Tagged Questions
4
votes
1answer
239 views
Transfer power effectively from one coil to another through air
I want to build my own wooden alarm clock.
I want the surface to be smooth without any connectors anywhere. My idea is to place one coil beneath the alarm clock, and another pickup coil inside. I ...
4
votes
1answer
261 views
Is it possible to have a device with metal case and wireless charging?
Recently I encountered the following idea: that a mobile device manufacturer is not interested in including wireless charging in his devices because that prohibits him from using metal cases in the ...
2
votes
2answers
713 views
Is there any difference between “induction” and “resonant” wireless energy transfer?
This article compares two systems for wireless energy transfer - one is by WiTricity and another is Bombardier PRIMOVE. I've read their descriptions thoroughly - to me they both look like resonant ...
6
votes
4answers
555 views
How is inductive wireless charging of a moving vehicle on a public road possible in efficient way?
Looks like one of the major problems of wireless energy transfer is efficiency. For example, Magne Charge high power charging system seems to have about 86% efficiency which means that quite a lot of ...
3
votes
1answer
328 views
What's the need for higher frequency in inductive charging systems?
Consider an inductive charging system like Magne Charge - it has a rather huge "coupler" coil off the vehicle and a corresponding slot on the vehicle and the coils in the "coupler" and in the slot are ...
7
votes
1answer
278 views
Why does short distance wireless energy transfer have such low efficiency?
Wikipedia and numerous other sources cite the following statement about Magne Charge high-power inductive charging system:
For example, the Magne Charge system employed high-frequency induction to ...
5
votes
2answers
598 views
How do snap-on induction charging systems not interfere with device functioning
There's a variety of snap-on wireless charging solutions on the market. For example, this one includes a charging mat and a plastic case that is put onto iPhone.
I suppose the winding is in the ...
1
vote
1answer
349 views
What's the technical limit to how small RFID-like system antenna can be?
So far I haven't seen a contactless smart card smaller than a standard credit card. My "biometric" travel passport holds a chip powered off the antenna - I lit the plastic holding the chip through ...
6
votes
4answers
668 views
How does a wireless charger work without a magnetic core passing through both “coils”?
Every time I hear the description of a wireless charging system it goes like this: "remember a transformer? It's the same here - one coil is in the base and another is in the device and when you put ...
3
votes
4answers
371 views
Why don't we have wireless charger in every portable device yet?
Today I found Texas Instruments announced a circuit for wireless charging - all the materials emphasis how tiny, lightweight, portable, efficient and otherwise cool it is.
While I of course like the ...
2
votes
1answer
427 views
Safely connecting an solenoid/electromagnet to a switch-mode supply
I'm currently working on a project that involves hooking up an arduino, a cellular shield, and an electromagnet (in this case, one of those old fashioned ringer boxes with a bell powered by ...
