Re: Any alternatives for conventional gasoline?

On Wed, 28 Jun 2006 08:48:24 -0700, Don Lancaster <don@xxxxxxxxxx>
wrote:

Josh Hill wrote:
On Mon, 12 Jun 2006 15:38:48 +0100, Pooh Bear
<rabbitsfriendsandrelations@xxxxxxxxxxx> wrote:

The coils needn't be positioned in free air -- they can be wound on
cores.

Inductive charging paddles are already used on some battery-powered
vehicles. Here's a brief writeup of a proposal to charge electric
vehicles with coils under a driveway:

http://home.earthlink.net/~bdewey/EV_chargedebate.html

The proposals I've seen for inductive roadways posit a guidance system
that keeps the car centered in its lane (not sure how they handle snow
. . . ) I found a brief discussion here:

http://home.earthlink.net/~fradella/car.htm

Seems the DOT/DOE studied them, but I wasn't able to find the study
online, or much information of any kind -- most of the search results
I get are about induction motors.

And here's a (completely obvious, but what else is new) patent:

http://www.freepatentsonline.com/5311973.pdf


No way.

Any airgap spacing between cores of more than a few tens of mils utterly
trashes the transferrable power.

Those induction charging paddles involve very small airgaps. Perhaps
five mils. There is DIRECT PHYSICAL CONTACT between the paddle and the
paddle receiver. Iron paths are seperated ONLY by the thinest of
reasonable insulating dielectrics.

Ridiculously smaller than is even remotely possible on an air tired
vehicle on a highway.

Induction highways are laughingly and ludicrously absurd both on cost
and on engineering fundamentals.

On cost, perhaps, although the coils would need to be present on only
part of the route & I'd want to see some real figures before reaching
a conclusion.

There are ways to minimize the air gap and its effect, e.g.,
positioning the secondary with voice coils and using large pole
pieces. Hell, as a conceptual limit, you could arrange for direct
mechanical contact with the surface material, as in a third rail or
catenary system. OTOH, I'd be concerned with practical engineering
issues such as road buckling, debris, ice, and snow. Forex, how would
a 1 m^2 pickup work on a street with a constantly changing grade?

But again, the big issues seem to me cost, particularly the
chicken-and-egg cost of the road infrastructure, which would have to
achieve wide coverage but would initially serve only a few vehicles;
competitiveness, since the price of batteries and fuel cells will
continue to decrease and might set an effective upper limit on the
service life of the infrastructure; and practicality, e.g. the
practical difficulty of eliminating gaps in coverage.

Induction might be more practical as a means to power municipal
trolley buses without overhead wires: as one patent points out, buses
have an advantage in that the coils need be placed only at bus stops
and other places where the buses idle and the air gap can be virtually
eliminated because charging occurs when the bus is stationary.

--
Josh

"I love it when I'm around the country club, and I hear people talking about the debilitating
effects of a welfare society. At the same time, they leave their kids a lifetime and beyond
of food stamps. Instead of having a welfare officer, they have a trust officer. And instead
of food stamps, they have stocks and bonds."

- Warren Buffett
.

Relevant Pages

  • Re: Any alternatives for conventional gasoline?
    ... Inductive charging paddles are already used on some battery-powered ... vehicles with coils under a driveway: ... Those induction charging paddles involve very small airgaps. ... and practicality, ...
    (sci.energy.hydrogen)
  • Re: Any alternatives for conventional gasoline?
    ... by induction has been available for years. ... battery. ... The coils needn't be positioned in free air -- they can be wound on ... Inductive charging paddles are already used on some battery-powered ...
    (sci.energy.hydrogen)
  • Re: Any alternatives for conventional gasoline?
    ... You apparently haven't twigged that no 'useful power' can be supplied through anything more than ... Irrelevant to road vehicles. ... Needless to say, there are practical obstacles to an induction system, ... the theory and the engineering knowledge necessary ...
    (sci.energy.hydrogen)
  • Re: Any alternatives for conventional gasoline?
    ... understanding of physics/ / electricity. ... by induction has been available for years. ... I read the previous post as referring to 'induction coils' to recharge the ... Instead of having a welfare officer, ...
    (sci.energy.hydrogen)
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