NEWS: Physics promises wireless power

SMS hath wroth:

Ouch. At that high a charge rate, the charger would need to deliver at least double the laptop current drain. So much for my theory. Never mind.

It can be either. It used to be AC but quite some time ago they developed efficient solid state methods to do the conversion. A number of utilities have high voltage DC transmission lines in service. My buddy works for one of them and they put one of the originals in service at least 25 years ago.

Toshiba has Li-Ion batteries coming that can be fully charged in 10 minutes. The company claims that they will be out in 2008.

On Thu, 16 Nov 2006 06:51:52 -0800, SMS wrote in :

[yawn] We've had 15 minute NiMH recharging for quite some time.

They ALWAYS find out that they didn't account for something after millions of people have been exposed. Considering the amount of energy in question here is significant when considering long term exposure, I don't think it can be so easily dismissed. Consider the fact that animal life has never in history been so exposed to radiation as the modern human has. Adding more energy to the mix is potentially more destructive so the frequency must be chosen wisely and tested carefully.

We had this discussion before. Some of it is.

Many supply enough power to power the laptop, with periphs AND charge the battery. So, the power supply should significantly exceed the normal power consumption.

On Thu, 16 Nov 2006 16:41:29 GMT, "Thomas T. Veldhouse" wrote in :

Not always. People have been ranting about RF harm for years without any real justification.

I respectfully suggest you read (and understand) the paper before leaping to conclusions.

Or run Half-Life II. ;-)

On Thu, 16 Nov 2006 16:41:55 GMT, "Thomas T. Veldhouse" wrote in :

Steven doesn't let facts get in the way of stuff he makes up. ;)

Yes, and it significantly decreases the life of the battery ... they simply get too hot!

Sheesh ... where did you come from? I am not so sure John said anything wrong here.

On Thu, 16 Nov 2006 16:47:32 GMT, "Thomas T. Veldhouse" wrote in :

I got some of the first IC3 units on the market, and they are still performing superbly, at least as well as conventional NiMH cells.

Temperature actually stays within the safe range for these IC3 NiMH cells, due to self-monitoring in each cell.

AA NiMH batteries are cheap enough that you can replace them and still make it worth it if the life is shortened. I am not sure the scale of the damage, but it is considered significant. If you go to Thomas Distributing,

you will find many chargers available that are built explicity to avoid this affect. I use one, the Maha C401FS, which offers the ability to recondition old batteries, slow and fast charge (not 15 minutes though) and it does a very good job with getting the most out of my power cells.

Yes, they made the batteries safe, but they still allow the heat to get high enough to reduce the life of the battery. It is a tradeoff between minimizing the charge time or maximizing the usable cell life.

How long have Cell Phones been in COMMON use? 15 years maximum? That is hardly a significant duration. I still wonder what diseases our kids might be getting after 50 years near constant cellular use. You think cancer is rampant now ...

I understand it is a tesla coil and that they can pick the frequency of resonance. There is nothing special about that. Since there IS power being transmitted as radiation and since it is in a specific frequency band, it had better be tested thoroughly as safe, because its adoption will be widespread if it works. We all know that the more energetic the radiation exposure is, the more potential damage. I have watched many people die of cancer, not the least of which was my Father ... and I do NOT want another environmental risk added in the name of consumption.

On Thu, 16 Nov 2006 16:58:46 GMT, "Thomas T. Veldhouse" wrote in :

By whom? What actual evidence of damage to IC3 cells?

There's some good stuff on that website, but there's some baloney as well; e.g., reconditioning, which is a hangover from old NiCd designs that doesn't even apply to modern NiCd designs, much less NiMH or LiIon.

FWIW, I have a MAHA charger, but it's old technology compared to IC3.

Have you actually measured the temperature? I have, which is how I know it stays within the recommended limit for NiMH cells.

"Thomas T. Veldhouse" hath wroth:

Bad assumption. I've done some experiments in very fast charging NiCd batteries at rates up to about 200 times the rated current to see what happens (Learn By Destroying). The battery does not get warm until overcharged. The trick is to determine when to stop charging. I think I scribbled something on my tinkering in the past.... |

far as I can determine, I've seen no accelerated ageing problems with such fast charging as long as I don't go over about 95% of full charge. Those where I have exceeded full charge and have started heating have died prematurely (or exploded). My guess is that the only reason this is not being done in production units is the safety issue. One mistake in such a fast charger and we have an explosion of attorneys.

John Navas hath wroth:

Sorry, I was late for lunch and didn't even bother to look. Thanks for the link.

Well, yes. That's exactly what I did. I've done far more spectacular jobs of shoving my foot in my mouth in the past, so I'm used to the experience. Occasionally, I'm even right. What I posted is accurate for a simple RF resonant transformer which is what I assumed was under discussion. Apparently not.

Yep. Again, thanks for the link. I've read the 17 page article several times and understand very little of it. I'm not a theoretical physicist and the terminology, buzzwords, and notation is way over my rapidly balding head. What I have been able to determine is that it only works with: "long-lifetime resonant electromagnetic states with localized slowly-evanescent field patterns" of which I've able to find very little. I found some research on non-radiating objects in nano research under quantum dots, where emissions from a quantum well does not propagate in the same manner as conventional electromagnetic radiation.

The paper assumes that such a non-radiative phenomenon exists, speculates as to how it might work for transferring energy, and how human body interference might cause problems. This is quite proper as the authors are all involved in the Center for Materials Science and Engineering and Research Laboratory of Electronics at MIT.

Two examples are given. The "whispering gallery" construct, which are two parabolic dish reflectors separated by a high dielectric material disk. The other is a conventional resonant symmetrical RF transformer composed of this non-radiative class of material.

The question of how one is to conjure such a non-radiative material with long-lived resonances is not explored. I consider this to be a rather fundamental problem thus making the immediate exploitation of the theory into practical products a rather dubious proposition. The supplied references to the technology (2,3,4, and 5) all refer to conventional transformer action or RF power transmission, with no mention of any exotic non-radiative material. As far as I can determine, none of the other references offer anything better. (Translation: The stuff doesn't exist yet).

Unless I missed something (a real possibility), the lack of any references as to the nature of this non-radiative and long-lifetime resonant (high Q) material suggests that the trade press may have misinterpreted the purpose of the paper. It appears to be calculations involving the feasibility of using such a material for power transmission should such a material be found. In other words, it's the traditional "more research is necessary" sales pitch for funding research into finding such a material. Whether this can be accomplished is subject to additional debate.

On Thu, 16 Nov 2006 09:14:10 -0800, Jeff Liebermann wrote in :

NiCd experience doesn't directly apply to NiMH, since NiCd is sufficiently different from NiMH that different fast charging techniques must be used. That's primarily because charging of:

• NiCd is endothermic (absorbs heat) until the point of overcharge

• NiMH is exothermic (gives off heat)

Thus NiMH gives off more heat than NiCd, especially during fast charge.

True, and the sudden rise in temperature of NiCd when they go into overcharge is a common means of charge termination. NiMH is sufficiently different that more subtle means of charge termination are normally employed.

As far as I can determine, I've seen no accelerated ageing problems

NiMH batteries will readily tolerate operating temperatures of 55° C (130° F), with safe charging up to cutoff at 75° C (167° F). This is of course quite hot to the touch, which leads some people to think the temperature is excessive.

The primary issue with NiMH fast charge is overpressure and venting, which results in damage to the cell.

For more info, see