同学你到底算是八卦男还是算是学术男呢? 我陷入了沉思 ...

It turns out that there are commercial products already: http://gigaom.com/2009/10/23/wireless-power-is-still-pretty-useless/

i was talking about this: http://www.themirasoleffect.com/
but yeah, qualcomm definitely has a lot of money to burn and one of those projects may actually launch into something big.

Previously, I heard from someone who did intern in Qualcomm that they are doing something on 3D monitor, maybe just this one: http://www.allbusiness.com/electronics/computer-electronics-manufacturing/6297476-1.html
also very interesting.

wireless charging确实是一个attractive的东东。要说这个东西不可能没人想过要做，归根到底可能还是安全和损耗的问题。距离问题本质上也是个损耗问题, 如果能做到10m以内50%，那么还是很不错的。不过我肯定还是不会着急用这个玩意的，junjun你先试用一下先，哈哈

不过说起qualcomm做的很多东西还是很impressive的，感觉qualcomm现在和google有点像，CDMA那边靠专利抓了一大笔钱，现在就有闲情来搞各种R&D。前几个月看到他们在做的一个新一代显示器的project, 也很fancy的样子。

是不是原理跟微波炉差不多啊？

qualcomm 做成盘子的样子只是方便你放置手机啊啥的，不是说一定要接触到才能开始充电滴。。。你拿着手机靠近那个‘盘子’其实就已经开始充电了，可是你总不想在那儿一直举着手机吧。。。所以说确实是wireless charging啦，好像他们说是充满电要半个小时还是啥的，忘了，反正不会比现在的充电速度慢很多。但是。。。如果放了几个手机的话当然就慢下去了。。。

well, I just find it's interesting. Glad to see lots of replies on this post. If it works well, i.e. omni-directional, power efficient, low cost, then absolutely it will play a role. Let's see how good we can make it.

还是阿军这边的学术氛围浓hoho～
to Yingda同学：谢谢提醒，我刚检查了一下笔记本电源，之前把输入当输出了，输入是100－240~ 1.6A,输出是65W。BTW，这么着输入是160W了，难道我的开关电源耗了差不多100W还是我算错了。。。OMG。。。
还有两个问题：1是功率和距离的问题，具体数值记不得了，感应线圈获得的功率是随距离成指数递减的，正对情况下，大概两个平行线圈的距离是线圈边长的1/10以内的情况下，功率传输大概可以达到1：1这个数量级。就是说，如果50cm边长的线圈，两个线圈正对，并且距离5cm以内，大概你发射4W或许可以接收4W，线圈匝数和电阻损耗啥的暂不考虑。然后，功率传输效率就是随着距离成指数递减了，大概距离50cm的情况下获得的功率<0.4W.上述分析还是发射线圈和感应线圈的尺寸都是50cm的情况。
第二个问题是全方向性：全方向的线圈是有的，基本上就是做成8字形的天线，然后要有一堆电路控制不同回路的电流相位。05年底的时候国内公司买过一个，8万还是12万 RMB。给手机冲个电实在成本太高。。。

目前这种技术的应用在超市防盗门，RFID识别主要是物流领域，高速公路自动收费等。

if it is not omni-directional, then maybe it is nothing more than an eye-catcher...

but i bet to disagree that one needs to provide ~100W wirelessly to make the technology useful. most cellphones can be charged at less than 5W input. if you think about it, standard USB provides 5V at maximum <1A: u can use that to charge almost every mobile device. in fact, ~2W is probably enough to get most phone going, just charging slower.

the big turn-off is that the thing being one-directional, which i am not sure though. if they can make it omni-directional, then there are still tremendous potentials at <4W power. not that you can use it to light up a light bulb, but that is not what makes this attractive anyway. i will be all over it if it can charge my mobile device SAFELY (a.k.a, without burning my brain....) without wires.

btw: you should check your numbers, i seriously doubt any 12inch laptop runs at 160W, you will be burning yourself if you put such laptop on your lap...:-) my x60 runs at 65W peak, and most of time it is <30W.

昨天和朋友讨论了一下这个问题，目前得出两点结论：
1、没有找到有价值的应用领域，通俗点说：没用。
2、安全性是大问题，以我12寸的笔记本为例，功率160W左右，如果能够满足这种供电需求，就要求无线power传输功率大于这个数值。我以前做RFID，13.56MHz的美国安全标准是4W，欧洲安全标准是10W。在这种耦合传输的无线传输中（散射的功率要更大），除了手机这种小玩意儿大概可以在4W以下。说白了。。。实在没啥用。。。
努力找找无人环境中的应用似乎还有点前途。。。

to楼下的Yingda同学，这个video演示的也不是omni—directional,两个线圈必须平行正对，这种情况在RFID领域中被称为one-directional。从演示的情况判断，频率应该在10MHz的数量级上，应用距离<1m，似乎最大可以到2m。

做成盘子状扔进去充电/方向性充电和这个video里面的demo难度估计要低一些，现在很多接触性的充电器（比如电动牙刷，剃须刀）几年前就已经实现了这种功能。这个video展示的是真正的无线充电，是有一定的距离的而且omni-directional。this is what makes it new and impressive. But then again, I am really doubtful if staying in a house full of magnetic field used for wireless charging is harmless....wouldn't that burn your brain?...somehow...

有次去qualcom visit的时候，他们show的其中一个正在研发的product就是wireless charger，不过跟这个vedio里的原理不同啦，是跟下面yang同学说的差不多的。他们有演示做成的成品，盘子一样，然后手机扔进去就开始充电，还有做成放在桌子下面的，手机扔到桌子上就开始充电，看着还挺有意思的。好像当时是在努力通过safety的要求。。。现在通过没有。。。不知道了。

终于发现有人讨论偶们track的问题了，呵呵～

Our lab initiated research on wireless power transfer about two years ago...
Trying to use different antennas to substitute the coil inside the video.
Quite interesting but there are a lot issues, distance is one of them.
Also safety is another concern.

use wireless to transfer power? oo

yes, it's amazing. I heard about it before, but didn't expect it works so well as in this demo. Seems lots of companies are interested in this.

very impressive...if this is really as safe as he claims and comes at reasonable size/efficiency, this thing is going to be HUGE...
i am still a bit suspicious about the safety though...let's see how things roll out...