Re: [LAD] Wireless Electricity vs audio quality

Dan Mills wrote:
> On Tue, 2008-08-26 at 13:07 +0700, Patrick Shirkey wrote:
>
>
>> They demo'd a 60w light bulb which they said could get 80% efficiency
>> upto 3 feet. They are expecting to increase the distance as the RnD
>> progresses. You can expect the transfer efficiency and power rating to
>> increase with time too.
>>
>
> They demoed a 60W lightbulb in a laboratory environment, there are lots
> of things you can do under those conditions that just plain don't fly in
> the real world.
>
> In a sufficiently well screened room with RF reflective surfaces, many
> things are possible.
>
>
>

I don't see how there was any room for the reflective surfaces in the
hall to have an impact on the amount of energy received by the bulb.
There was only three feet separating the transmit/recieve points.

>> The guy at MIT who designed the circuit has been on record saying it
>> will not interfere because the coupling is done at a very specific
>> frequency.
>>
>
> That don't help when there are non linear junctions in the area....
>
> I call him at best semi competent at either analogue design or design
> for emc. Further the occupational limits for non ionising radiation
> would (at least in Europe) surely kill this thing.

Everyone has cellphones even though the health hazards are still largely
unknown. Cigarettes are still legally available too. I don't see why
they will stop this technology from coming to market if it has the
support of the industry behind it. This particular circuit was first
made public about 18 months ago and now that Intel are actively pursuing
it I don't think it will be long before Sony, Samsung, Toshiba,
Phillips, Apple et al get behind it too. After all Apple get a lot of
their new technology from these guys and are using Intel in all their
latest PC/notebook lines.

> I could also see
> serious issues with induction heating of any highly conductive materials
> bought into the field, it don't need to be resonant for eddy currents to
> heat it.
>
>
I'm agree that this is a serious concern that needs to be addressed but
from what I have read they are pretty specific about it not being a
problem. This may be along the same lines as the Large Hydron collider
creating a black hole to consume the solar system.

>>> It
>>> will never work well over any distance as the inverse square law applies
>>> once you are out of the near field of the aerial (A tuned loop from what
>>> I can see - also very old technology), this distance depends on both
>>> wavelength and loop dimensions, so making the loop smaller will not
>>> improve things).
>>>
>>
>> I believe Tesla would have had a word to say about the above statement...
>>
>
> Well, if you want to play appeal to irrelevant authorities, then Maxwell
> would I think agree with my position.....
>
>
Sure and Edison would probably too.

> The thing is a cool demo of an air core resonant transformer with a
> somewhat high leakage inductance, (and I suspect an automatic matching
> and tuning network) but IMHO that is all it is.
>
> That demo had the look of the canonical 'trade show demo' to me (don't
> look behind the curtain). I don't really see much to get excited about
> here and there does not to me seem to be anything really new.
>
>

I certainly agree that they had most likely adjusted the environmental
conditions to there favor for the demo but from where I stand if/when
this tech becomes available for the industry we will definitely be
incorporating it into our products.

-- 
Patrick Shirkey
Boost Hardware Ltd.
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