backtop


Print 68 comment(s) - last by oTAL.. on Jan 8 at 10:11 AM


Kronos cooling run at 8.5kilo-volts to cool a device 25 degrees Celsius - Image courtesy TheFutureofThings.com
Kronos Advanced Technologies claims that's the way we're headed

Lately, heatsinks and traditional fans have become so large that they are beginning to be obstructive and are sometimes too heavy. This is an issue on the graphics processor front in many ways, as there isn't enough room for large heatsinks, yet GPU thermal exceeds that of high-speed CPUs.

A company called Kronos Advanced Technologies is working on a method of removing heat from devices such as CPUs by using ionic discharge to create a fluid motion of air. This technology has been around for a few years and is used in products such as ionic air filters, which have no moving parts but still move volumes of air and create quite a strong breeze. The same concept is being applied to micro processor cooling.

Despite the advancement however, the volume of air moved over the CPU core is still small because the core surface area is small. Heatsinks are used to increase surface area of the hot surface, so that when air is moved over the fins, more heat can transfer to the air. The Kronos' device will attempt to remove hot air away from the processor core directly without the need for heatsinks. With this method, the velocity of air being moved needs to be extremely fast in order to compensate for the lack of surface area -- and speed is something that ionic air "movers" lack.

Right now, Kronos is still working on prototypes, which it claims are scalable from very small micro coolers to large scale sizes. Power requirements also appear to be quite steep at this point in time. One of Kronos' demonstration shows a heated area being reduced from roughly 50C to 25C using an ionic cooler, but the power supply required around 8.5kV, or 8500 volts, to stay stable.


Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: 2.5kV?
By Griswold on 1/4/2007 6:29:28 PM , Rating: 1
Oops, there is a typo. Can you find it (order of magnitude)?


RE: 2.5kV?
By ChronoReverse on 1/4/2007 6:39:12 PM , Rating: 2
100 000 Volts / 1000 Ohms = 100Amps

However, generally the dry skin resistance is WAY higher than that. In the range of a mega ohm.


RE: 2.5kV?
By Griswold on 1/4/2007 6:46:12 PM , Rating: 1
In theory it is 4MOhm, but as soon as a current starts to flow beneath the skin (and it will flow, especially at that voltage) the average body resistance is 1kOhm and therefore it is commonly used. Besides that, skin is almost never dry.

The example is valid.


RE: 2.5kV?
By ChronoReverse on 1/4/2007 7:11:58 PM , Rating: 2
Even so, it depends a lot on where the current is going through.

For example, high frequency AC would tend to flow over the skin. At the same time even low currents going straight through the heart will cause severe problems. Even more strange is that a bit higher (but not too much), the heart would simply stop and then restart. So it's still not a very useful example in itself.


RE: 2.5kV?
By Griswold on 1/5/2007 3:19:10 AM , Rating: 1
The 100kV example is perfectly valid because it will kill you if you're in contact with it for more than a few seconds - if you're in contact with ground potential. Of course, HV sources such as these usually have safeguards (to protect the installation, not humans) that limit the current and shut down the installation if necessary. But that is not the point here.

However, I agree with you that for low currents, its a matter of where the current is passing through. 50mA can be enough to kill a human if it is passing through the heart - and that is a fact.

At any rate, the point is, electricity is not something to joke around with and you simply do not touch conductors upwards 50V without proper safety meassures. And its grossly negligent to tell laymen something else.


RE: 2.5kV?
By masher2 (blog) on 1/5/2007 7:10:15 AM , Rating: 3
> "50mA can be enough to kill a human if it is passing through the heart..."

Even less can be fatal over an extended period of time...paralysis of the chest muscles can occur with under 20 mA. The fact remains that, as I originally said, high voltage is, in of itself , not inherently dangerous. The source has to be able to supply enough current at that voltage level to be dangerous. Ohm's Law as you orginally used it assumes an idealized voltage source of zero internal impededance, capable of supplying infinite current-- something that doesn't exist in the real world. Its a concept useful for modelling...but only so long as your load resistance remains high enough for the abstraction to remain valid.

I don't know how I can explain this any simpler. If you don't want to believe me, there are countless online references to verify against.


RE: 2.5kV?
By eetnoyer on 1/5/2007 8:40:52 AM , Rating: 2
From my own experience in high school physics. We built a tesla coil with an approximate calculated voltage of 65-75kV and noone suffered any harm from the 1" or so sparks. Unless, of course, you count the guy that was standing a little to close to the island bench and arced to the outlet from his zipper.

Not an EE, just a chemist, but have a rough understanding of the subject.


RE: 2.5kV?
By oTAL on 1/8/2007 10:11:13 AM , Rating: 2
quote:
Unless, of course, you count the guy that was standing a little to close to the island bench and arced to the outlet from his zipper.


Now he can please the ladies many times a night (batteries sold separately).


RE: 2.5kV?
By NaughtyGeek on 1/4/2007 6:45:13 PM , Rating: 2
100000 Volts/1000 Ohms = 100 Amps


RE: 2.5kV?
By DangerIsGo on 1/4/2007 9:24:59 PM , Rating: 2
quote:
ground potential - and that is most likely what you were when you touched that conductor (I assume it was one of those demonstration thingies that make your hair stand up and the like).

There is a reason why 50V (AC @50Hz) is considered the safety threshold for humans. For DC, it is 120V.


Dont you mean positive +?

And isnt it AC = 120V and DC = 50V?


RE: 2.5kV?
By Griswold on 1/5/07, Rating: 0
RE: 2.5kV?
By masher2 (blog) on 1/5/2007 6:26:54 AM , Rating: 4
> "Thus, to get away from such demonstration without burn marks, you need to stand on a insulated platform, while touching the high voltage potential."

No and no. You're probably thinking of a Tesla coil demonstration, which generates not only an extremely high voltage, but a sizeable current as well. However, there are plenty of high voltage sources which are safe, grounded or not, such as a Van der Graaf generator. Even simple static electricty sparks can go to 10kV or more....ever seen anyone die from them?




"I want people to see my movies in the best formats possible. For [Paramount] to deny people who have Blu-ray sucks!" -- Movie Director Michael Bay

Related Articles













botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki