Qi charging through wood?

[AC Question]

Hey I was wondering if qi charging would work through 2cm of wood and if anyone knew of a good charger that can do this and is 4cm wide (not thick) or thinner?

 

[zedorda]

Under the Qi specification, "low power" for inductive transfer means a draw of 0 to 5 W. Systems that fall within the scope of this standard are those that use inductive coupling between two planar coils to transfer power from the power transmitter to the power receiver. The distance between the two coils is typically 5 mm. It is possible to extend that range to at least 40 mm.

How you extend teh range from 5mm to 4cm I don't know. I don't believe wood would block the signal much.

 

[chris_1204]

Thx, I read somewhere about how it could pass through non conductive materials but I wanted to check, I also read about one that could transfer over a few feet

 

[chris_1204]

Do you know of a qi charger with over a 2cm range?

 

[Brayden McGraw]

I am wondering the same question as I am going to put a custom made wood back on my 7 if I get the transmitter and put a small slit in the back of the phone to hide the transmitter the small slit can can connect to the lightning port. But my question would be if I do that do you think that it would catch fire since energy is going through the wood?

 

[Rukbat]

If the wood is totally dry (hasn't absorbed moisture from the air), 2cm is just over one inch, and that's about the limit for Qi. Depending on the charger, you might be a mm or two too far for it to work. If you could make the wood about 17mm or thereabouts, it will probably work. As for the width, if the wood is dry, 4mm or 4 meters wouldn't make any difference - it's the thickness and the electrical conductivity of the wood that matters. (I've gotten close to an inch [by eye - I never measured it] by holding my phone [in a pretty thick case, an Otterbox] above the charging plate, so 0.787 inches (2 cm) would probably work with dry wood. The only way to find out is to put the wood on the charger plate and see. (The coil can be melted into the top plate, giving you less than 1mm minimum distance, or it could be mounted a few mm under the plate, putting it just too far to work reliably.)

@Brayden McGraw, if the wood is dry, there's nothing to catch fire - the wood needs heat, not electricity, to catch. But if the wood gets wet, the water in it will heat up - possibly enough to catch. Soak the wood in a waterproof varnish (polyurethane varnish or marine spar varnish) overnight to make sure that doesn't happen.