A major point that is missed in the toothbrush circuit that doesn't
matter so much there but which does in more general applications is
that the receive circuit will get VASTLY more range if it is resonant.
Vastly.
If you can get the two "transformer core halves" in close proximity
then resonance is not absolutely essential, but still a good idea. At
any range you must have resonance for any significant power transfer
at all.

I have many more refs and comments in this area if of enough interest.
I have the MITS metres range PhD paper and refs here somewhere.
And much more.

Excellent advice in Microchip AN710
AN710 Antenna Circuit Design for RFID Applications

               http://ww1.microchip.com/downloads/en/AppNotes/00710c.pdf

______________________


These should open up some mental filters :-) :

_____________

NOT powering but YEE HA !!!!!!!!!!!!!!!!!!!!!!!!!!  (2mm dia, 80
turns, 14 micro wire, fly-flown ... :-) )

Using miniature sensor coils for simultaneous measurement of
orientation and position of small, fast-moving animals
C. Schilstra, J.H. van Hateren *
Department of Neurobiophysics, Uni6ersity of Groningen, Nijenborgh 4,
Groningen, NL-9747 AG, The Netherlands Received 19 January 1998;
accepted 9 March 1999

           http://iwi.eldoc.ub.rug.nl/FILES/root/1998/JNeurscMethSchilstra/=
1998JNeurosciMethSchilstra.pdf

And:
BLOWFLY FLIGHT AND OPTIC FLOW
I. THORAX KINEMATICS AND FLIGHT DYNAMICS
C. SCHILSTRA AND J. H. VAN HATEREN*
Department of Neurobiophysics, University of Groningen, Nijenborgh 4,
NL-9747 AG Groningen, The Netherlands

             http://jeb.biologists.org/content/202/11/1491.full.pdf
________________________________


AN710  Antenna Circuit Design for RFID Applications
http://ww1.microchip.com/downloads/en/AppNotes/00710c.pdf


Modeling and Optimization of Printed Spiral Coils in Air, Saline, and
Muscle Tissue Environments
Optimization of Data Coils in a Multiband Wireless Link for
Neuroprosthetic Implantable Devices     RRD Ref6b


http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3171452/pdf/nihms305002.pdf


A Closed Loop Wireless Power Transmission System Using a Commercial
RFID Transceiver for Biomedical Applications

               http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953772/pdf/nihm=
s235191.pdf


Design and Optimization of a 3-Coil Inductive Link for Efficient
Wireless Power Transmission.
Abstract only - if anyone has a full version I'd love to see it.

          http://www.ncbi.nlm.nih.gov/pubmed/21922034

             http://ieeexplore.ieee.org/Xplore/login.jsp?url=3Dhttp%3A%2F%2=
Fieeexplore.ieee.org%2Fiel5%2F4156126%2F4358093%2F05951804.pdf%3Farnumber%3=
D5951804&authDecision=3D-203
Kiani, M.=A0 Jow, U.-M.=A0 Ghovanloo, M.

                 http://lib.bioinfo.pl/pmid:21922034



An Inductively Powered Scalable 32-Channel=A0Wireless=A0Neural Recording
System-on-a-Chip=A0for=A0Neuroscience Applications.
=09
         http://lib.bioinfo.pl/pmid/journal/Dig%20Tech%20Pap%20IEEE%20Int%2=
0Solid%20State%20Circuits%20Conf


A TRANSCEIVER FOR DIRECT PHASE MEASUREMENT MAGNETIC INDUCTION TOMOGRAPHY

             http://www.dtic.mil/cgi-bin/GetTRDoc?Location=3DU2&doc=3DGetTR=
Doc.pdf&AD=3DADA411517


NON-CONTACT MEASUREMENT OF THE ELECTRICAL IMPEDANCE OF BIOLOGICAL TISSUE

           http://www.dtic.mil/cgi-bin/GetTRDoc?Location=3DU2&doc=3DGetTRDo=
c.pdf&AD=3DADA409909



No prizes for guessing what I've been looking at lately :-)


           Russell McMahon
           Applied Technology ltd
           New Zealand



On 29 November 2011 11:15, David <lists@edeca.net> wrote:
>
> Hello,
>
> I'm looking at DIY inductive charging, to top up small batteries.
> Undecided on the actual battery so far, I'm more interested in the
> inductive side for now. =A0Perhaps an AAA or LIR2032.
>
> I've seen a few pages such as this one:
> http://donklipstein.com/samschem.htm#schras4
>
> Has anybody made a small inductive charger that worked? =A0I would be
> interested in any pointers.
>
> David
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist

--=20
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View/change your membership options at
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