datasheets.com EBN.com EDN.com EETimes.com Embedded.com PlanetAnalog.com TechOnline.com  
Events
UBM Tech
UBM Tech

Design Article

Comment


MODULATE

11/2/2012 4:30 PM EDT

It's Called the Tesla "field of distortion!" ;)

More...



iniewski

11/1/2012 2:18 PM EDT

I understand Frank...perhaps Tesla or someone knowledgeable in this field could ...

More...

Who holds power in wireless charging?

Peter Clarke

10/30/2012 4:56 PM EDT

Japan is moving towards Qi

WPC chairman Menno Treffers believes that critical mass is on his group's side. Already there are 8.5 million Qi-enabled products, covered by 110 certified designs, in circulation. About 2 million of those are in Japan according to WPC.

"In Japan Qi is definitely catching on. NTT Docomo has said it will be in all its smartphones." Also, Treffers said, Samsung includes a couple of pins in the battery compartment of the Galaxy S3 ready for wireless charging.  

And Treffers argues that, ultimately, it will be the mobile phone makers and mobile network operators that will define how wireless charging is implemented. "The carriers and mobile phone companies don't want to be locked-in or expected to pay patent license royalties. The Wireless Power Consortium is royalty-free," he said.

"There will be a free market because an open standard is better than a proprietary situation," he added.

There is still one major name in mobile devices that is uncommitted and that has a history of doing things in a proprietary way.

"If Apple wants to do wireless charging they could go proprietary – like the Apple connector. Similarly an Android standard could co-exist for a while. But the charging market will end up converging to a single standard," Treffers said.

Treffers is convinced the convenience of wireless charging, and avoiding carrying multiple proprietary wired chargers will eventually drive adoption. But he acknowledges there is a trade-off between convenience and energy consumption, because wireless charging cannot be 100 percent efficient.

Typical wireless energy transfer efficiencies are about 70 percent going up to 80 to 85 percent efficient with careful design, more copper and better shielding, Treffers said.


Related links and articles:

www.wirelesspowerconsortium.com


www.a4wp.org

News articles:

Qualcomm, Samsung form wireless power alliance

How Intel can use wireless charging to attack ARM

IDT charges ahead with Intel on wireless power





Comfortable

10/31/2012 11:37 AM EDT

Apple has already said they have no plans for wireless charging. And their reasoning is sound: one still needs to plug a charger into the wall.

And as far as a universal charging standard: that already exists. It's called USB and is used by everyone in the business.

If wireless charging makes sense, it will be in applications that are similar to a toothbrush - a charging solution that's been around for more than one decade.

Sign in to Reply



Doug S

10/31/2012 4:51 PM EDT

I have to agree with them. Wireless charging isn't more convenient - it's not like the extra two seconds to plug in your device is a big deal. Having multiple chargers in the locations you need them is cheaper than having multiple charging mats.

A bigger factor is travel. Do you want to carry around a charging mat, along with the power adaptor to plug it into the wall, or just the power adaptor?

Wireless charging is a problem looking for a solution. Perhaps there are certain types of devices where it makes sense (electric toothbrushes as you mention) but for mobile phones and tablets I think it is just a fad popular for bragging rights. Once the "look what my cool new phone can do" factor wears off, few will care about it enough to consider it a "must have" when making purchase decisions.

Sign in to Reply



Comfortable

10/31/2012 11:44 AM EDT

...forgot to comment why a toothbrush-type application makes sense. This is an application where the charger functionality is hidden. The toothbrush charger is primarily a storage socket to keep your toothbrush off the counter - and oh by the way it also charges. A portable phone doesn't always sit on the charger pad. You have to go out of your way to put your phone where you normally don't store it.

Another bigger application is a floormat electric car battery charger. Again, you park you car on the garage floor - and oh by the way the mat on the floor couples the charge while you are parked.

Sign in to Reply



Frank Eory

10/31/2012 5:42 PM EDT

You don't always still have to plug a charger into the wall. You guys are missing an obvious one -- a wireless charging mat built into the center console of your car. Sure it "only" eliminates the need to have to plug a phone charger into the cigarette lighter, and deal with the annoying wire that always seems to interfere with the cup holder.

As for the EV charging mat on the garage floor, I saw that demo at CES 2011. It was cool, and the convenience and safety relative to plugging the car into the wall just might be worth the loss in efficiency.

Sign in to Reply



Doug S

10/31/2012 6:54 PM EDT

Correct me if I'm wrong, but isn't the efficiency loss for wireless charging pretty sizable? That's irrelevant for charging a phone, but for charging a CAR? Not to mention that it is already difficult to deliver sufficient power to a car to charge it in a reasonable amount of time when wired; charging a car wirelessly makes that problem far worse.

I agree with you that wireless charging of a phone in the car is reasonable, but only for that minority for whom phones don't last through the day. I think the best solution to having a phone that needs to be charged during the day is to get a better phone, swap batteries, or get a case with additional battery capacity built in...

Sign in to Reply



Frank Eory

10/31/2012 7:18 PM EDT

I thought the same thing before I talked to the guys at CES that demo'd this with a Tesla Roadster. They said that with an integrated wireless charging system designed into the car, rather than an add-on like they had at CES, they could get 93% efficiency, and their gap distance between the mat and the secondary winding in the car was 4 inches, which is quite reasonable for that application.

7% loss is indeed significant when you're measuring power in kilowatts, but like I said, it might be worth it for the added convenience & safety.

Sign in to Reply



iniewski

11/1/2012 1:24 PM EDT

93% efficiency??? since radiation propagates in all directions how do you get such a high number?

Sign in to Reply



Frank Eory

11/1/2012 2:05 PM EDT

Not my number. I'm just reporting what was claimed.

Sign in to Reply



iniewski

11/1/2012 2:18 PM EDT

I understand Frank...perhaps Tesla or someone knowledgeable in this field could shed some light here

Sign in to Reply



MODULATE

11/2/2012 4:30 PM EDT

It's Called the Tesla "field of distortion!" ;)

Sign in to Reply



Please sign in to post comment

Navigate to related information

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)