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Induction Coupling to transfer power through glass

Induction Coupling to transfer power through glass

Induction Coupling to transfer power through glass

(OP)
I've been struck with the tinkerer's curse.

I am working on an idea to transfer power from a small bank of solar cells outside, through a window, and to a small battery pack/charger on the inside.

I only have conceptual ideas how to go about this. I don't even really know where to start looking. I've scoured instructables, because that's a suprizingly good source of "tinkerer level" information, but haven't come across anything that seems to lead me to a possibly realistic outcome.

Considerations:
1) No physical contact allowed from inside circuit to outside circuit
2) Power needs to be transmittable through a single sheet of glass, as well as through double paned glass.
3) The whole contraption needs to be able to run from the voltage available from the solar cells while leaving enough to charge 12v worth of AA size rechargables (not NiCD....NiMH or Lithium Ion, maybe LiPoly's in the future)

I don't know how shapes and sizes of the tx/rx coils affect things, or distances, voltage/current/amps, any of that really. I'm trying to acertain if the whole creature is even feasable, without my mind exploding from info-overload.

What other information might y'all need to help me visualize this thing?

Much much appreciated!
Byron

Byron Morgan - Tupelo, Mississippi
1947 Mayline
SolidWorks 2008
NX4

RE: Induction Coupling to transfer power through glass

Pot cores are usually employed for this kind of applications.

As long as the air gap (distance between the core halves) is small in relation to the core diameter, there is a fair chance of making it happen. One pane probably feasible. But two panes at a a distance will mean trouble.

The electric car chargers sometimes work with a similar arrangement (although double-sided, which is an advantage). Electric tooth brushes also have this, but then again with the magnetic circuits in a more favourable design.

It does work. But the efficiency may be too low for your purposes. Also, EMI may be an issue since you will be working with HF magnetic fields.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: Induction Coupling to transfer power through glass

Use optical wavelengths instead. The exterior solar panels drive a very powerful light aimed through the window. Then inside arrange a bank of solar panels...

Ah, oh - disregard.

winky smile

RE: Induction Coupling to transfer power through glass

(OP)
Well, I'd thought that my loss by having the solar inside the glass would be less than with the transferring, but then I considered that the position of the window could cost me even more. If that window, for instance, is under a long eve or a porch, in the north of the house, etc, places that don't get the best of natural light, would the entire system suffer so much loss that it wouldn't work?

That's why I was looking toward external solar and power transfer. I kinda hate to do hardwire, some folks get twitchy about having holes drilled in their million dollar walls (if you don't believe their walls are a million, just ask them). That way the panel can be placed in a more suitable spot to gather the most.

Suggestions?

Byron Morgan - Tupelo, Mississippi
1947 Mayline
SolidWorks 2008
NX4

RE: Induction Coupling to transfer power through glass

Optical transmission is basically impractical.  You're going to lose 95% of the available energy through generation loss, transmission loss, detection loss, and conversion loss.

TTFN

FAQ731-376: Eng-Tips.com Forum Policies

RE: Induction Coupling to transfer power through glass

winky smile !!!

RE: Induction Coupling to transfer power through glass

Optical transmission could work if you had a large parabolic mirror that tracked the sun and reflected the light into the window.  Of course, it may also set the house on fire or blind the occupants.

RE: Induction Coupling to transfer power through glass

If "hating doing hardwiring" and bothering about people not wanting wires run from outside to inside their houses are your main problems, then you are a very very lucky guy.

You may have to accept those wires. They are efficient, proven and low cost.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: Induction Coupling to transfer power through glass

Jeez Gunnar, spoken like a true engineer.  Unfortunately for you, here on earth the consumers dictate, not engineers.

Here is a way to get 2 Ghz thru a window efficiently.  Perhaps you can do something similar.  You would need to have a very efficient oscillator to turn the DC into RF, perhaps class E?

http://www.crutchfield.com/S-ENZvapuKAxe/App/Product/Item/Main.aspx?s=0&cc=01&c=3&g=102500&I=019XM8100F

RE: Induction Coupling to transfer power through glass

I think there were some microwave lighting devices that used super-efficient oscillators.  You could look them up.

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