The ultimate beginner's guide to PC FANS

[FlyinHawaiian]

Man, don't read all that, you must be nuts!

lol, dunno how but I did it, took me like a week and I know I didnt comprehend all of it but alot I did. Great thread Ninja!

I salvaged two 120mm pc fans from a quality blueprint printer that was being thrown away,I cant find any info online about the fans they have 3 wires red,black,brown what could this brown wire do? the fan runs w/o the brown connected but im still cerious maybe a speed controll? heat sensor? rpm? ground? lol

I bought a 12v 1.5 amp radioshack AC to DC adaptor like 2 yrs ago for $35! only used it for 6 months powering two .38 amp fans then it sat in my drower and now it doesnt work what a POS! I only paid $35 for it cuz I thought it'd last forever lol.

Oh heres somthing weird do you guys ever check the volts output with a mutimeter? I just bought a 12v 1.2 amp ac to dc adapter at salvation army plugged this fan in and was like woah this fan has some power! then just for the hell of it I checked the volts with a multimeter and this 12v adapter puts out 18 volts! no joke lol Im glad they didnt blow. I suggest you guys check the volts on your adaptors, multimeters are cheap and very usefull.
Merry Christmas!

 

[ScrubNinja]

Hi Flyin cheers. That's strange . I tried looking too - couldn't find anything useful. I have no idea but my guess is the brown is rpm monitoring or control. That's pretty freakin wierd with the voltages, man no idea what's going on. I hate when you guys stump me like this, lol. I have a cheap multimeter but it's fused for 200mA max so from my little understanding, it's useless for much that I wanted it for.



Or is the 10A setting what you're talking about?

 

[FlyinHawaiian]

hmm well now its 16.70 volts lol coulda swore it was 17-18 earlier.
my multimeter is fused at 200ma too but when I tested the voltage on the adaptor I didnt have anything running on it so I dont think any amps were going through the multimeter, I could be wrong Im not too savy when it comes to electricity but im learning. I used setting 20VDC on the multimeter which is 3 clicks to the left on both our meters.

this adaptor is kinda big and heavy and it says class 2 transformer on it, not sure what that means.

 

[ScrubNinja]

Spooky dude I think Class 2 is slightly different inside with the grounding - check this out if that explains anything. I'll try to find a tutorial or something for checking the voltage. I know you can check the amps like this. (just exchange ccfl/inverter with "fan" I guess. St8 dropped a lot of science in that thread, but a lot of it relates to ccfls and a lot is over my head. Let us know how you get on.

 

[ScrubNinja]

Hah! I found out the reason bro!! And found a good tutorial too. Scroll down to Example 2: Testing wall wart (adapter) plugs

Yow! 14V? That's not anything like the 9V on the package, is this a broken wall wart? Turns out, its totally normal. Transformer-based wall adaptors are (almost always) unregulated, which means that the output is not guaranteed to be a particular value, only that it will be at least what is printed on the box.

Another mystery solved

 

[BC Chronic]

Hey Scrub! Thanks for directing me to that sidewinder fan controller! Pretty cool I must say...I know you gave me that advice pages back but I forgot to thank you...
Merry Christmas

 

[ScrubNinja]

No probs BC, enjoy

 

[FlyinHawaiian]

Hah! I found out the reason bro!! And found a good tutorial too. Scroll down to Example 2: Testing wall wart (adapter) plugs



Another mystery solved

wow thats interesting thanks for the find ninja! good tutorial too, I guess I could wire 2 fans in series for 8ish volts, I think the volts jump around a lil bit tho on these transformer adapters, maybe better to find a non transformer adapter it was only $2 at salvation army anyway.

 

[ScrubNinja]

Yeah it was interesting! I've always gone for the heavy adaptors when available, on the assumption they must be better quality or more rugged inside. It explains a lot of past confusion for me. I tested my regulated supply and it was all good. It actually put out just below the voltage it says, but that's probably just my crummy multimeter.

Now I know how to check batteries too - Handy!

 

[ScrubNinja]

For those following the carbon screen thing, Scrubbalubs got his greasy mitts on a pile of those holder upperers today for free. There were hundreds in a pile in the forest.

 

[OBK]

Cool find in the forest!

Just a little update on my cab setup-- the sunbeam rheobus extreme is performing great. Only thing is, as you pointed out earlier in the thread Scrub (or maybe it was mj) is that these electronics come with their own costs. In the case of the sunbeam controller, it definitely generates some heat off of it. I laughed when I first saw how big the cooling fins are on this controller, but as my fingers can tell you, it uses those fins!

It also has two BRIGHT BLUE LEDs shining through each knob, putting out a bunch of light that creates its own trouble. I thought about just snipping the LEDs, but they don't look very accessible. So for now, I just made a small cardboard box with passive intake and exhaust holes to contain the light. Works fine, but kind of bugs me to have to shelter a controller that I know generates heat. Any ideas? Maybe electric tape on the knobs?

One cool thing the controller works great for is a dimmable green LED for nighttime illumination (yeah I know... but sometimes one just has to get in there for something). Just searched 'green aquarium led' on ebay, picked up a cheap 12v one (waterproof too!). Hooked it up to the sunbeam, and it works great! It dims very smoothly, allowing just bringing up the minimum amount of green light as needed (don't wake the plants!). A good use of a controller channel IMO, if there's a spare one available.

Somehow in the excitement of trying out the new controller, I seemed to have killed a new 2amp Delta. Don't think it was defective, feels like 'pilot error'. Are there any precautions to take with hooking up these beasts? I always figured like any pc fan, it was OK to try hooking up wires one way, and reverse if the fan doesn't move. Now I wonder...hmmmm.

 

[ScrubNinja]

G'day OBK! Hey man, I'm not a big LED nerd, but beyond my normal distrust of green lighting, I would be very careful with those! Me personally, I would buy the highest quality one I could find and investigate it's SPD (spectral output) beforehand. From my understanding, a lot of LEDs (and I'm thinking the cheap ones mostly) put out more than one specific nm or range of light. Check this page, it illustrates it better. Specifically check this green LED's output. I see some blue there, and I'm assuming that was for a good quality LED.

Maybe ask in the LED club, see what they think? You could also stand in a dark room and look at the reflection in a CD. At just the right angle it will show you all the colours making up the light. I have a blue LED on a speaker and that gives out blue, red, violet, green.... So please ask an LED nerd and see what they think.

With the fan controller LEDs, I found a few discussions online for mine about customizing it, switching out the LEDs and faceplates etc. I kind of like em

I would try to place the rheo fins in the exhaust flow if ye can. As far as I'm aware there's no probs testing the wiring in the wrong orientation with 12v. I just brush them to play on the safe side. With something like a delta though, I would concentrate and just get the wiring right first time by checking the plugs/colours. More to the point, I don't do any wiring where my speed controller is involved, I use the standard connectors so I don't have "issues". Hope it helps

 

[OBK]

Hey Scrub, thanks for the heads-up about LEDs, guess it's not worth the trouble or risk. I will learn to let the ladies slumber. Oh well, another toy for the "should have run it by ic before buying" drawer. But that's what I'm here for, the learning.

And cool tip about using a CD to suss out the colors on the light.

 

[ScrubNinja]

No probs man, I think StealthDragon gave me that tip You can go nuts and google a diy spectrometer or spectograph too. Knna has made some great posts about lighting. Here is the best single thread I've ever read about lighting.

Note that although the higher reflection is of green (around 550nm), and thats why see the plant green, just a small fraction of green is reflected back, as 15%, and not all as you can read many times on the net.That plants reflect back all the green light is a false statement.

This false statement is found very often linked to other false one, that plants dont use green photons for photosynthesis. Plants reflect back more green photons than of other wl, as they use them with lower efficacy, but as max its used at half the efficacy of red ones. Lower efficacy of green, yes, but its not wasted at all. That green light is wasted is another false statement. Ill analyze this topic deeper later, as its qualitative and not quantitative analysis.

Ok, ok, I'll stop now Best of luck!

 

[FlyinHawaiian]

I told myself i'd never buying a radioshack adapter again, well I lied I just found an adjustable wallwart adapter thats DC 2.5A 6, 7.5, 9, 12 volts on sale at radioshack for $9.99! reg price was $47.99. Im stoked as I was just about to order a 3A adjustable power supply like the one scrub has, but this is litterally perfect for my needs.

half the adapters they had were on sale 60-80%off, whoknows maybe they could be on sale at your radioshack.

I was there for somthing else but somthing told me go look at the adapters, even tho I was there 1week earlier looking at them w/o the sale thinking that would be a sweet adapter to have, I was almost tempted to pay the $47, lol ok enough rambling I just wanted to share that.

 

[ScrubNinja]

Great score!

I ended up disconnecting my fan controller and running my tent's Delta exhaust straight off a wall wart. I think it's 6v and it works great.

 

[piosh]

Amazing and inspiring thread dude. Lovin it ,altough Ive just started to read it.
Rly like your work.
Personally Im using

2x

54,7cfm
12V/0.13A
10,5 dB
no static pressure parameter given by producer

and

2x

62,something cfm(I think)
also no many statis given by producer

powered by two delta electronic adapters 1,3 A each. Working great , its at least enough to cool my tent with 2x 150W hps.

Explain me pls whats better for using carbon filter:
this:

or this way:

(probably its somewhere here but I still havent found)
thx and K+ for inspiring thread.

 

[ScrubNinja]

Thanks piosh! Well, in the second pic the fans are stacked directly so that's a no-no. But if we pretend that only one fan is used at each spot, then that's what my actual setup looks like. One pushing into the filter, and one pulling.

Personally I think that way is best like I do it. If we say that the problem is when one fan is interfering with the other, then having a carbon filter between them like I do is going to ensure there is no problem with that.

I'm no scientist so I don't know how deep the problem extends. But in the first pic, the first fan is going to create a circular flow through the spacer, like a corkscrew kind of flow. The blades of the second fan are spinning the same way so I suspect that could contribute to a little efficiency loss. Like, if you imagine that the second fan was spinning in the opposite direction, you can see it would work better, right? I think so anyway. Peace

Edit: In other words, the way I have it, the fans are assisting each other to get through the filter, but their circular flow pattern is not interfering with each other.

 

[piosh]

what do you think about putting inline for ex. 3 fans (30 cm distances beetwen each , at one ventilation pipe) to increase efficiency and keep "stealth issues" at maximal level - im actually trying increase my light power w/o increasing noise

 

[ScrubNinja]

Yes that should work fine. I found this on the net, maybe it helps, because it will be a little louder than if you had one fan:

Sounds are additive, but not in a simple linear way.

* Two 30 dB noise sources make 33 dB
* Four 30 dB noise sources make 36 dB
* Eight 30 dB noise sources make 39 dB
* Sixteen 30 dB noise sources make 42 dB