Magnetically held bearing fans

[Cathar]

Something which has been crossing my mind more and more in the hunt for quiet fans is the though of a magnetically suspended bearing shaft for a fan rotor.

I'm wondering if this sort of thing has been done before? I'm talking about the rotor bearing being suspended mechanically when the fan is turned off, but when the fan is turned on the bearing shaft gets centered and effectively just spins in mid-air. Would probably need some beefy magnets at either end to hundle any thrust that the fan would produce, but after looking at how powerful disk-drive magnets are, this sort of thing doesn't seem to me to be too far fetched to expect that it could be done - basically a friction free bearing on a fan axle - thereby reducing one of the major sources of fan noise - being the bearing itself.

Thoughts? Too expensive? Too crazy?

[tmod]

Sunon first introduced these in 1999, IIRC. The technology works, but thus far they offer no real advantages. You'd expect them to quieter, but they really aren't unfortunately.

[HammerSandwich]

Like this?

I got a KDE1207PHB1 about a year ago. It's a high-RPM screamer, but motor and bearing noise are quite good. Vibration is also low, though that may be partly because it is only a 70mm fan.

[HammerSandwich]

Man, that'll teach me to reread my posts.

[Cathar]

Thanks for the links guys.

[snowwie]

didn't swiftech ship their NB heatsinks with those fans?

[Dunno]

Hmm... Quiet fans.

Earth the rad.
Mount a piece of metal grill/gause about 1.5cm from the rad, parallel to it.
Put a positive, or negative, charge of around 30 000 volts on the grill.

What happens is you have an electron flow from the grill to the rad. These electrons travel veeeery fast! They then drag the surrounding air with them creating enough flow to make certain experiments hover! (do a search for 'high voltage')

You should be able to use old monitors to get the voltage, but may need 2 or 3 to get enough amerage.

There you go: A dead quiet fan without any moving parts!

(It seems that if you have have a negative charge on the grill you may get an extra cooling effect in that the heat exited electrons are removed from the rad and replaced with calmer ones. Cant find the link to this info though any-more. :shrug: )

[Cathar]

Hmmm, 30000V attached to the rad - no thanks.

Perhaps this may be a better solution in the same vein?

http://nanotechwire.com/news.asp?nid=828&ntid=117&pg=1

Wonder what they're like to keep clean and unclogged though in regular air. Would basic regular air-pollution just clog them up over time?

[killernoodle]

Isnt that kinda like what is on thos "ionic breeze" commercials that claims it accelerates air into the room without fans?http://www.seenontvmall.net/househol...onicbreeze.htm

[HammerSandwich]

Ooh, ooh! It could work as an electrostatic speaker too!

[Dunno]

He He! nice response! I was expecting "Your Nuts! Go away!" but it seems we have some broad minded people here.

Cathar

Your rad is earthed. So no voltage diff between it and the case etc. And no chance of blowing anything even with a dead short. A dead short should have other interesting effects though! The Potential Difference lies between the grill and earth/rad.

Favd your link. THX Cathar.

This is out there:
The grill should be - 30 000V to pull heat excited electrons out of the Rad for an extra, obscure, cooling effect... Or is it the other way round??? - Wish I could find that link to a patent...

I wish someone would try this; If the effect has enough juice to levitate things it should work well. Especially when combined with convection.

[Dunno]

Found the link to the 'out there' patent.

Basically what the are saying is because you have electrons bombarding the rad surface you break up the boundry layer which dramaticaly improves cooling.

There may also be an, as yet, un-understood cooling effect in that heat excited electrons are replaced with calmer ones?

A more scientific Lifter link.

Try this someone!

(A plastic case can be made to house this so that you dont electrocute your children or cat. Your monitor contains 30 000 volts. alternativly an Exos or similar could be modded)

[KnightElite]

Some guys at my college built a lifter for an engineering fair, and it worked fine, so it definitely does work.

[BillA]

this Blomgren is an interesting fellow
got a little too close to the flame it seems

[Incoherent]

Originally Posted by Dunno

He He! nice response!
This is out there:
The grill should be - 30 000V to pull heat excited electrons out of the Rad for an extra, obscure, cooling effect... Or is it the other way round??? - Wish I could find that link to a patent...

It is the other way round.
I really like this idea.
You will find that you want a positive charge on the anode, in this case the grill. The negative cathode (radiator) is the thing emitting electrons.
Remember, current flows from negative to positive in reality, the conventional current (+ve to -ve) idea is just too ingrained to be dislodged from collective consciousness.

[Dunno]

Originally Posted by Incoherent

It is the other way round.
I really like this idea.
You will find that you want a positive charge on the anode, in this case the grill. The negative cathode (radiator) is the thing emitting electrons.
Remember, current flows from negative to positive in reality, the conventional current (+ve to -ve) idea is just too ingrained to be dislodged from collective consciousness.

THX

You'r right; Blomgren makes a vague reference to a 'heating effect if the other way round???

Originally Posted by unregistered

this Blomgren is an interesting fellow
got a little too close to the flame it seems

There are a lot of great patents out there that have been suppressed, I think.

I'm starting to wish I'd bought an Exos instead of the Complete Koolance case.
I do have a home made rad enclosure riveted to the bottem of my old PC...

(Grabs old PC and Monitor and dashes into workshop to discover its the middle of the night!)

Its going to be cool to have a really efficient rad working on nothing but a bit of 'static electricity' and nice ionized air to boot!

[DrMemory]

A few words for the need for extreme caution are in order. A very high voltage source (10's of KV) producing even small amounts of current, 10's to 100's of uA can be DEADLY. This is way more voltage and current than is needed to start a heart fibulating. A cutoff switch to turn off the high voltage if the case is opened should be used. After the high voltage is turned off, some method of insuring that the high voltage is bled off should be used.

Also the high voltage power supplies in TV's produce positive voltages. This voltage is used to charge the anode at the screen end of the tube. It is used to accelerate the electrons emitted by the cathode (electron gun) at the end of the tube neck toward the screen. Reversing the current flow through the primary winding of the flyback transformer should do the trick, but the drive circuit (power transistor and its control voltage) will have to be changed to do so.

[DrMemory]

Another thought on using high voltage power in a PC:

The case of all PCs (except plastic ones of course) is connected to the AC earth ground through the power supply. Earth ground is connected to the power supply output voltage(s) ground in the power supply. This would make it extremely difficult to get the electrons to go where you wanted them to, although it might produce a really cool and unique "lighted" PC case. The downside is that it would almost certainly kill the motherboard.

[Incoherent]

Originally Posted by DrMemory

Another thought on using high voltage power in a PC:

The case of all PCs (except plastic ones of course) is connected to the AC earth ground through the power supply. Earth ground is connected to the power supply output voltage(s) ground in the power supply. This would make it extremely difficult to get the electrons to go where you wanted them to, although it might produce a really cool and unique "lighted" PC case. The downside is that it would almost certainly kill the motherboard.

I think you'd want an external unit. Like a fly zapper kind of deal. Anyone know what kind of voltages those are producing?

[Dunno]

Originally Posted by DrMemory

A few words for the need for extreme caution are in order. A very high voltage source (10's of KV) producing even small amounts of current, 10's to 100's of uA can be DEADLY. This is way more voltage and current than is needed to start a heart fibulating. A cutoff switch to turn off the high voltage if the case is opened should be used. After the high voltage is turned off, some method of insuring that the high voltage is bled off should be used.

Im no expert but I thought that the heart fribulation thing had to do with the frequency AC power being similar to the nervous system's impulses to the heart?
Isn't that why America use 110V @ 60Hz while most other places use 220V @ 50Hz?

Agree about bleeding of the high voltage. Seems that a 10Kohm resistor is used. Still don't want to be shocked!

Originally Posted by DrMemory

Reversing the current flow through the primary winding of the flyback transformer should do the trick, but the drive circuit (power transistor and its control voltage) will have to be changed to do so.

THX!
As the rad would be earthed it seems, after some research, that it does not matter wether the screen is + or -:
If positive, the positivly charged air will rush towards the rad. (closest thing) Draging neutral air molicules along with them. Negative air for a neg screen.
Speed is 28 800 Km/h for the ions!!

I would like to be able to switch the screen from + to - to check for the 'other' cooling effect.

Originally Posted by DrMemory

...would make it extremely difficult to get the electrons to go where you wanted them to, although it might produce a really cool and unique "lighted" PC case. The downside is that it would almost certainly kill the motherboard.

Nope:
Electricity, like heat, always takes the shortest path. So as long as the rad is the closest thing to the screen and electrical connections... thats where it, via ionised air, will go.
I would definatly prefer to use a plastic case though just to make sure that they all head in the right direction.
Yes there will some corona lighting though, so yeah! Cool lighting effects as a bonus!
Though I think it may be safe to install this inside a case I would definatly go external like Incoherent says. Just in case! Er... out case?

Originally Posted by Incoherent

I think you'd want an external unit. Like a fly zapper kind of deal. Anyone know what kind of voltages those are producing?

Hmm... Fly Zapper... good thinking there Incoherent! may be the perfect power supply!?

Also from my research it seems that high voltage likes to escape from sharp points, via ions. So a grid with evenly spaced sharp points would probably be best. Or very thin wire threaded on a insulated 'jig' could work well. Wire 0.1 mm thick is best it seems.

Been researching and thinking how to build this with testing in mind.
Sadly my old WC rad. and fan etc. enclosure is steel.

Pic 1:

The bottem box is home made

Pic2:


Pic3:


Some links I found for research:
Link1
Link 2
Link 3
Link 4

Feel like I pirated Cathar's thread , sorry C, maybe this should be moved??

[Bigmack]

That setup will work real good as a dust collector. "Ionic Breeze" We have five units at work called "Smog Hogs" that use the very same principal to remove welding dust, machining oil smoke, and other contaminants from the air. They are very effective! (and dirty), (and a pain in the a$# to clean) Their operating voltage is 15 kv. The ioniser grid is negitive and the collector grid is positive. Both grids are insulated from ground.

Beware the dust bunny brigade!!!

[BillA]

ok
so reverse the voltage and repel the bunnies
zap 'em as they roll across a metal plate ?

[Bigmack]

Mmmmmmm,,,,, Crispy Dust Bunnies!!!

[Dunno]

Originally Posted by Bigmack

That setup will work real good as a dust collector. "Ionic Breeze" We have five units at work called "Smog Hogs" that use the very same principal to remove welding dust, machining oil smoke, and other contaminants from the air. They are very effective! (and dirty), (and a pain in the a$# to clean) Their operating voltage is 15 kv. The ioniser grid is negitive and the collector grid is positive. Both grids are insulated from ground.

Beware the dust bunny brigade!!!

Hmm... Well air ionizers have long been used as air purifiers for rooms. They work by ionizing the air in the room with a slight negative charge. This causes the air to repel smoke, dust, and even bacteria that normally floats about in it, and causes such to fall to the ground I think. So it makes sence that all sorts of gumf would stick to the + pole. A good filter would be required.

Another thing to be carefull of is producing O-zone or O3. While its good in the upper atmosphere it is highly..erm... oxidative? It oxidises anything it comes in contact with including the cells in your body/lungs so can be a serious irritant.
I am still looking into this: Ionized air is good clean and invigorating, like after a thunder storm. Take it too far though and you start to get too much O-zone....

[DrMemory]

No, high voltage DC can do the same thing. All it takes is a large enough voltage along with the resistance of a human body to produce 10 to 100 uA of current across the heart. Penetrating the skin greatly reduces the resistance. Anything greater than about 40V DC can be dangerous!

TV high voltage power supplies produce a DC voltage. Actually the flyback transformer produces high voltage AC much like a switching power supply, but it is rectified to DC.

In order to have the electrons flow with the radiator GROUNDED, you will have to produce
a negative voltage (electrons). Otherwise you will produce current flow (and voltage) in the ground path and trip ground fault interrupters if you have them in your AC outlets, and confuse the crap out of the circuits (power supply, motherboards, etc.) that expect ground to be ground (~ 0V).

High voltage (actually any voltage) seeks the path of least resistance, not shortest distance.