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Canadian Researchers Create Wireless Charger For Electric Cars
An anonymous reader writes "University of British Columbia researchers have developed a wireless charging system for electric cars. It involves a spinning magnet beneath the parked vehicle which turns another magnet in the underside of the car. Charging takes four hours and is about 90% as efficient as plugging in. From the article: '"One of the major challenges of electric vehicles is the need to connect cords and sockets in often cramped conditions and in bad weather," says David Woodson, managing director of UBC Building Operations.
"Since we began testing the system, the feedback from drivers has been overwhelmingly positive."
Four wireless charging stations have been installed at UBC's building operations parking lot. Tests show the system is more than 90 per cent efficient compared to a cable charge. A full charge takes four hours and enables the vehicle to run throughout an eight-hour shift.'"
OK, so it can double as a garage heater in winter. However, in the snowier parts of the country (i.e. NOT Vancouver and its suburbs), this will not be appreciated for outdoor use - lots of meltwater turning into smooth ice...
Those who can make you believe absurdities can make you commit atrocities. - Voltaire
I can only assume that this hopefully is a method that increases efficiency, but my first thought would be that if you have a magnet spinning nearby underneath a car, why not just put a coil in the car and generate electricity that way? Adding a second magnet just seems like it would add weight and mechanical complexity.
But if they went that route, I suppose they must've had good reason.
It doesn't but I can see how it would be easier to be efficient while doing so - you start trying to inductively couple things and you end up with magnetic field lines and EM flying all over the place. Not that it can't be done, but it's not trivial.
Whereas a pair of magnets under mutual attraction are basically locked together, and so all you're really dealing with is the mechanical efficiencies, and the second magnet can be the permanent stator of your generator.
Not if I'm paying for the electricity. I don't really feel like paying 10% extra to charge my car for the convenience of not having to plug it in. How much more does this charging system cost and how much does it add to my car's weight? Qualitatively, let's estimate that as "too much."
This will never work (for me!). Because people (just me!) use their cars continually, never stopping for long enough to get a charge. Everybody is a road nomad, a street shark...
And here I thought the whole point of going to an electric car was to become more efficient and green, wasting less power to random heat but now that it's been shown that people don't want to stand out in the rain, snow, overly hot weather, or in any place inconvenient, to plug in a charging cable (a task which most people would not be up to anyway unless it looked like an iPod earphone jack) we're going to give up some of that efficiency in the name of personal comfort.
Oh, the duplicity of it all.
It involves a spinning magnet beneath the parked vehicle which turns another magnet in the underside of the car.
Oh wow, it's a jumbo Magnetic Stir Plate! Perfect for that 1000L Erlenmeyer Flask in your garage.
I have visions of the recharge lane.
Not that I'm complaining... I'm just a bit surprised. News for nerds north of the 49th.... If this was November, I'd suspect some sort of alliteration joke to be forthcoming.
File under 'M' for 'Manic ranting'
OK now go get a snow saucer and tape a few strong magnets on some inside edges. go out to the parking lot. Put a quarter into the meter, sit, and spiiiiiin !
I work for the Department of Redundancy Department.
This is used all of the time in pumps where you don't want a dynamic seal. You have permanent magnets spun by a motor and inside a sealed case the pump is coupled by a magnetic field.
http://www.proconpumps.com/brands/Magnetically-Coupled-Pump-(Sealless).html
I love Jesus, except for his foreign policy.
And now that battery powered vehicles are becoming more main-stream, we can use oil when and where it's more useful (planes, trucking, remote power generating, etc.)
Straw man. It's no harder to close the magnetic circuit of an inductive charging system (electromagnets) than it is a pair of permanent magnets like this, if you know what you're doing. The only difference is this system will produce a much lower frequency electromagnetic oscillation--in fact, it would be easier for the inductive system, since higher frequencies require smaller and less sophisticated materials to contain. What is the radiative effect when the two spinning magnets are not centered perfectly, as compared to a non-centered inductive system?
Also, permanent magnets are expensive, and annoying. Try not to drop your credit card on the garage floor, even when it's turned off--and what is going to stick to the bottom of your car as you drive?
The only remaining question is: if there really is a power efficiency gain, is it not wholly negated by the added weight of this ridiculous, possibly unreliable mechanical contraption, compared to a standard induction charger?
Why not make it a two-part transformer? You'd just have a spinning magnetic field with no moving parts. You would also eliminate two extra rotary electrical machines (the motor in the charger and the generator in the car).
Ezekiel 23:20
Thank you, Nikola Tesla.
The mind conceives, the body achieves, the spirit manifests.
I knew if I waited long enough I would get my wind-up toys back. But why aren't they using a big spring?
Fortunately charging a car wouldn't need a 100kW microwave. Both because you don't need 100kW (unless you are in a hurry of charging your car, but then, I'm not sure the battery would take that anyway), and because you'd not use microwaves to do it (after all, you don't have to remote-charge your car; instead you'd put it directly onto the charger).
The Tao of math: The numbers you can count are not the real numbers.
Nope, us Canadians have nothing better to do on a Saturday other than post articles to Slashdot. Y'know, we have bitter cold and snowy winters, eh?
Brilliant. I'd make a teensy change. Replace the spinning magnet outside the car with a cable, and replace the spinning magnet and generator in the car's underbody with a plug. Run power through the cable to the plug, but only after there's been a handshake between the cable and the plug. Use the equipment that would spin the magnets to establish a physical connection between the cable and the plug.
I think the efficiency of this, compared to old techniques, will be closer to 100% of existing efficiency than to 90%.
why is the charger on when there is no car using it?
GENERATION 24: The first time you see this, copy it into your sig on any forum and add 1 to the generation. Social exper
Parking lots are normally plowed to be clear of snow. If the space was not plowed than how would the car park there to charge anyway? Your post does not make a lot of sense when you think about it.
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other benefits of computer driven cars - make money while at work by being a taxi
You are going to love it when it is returned to you at going-home time, and you find the floor swimming in some drunk's vomit, shit and condoms, discarded take-aways on the vandalised seats, and the navigator ripped out. Taxis get enough crap even with a driver present to moderate things.
I foresee losses due to eddy currents induced in the chassis of many cars. Because metal (usually steel) is the predominant chassis material currently and in the foreseeable future.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
...is more than paid for in the efficiency gained by not having to: train employees to plug their cars in;
Yes, it will require at least a week long course to learn how to put a plug in a socket - perhaps two weeks to be on the safe side.
.. actually have employees take the time to plug them in;
Yes, it must take at least 15 minutes to do that (who said anything about "employees" anyway?)
.. train the parking attendants to check the cars are plugged in,
Yes, that is going to need a degree in rocket science. (who said anything about "parking attendants" anyway?)
.. time lost to inclement weather for outdoor stations, ...
??????? The time to pluck up the courage to get out the car if it is raining? They will need to bite that bullet whether they have to plug a charger or not
a whole parking garage of wirelessly charging electric vehicles that _isn't_ a glowing electromagetic dome of inteference should be exciting.
I am sorry I was poking fun at you - now I realise you are poking fun yourself.
The magnetic fields are magically contained under the car? For that matter the moving magnetic fields won't overload every wire in the car?
If I was in BC I would drop a few pachinca balls into the bushes next to the prototypes. I'd love to see the experimenters shit themselves.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
I think I would go with the cable myself, you would also save a few thousand on car and wireless transmitter as well I imagine.
Troll is not a replacement for I disagree.
So does this mean that you would need to do a 100% perfect parking job to get the 90%, and if you were off by a few inches it would go way down, be off by a half a foot and it would not work at all?
It seems to me that parking the car perfectly would be significantly more work than just getting it within reach of a cable.
Troll is not a replacement for I disagree.
Parking lots are normally plowed to be clear of snow. If the space was not plowed than how would the car park there to charge anyway?
Just go to Ontario, or Maine, or Finland, or Sweden. There's lots of snow in winter, and parking lots (although plowed quite often) are rarely free of it. Cars drive on snow and can drive on quite a depth of packed snow or a few inches of unpacked snow. In fact, driving on snow is not at all difficult, especially with proper winter tires or even just with all-season radials, and nor is parking on snow.
Your post does not make a lot of sense when you think about it.
Actually, your response indicates that you have much to learn about driving in cold climates. Perhaps you should actually experience a colder climate, instead of just theorizing about it.
Those who can make you believe absurdities can make you commit atrocities. - Voltaire
Wireless power has been done before.
A more complicated solution involving inductive nearfield power was developed by GE for electric cars around 5 years ago, and they've demonstrated a near finished commercial product, asserted it was safe that would even work underwater, and wouldn't short.
Yes, there was a slashdot article, no I can't find it. They tried selling it to san franciso, but they opted out, as the unknown effects of high power RF.
On a serious note, doesn't a big rotating magnetic field have the risk of inducing currents in someones nervous or circulatory system?
That'd be more fun than a laser pointer!
If cars can be charged wirelessly, why couldn't there be a system in place such that cars recieve needed power from infrastructure along highways. Batteries as backup and "off-grid" travel only. Seems this could be TOTALLY doable now.
In fairness, TFA does not specify whether permanent or electromagnets are used in the device. I had assumed permanent magnets. But unless the car is actually using power to create an electromagnet that then spins to charge it (which I cannot imagine would make it 90% efficient), there will have to be a permanent magnet inside the car that will generate a constant magnetic field even when not charging / not at the charger.
It's called a "magnetic circuit" (scroll down halfway for an actual diagram). They are used all the time in high-efficiency motors and solenoids. By putting the right type of iron in the right shape around a coil or a permanent magnet, the iron provides a "path of least resistance" for the magnetic field lines and the field that escapes from the iron is small or miniscule.
If you have ever taken apart a mechanical hard drive, you will have found the very strong neodymium magnets used in the head travel motor are attached to a piece of metal--probably an alloy called "mu metal" or similar--and the observable effect is that you can only magnetically stick things to the magnet side, not the mu-metal side. That is because of where the magnetic field lines go: instead of going out one side of the magnet, around in the air, and back in the other side, they go out into the air on ones side and then directly into the mu metal, then through the mu metal and into the magnet. This not only shields the magnetic data on the hard drive platters from the motor magnets, but also greatly increases the efficiency of the motor.
I assume they will do the same thing with this car. There will be a pretty significant "air gap" in the magnetic circuit, which increases leakage, but it is easy to provide iron on the top side of the in-car magnet so that all the field lines are directed downward and away from the interior of the car.
How many pounds of pig iron did you just add to the weight of the car? It will still leak, alignment will be imperfect etc.
It's a dumb idea.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
This was the exact point that came to my mind.
The spinning magnet is going to need to maneuver into place anyway, why not just eschew the spinning part and once in it's aligned itself, plug in a port, thereby not losing that extra 10%.
You would need some pretty strong magnets, I would think. Strong magnetic fields can be very hazardous to people with pacemakers.
You mean like what they use for MRIs?
http://answers.yahoo.com/question/index?qid=20060902235859AAjZ7gx
http://www.rootstrikers.org/
IRRC the biggest unknown with these chargers is that it's effects on a small animal that chooses to sit right in the path of the inductance loop is largely unknown.
It's a bigger issue than you would think, since it does put out some heat, it is extremely likely that your family cat will find a new favorite sleeping place under the car.
Granted the biggest risk might be that of a 'squashing' incident when you park or drive off without first checking for your loved one; but the effects on living tissue of spending hours sitting on top of a giant electromagnet are not exactly known.
We know that running a 60 watt TV from across the room via inductance has zero effect on human health - but running 12.5kW through a cat is a slightly different equation.
The J1772 plug has five pins: Two for power, ground, pilot signal, and interlock. The interlock pin is wired to a bit of circuitry in the plug. The car checks for this circuit and won't come out of park if it is present.
Additionally, the pilot signal is what tells the car the amount of available amperage, since that's something the car cannot sense, like voltage. I won't bother to go through all of the details of the handshake, but this piece of information is provided by the duty cycle of the 1Khz square wave pilot signal, with 50% indicating 30A available. Not only does this let the car know what power is available so it won't try and draw too much, the amount of power can change over time (when there is, say, a power shortage) and the car responds accordingly.
The plug is also designed so that the signal pins disengage before the power pins, so both ends can sense the impending disconnect and stop the flow of power, preventing arcing.
The plug is also designed to be safe to use in wet conditions. There's also a ground fault detector.
With the exception of the ground fault, which I haven't tried to test for obvious reasons, I can attest to the fact that all of this works flawlessly on the Leaf. The situation with the Tesla Model S is more complex since there's an adapter involved and I haven't been willing to play with it to see what happens, but if anything it should be harder to move the Tesla in park since the emergency break engages automatically.
EVs used to be a big hacked up mess but that time is long since past.
This is a problem with the pacemakers, not the magnets, because it's a "feature" built into the pacemakers by design--see here: http://www.openanesthesia.org/index.php?title=Pacemakers/AICDs#Magnets
"Politicians and diapers must be changed often, and for the same reason."
The plug really should be in front, right in the center. Not sure why they tend to be on the side - as if you're going to pull up to a charging station and stand there pumping electrons for 6 hours.
A wireless charger. Talk about wasting energy. The low power ones are very inefficient and high power is even worse. An electric car to save energy and then charge it with a wireless charge...what a contradiction.
I hate getting out in the winter to fuel my car, so I'm going to open the remote-release gas cap and let the gasoline pump squirt fuel at it. Only a gallon or so per visit will be lost. No biggie.
10% loss is unacceptable.
damn how lazy are people