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48v fan

J

jtoone

n00b
Joined
Apr 18, 2008
Messages
9
I have fun building and rebuilding odd cases using a couple of old Lubic sets (if you remember those).

Anyhow, I happened across a beefy 48v fan (28v-56v) I'm thinking of strapping into this thing, just for the sheer audacity of it.

The question, should I fear any EM problems by putting a used 48v electric motor next to my computer and lcd monitor (I'm mounting it to the case using a wall bracket)? Anyone have a cheap way to test it?
 
Better question is not AC or DC but is it brushless? That's your best hope for low(er) EMI, but there is no real way to "know" without testing it out.

What are these fans out of?
 
Here' much better info (yesterday I had it in my hands about 15 minutes before posting).

Papst 6248/4

http://www.ebmpapst.us/allpdfs/DV6200.PDF

Considering this seems to be a $50-$100 fan (got it for $5), I'm feeling more confident.

The highest output transformer brick I could get my hands on right away was a 30v, but it's in the range (28-56). I'd like to get a higher output one and put a pot on it.
 
Forget power bricks, potentiometers and voltage regulators, the fan is taking 40W, most potentiometers work with ~3W max.

You need a fan dimmer or a variac, a 34V to 42V AC, 50VA transformer, a rectifier and a capacitor. The spec sheets talk about electronic commutation, so it's an AC motor, no brushes there. The EMI you'd get would come from the dimmer mainly, and would not produce enough EMI to cause problems.
 
Well, at 63dBA you sure are a brave one, I have 2 Deltas that top 50dBA and I can hear them clear across my house in my kitchen when they are at max. I would invest in some good ear plugs.

Though I like the idea, I had planed on building a custom case to look like a jet and was going to use some of the larger duct fans from the R/C world to get the right look, but just have not had the time.

Good luck with your noise machine.
 
I thought a little about it, the fan could be slowed down a lot with a PWM circuit. It probably wouldn't be too noisy, but might not be pushing hundreds of CFMs anymore :p
 
Thanks for the feedback, I knew this was the right place to find answers without anyone asking "what the hell for?" Frankly, because it lives in the basement, board temps run at about 36c already. I think the obvious answer is "because it would be pretty freaking cool" (pun intended).

Again, thanks.
 
jtoone said:
Thanks for the feedback, I knew this was the right place to find answers without anyone asking "what the hell for?"
Click to expand...


Hell yeah. This is the [H]ardForum....there is no asking "Why?" when it comes to pushing the limit. :D
 
I saw a whole bin at a surplus store full of some 50mm(roughly) thick 120mm Papst 24v fans and I was tempted to pick a few up, I was hoping to find some more 120mm 12v Papst Multifan 4312's for $5 but they didn't have any.
 
Well, the spec sheet I linked isn't the exact model I have. I finally peeled off all the price sticker to get to the specs printed on the fan itself (on the whole fan, they couldn't find another spot to put the price sticker?).

Anyhow, it's only a 16w motor, not 40. So that comes out to less than .35a. The brick I have is rated .4a, so I'm going to give it a shot. What's the worst, I'm out $5 and I have to open a window?
 
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