Posted on 11/18/2011 6:41:52 AM PST by Titus-Maximus
SALT LAKE CITY -- A radically new way of moving people around on the University of Utah campus is about to become a reality, thanks to 2.7 million dollars in start-up funds from the federal government.
A new transit route through the heart of the campus will feature a full-size city bus, operated with an electric motor. But it will never need to be plugged in. Instead, it will get its energy wirelessly thanks to a magnetic field emanating from the pavement.
If it works, it's a significant step toward the so-called "Highway of the Future," a concept in which electric vehicles could draw their energy from the pavement, without ever stopping to recharge. The electric bus approach is much more modest, relying on a single magnetic pad buried under asphalt. But it's already stirring national interest among transit experts.
The concept relies on breakthrough technology developed at Utah State University in Logan. The bus will be equipped with its electric charging system by WAVE, Inc. a Utah State University spin-off company.
"If it works well on the University of Utah campus," said WAVE CEO Wesley Smith, "our model will be to duplicate that to transit agencies around the country as well as campuses around the country." If the technology ever returns a profit, USU would share in the revenue.
one wonders about the effect this magnetic field would have on the health of people particularly the aged, the infirm, and the infants...
Ping.
Ping.
A couple of comments on your post(a) 18 and 19.
First I have no idea if this scheme is viable... That said, there is a big difference between magnetic coupling which is what is being proposed, and electromagnetic waves. The former does not propagate energy, the later does.
What they are proposing is basically a transformer with the primary being in the pavement and the secondary being on the buss. Transformers can be designed to be very efficient. Well over 95%. This design would be very problematic, but I wouldn’t go so far as to say it couldn’t be done.
As far as the energy costs go, it wouldn’t be any more than conventional electrical propulsion, and it would probably be a bit less.
Just wait. A bunch of ¨students¨ will claim the thing is frying their brains, then turn around and sue the feds. So the taxpayer gets screwed coming and going.
Only if they do it in three’s while nursing pigeons back to health.................
I stand by my statement that this will be cost prohibitive if large numbers of vehicles are charged this way.
One (or more) of those gay guys wearing a metal ring around his/her/it's nether parts is in for a shock (no pun intended)....and a couple of little balls drop off.
(It's the induced electronagnetic field effect....causes heating.....for those in Rio Vista)
One enterprising homeless even rents out a set of coils and connectors.....
It was reported that some of the coils were stolen by other homeless for recycling....as local liquor stores swap copper for booze.
Frankly if it saves a buck, I see the Chinese doing this as they make their country a vast bumper car arena.
They have yet to build roads, and they are building 25 nukes. Build 100 more. It may make a lot more sense than buying oil.
“I do know the difference between magnetic coupling and electro/magnetic waves although there is very little difference and they both use the same principle to function, the transfer of electricity by electro/magnetic waves.”
Sorry calex59, this is absolutely wrong. Electromagnet waves have an electric and a magnetic component, while a transformer uses magnetic only. They are not the same thing.
As an example, if you apply an ac voltage to a wire, a magnetic field will be generated around the wire. When you reverse the voltage on the wire the field collapses and the energy goes back into the wire. It’s referred to as back emf. This is inductive coupling.
On the other hand, electromagnet waves propagate from a wire and the energy is gone from the circuit.
Another example would be a inductive cook top on a stove. You turn on the top and it draws very little current until you put a conductive pot on it.
Mr Smith unfortunetly parked his SUV over one of the magnetically coupled grid lines....the field melted then ignited his tires (through the steel belting) and unexpectedly caused the SUV to incinerate.....
You need to readjust your sarc detector.
Irony at it's max.
The green crowd will hail this as some sort of breakthrough. I bet it isn't green at all. The efficiency must be terrible compared to hard wired charging circuits.
Answer is no, as far as a magnetic field is concerned lead looks like air and does not alter the field. There is a material used to shield magnetic fields, its called Mu (pronounced 'meow', like a cat call) metal. It is notable for its high magnetic permeability. The high permeability makes mu-metal very effective at screening static or low-frequency magnetic fields. Another high permeability alloy is permalloy which has similar magnetic properties.
Before we go all nutso on shielding I should point out that the human body is subject to the earth's magnetic field every day and to much stronger fields when having a MRI scan. There are no side effects to such exposure unless of course you have a prosthesis made of hardenable stainless steel, then you might feel a sudden attraction!
Shielding the field defeats the purpose of generating it in the first place. The whole idea is to construct what amounts to a transformer with the primary coil buried under the pavement and the secondary under the bus. Whenever the bus stops over the primary the magnetic flux couples to the secondary and induces an electric current to charge the bus batteries. If someone put a coil under his Prius and tried to grab some free juice, he would have to park in a bus loading zone. It would seem wasteful to leave the primary energized whenever there was no bus present for charging and I would think that designers would include a "below the pavement sensor" (like they use for left turn sensing) to switch off the primary when no authorized vehicle was present.
The biggest problem I can see is that nearly all transformers are constructed around iron cores which have a permeability of several thousand compared to air which has a permeability of one. Permeability is a measure of a materials ability to support a magnetic field, it would be analogous to conductivity (1/r) in an electric circuit. If you put an iron core in both the primary and secondary coils the problem remains because the two cores are separated by two air gaps. Perhaps the best you could do would be to bring the primary core (pole pieces) as near to the surface as possible and design the secondary to lower itself into contact when properly aligned. This precludes charging on the go but that would be a tremendous waste of energy in any event.
It seems that a much simpler solution would be trolly buses (rubber tired vehicles) with an overhead trolly system to supply continuous power to series wound traction motors.
Regards,
GtG
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