Hi David, The following book is from the 1940s, has (I think) the info you want, and is cheap and easily available. The only downside is that it is very dense and it will take a while to figure out exactly which cases it covers are most applicable to your situation and what modifications to his formulas you'll have to make in order to fit the example to your exact case: https://www.amazon.com/Inductance-Calculations-Dover-Electrical-Engineering= /dp/0486474402 Sean On Tue, Apr 4, 2017 at 2:08 PM, Van Horn, David < david.vanhorn@backcountryaccess.com> wrote: > I am looking for documentation describing the coupling of inductors which > are physically separated, and oriented at 90 degrees, yet as Q is > increased, suddenly become coupled such that tuning one LC pair tunes the > other pair. > > I suspect this is either in the domain of wireless charging, or it's > buried back in something done between 1920 and 1940. > > Any ideas? > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com backcountryaccess.com> > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .