sep 09, 2013 10:12 pm

I'm no expert, but....
It has been my experience that low voltage burns out motors.
(lost a DC starter motor and a AC refrigerator motor that way.)
Maybe someone who knows more can comment on this.
George in New Jersey.
(learning a little bit every day.)
(and darned confused most of the time!)

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