Fan power

olrac · 10-24-2009, 01:29 PM

I have 2 fans like this:
http://www.newegg.com/Product/Produc...82E16811999029

I don't want to use them with my PC, rather I am considering using them to cool the cabinet where I house my NAS and some other devices.

If I daisy-chain the 2 fans, would I need just an adapter like this:
http://www.newegg.com/Product/Produc...-011-_-Product

to power them?

**Tyree** · 10-24-2009, 03:09 PM

That should work fine.

olrac · 10-24-2009, 06:02 PM

Awesome. Thanks.

I don't know much about electricity. If I wanted to add additional 12V fans, how many would that adapter power safely? How would I calculate the needed specs of an adapter for x # of fans?

olrac · 10-24-2009, 06:56 PM

And while I'm at it...

I'm thinking that I could also throw a light of some sort into the mix to be housed within the cabinet, but it would need to be switched.

Assuming I use an unswitched 4-pin LED (or something similar), what kind of switch would I want to add, and what kind of connection would I need?

If I use an SPST switch, for example, what kind of adapter or connection should I seek?

I'm thinking Power adapter -> Fan 1 -> Fan 2 -> (?) -> SPST switch -> (?) -> LED

So what would go where I have (?) ???
Or am I thinking about this all wrong?

gcavan · 10-25-2009, 12:13 AM

Quote:

I don't know much about electricity. If I wanted to add additional 12V fans, how many would that adapter power safely?

Fans will be either marked with voltage ( E ) in volts and current draw ( I ) in amperes or power ( P )in watts. The formula to use is.

P = E I

So using the fan you selected:

E = 12 volts, P = 4.8 watts.

So I = 4.8/12 = 0.4 amps

Your adaptor is rated at 2 amps, so arithmetic says you could power exactly 5 of those fans. It may well do that but I would be surprised if it lasted very long. You would be good with 3 or 4 of those fans

Quote:

How would I calculate the needed specs of an adapter for x # of fans?

Total up the current draw of all devices you want to power, add 25% or so for wiggle room and select a supply with a rating of at least that.

[LED's]

LED's need a negligible current to operate, but, like all diodes look electrically like a short circuit, so you will need a current limiter resistor wired in series with it. In a 12 volt circuit, that needs to be about 500 to 600 ohms. You may be able to find a LED light with this already taken care of for you.

Take a look here for an LED how-to:
http://www.instructables.com/id/LEDs-for-Beginners/

10-24-2009, 01:29 PM	#1 (permalink)
olrac Registered User Join Date: Feb 2009 Posts: 21 OS: Vista	Fan power I have 2 fans like this: http://www.newegg.com/Product/Produc...82E16811999029 I don't want to use them with my PC, rather I am considering using them to cool the cabinet where I house my NAS and some other devices. If I daisy-chain the 2 fans, would I need just an adapter like this: http://www.newegg.com/Product/Produc...-011-_-Product to power them?

10-24-2009, 03:09 PM	#2 (permalink)
Tyree Mentor Hardware Team Join Date: May 2009 Location: Illinois Posts: 5,363 OS: XP Pro-7RC-Mandriva My System	Re: Fan power That should work fine. __________________ Posting your PC specs will help us to help you quicker and more efficiently.

10-24-2009, 06:02 PM	#3 (permalink)
olrac Registered User Join Date: Feb 2009 Posts: 21 OS: Vista	Re: Fan power Awesome. Thanks. I don't know much about electricity. If I wanted to add additional 12V fans, how many would that adapter power safely? How would I calculate the needed specs of an adapter for x # of fans?

10-24-2009, 06:56 PM	#4 (permalink)
olrac Registered User Join Date: Feb 2009 Posts: 21 OS: Vista	Re: Fan power And while I'm at it... I'm thinking that I could also throw a light of some sort into the mix to be housed within the cabinet, but it would need to be switched. Assuming I use an unswitched 4-pin LED (or something similar), what kind of switch would I want to add, and what kind of connection would I need? If I use an SPST switch, for example, what kind of adapter or connection should I seek? I'm thinking Power adapter -> Fan 1 -> Fan 2 -> (?) -> SPST switch -> (?) -> LED So what would go where I have (?) ??? Or am I thinking about this all wrong?