I am making a device that will be wireleslly charged and I decided to go for a standardized Qi transmitter/receiver. The device is a kind of bulk and I want it to have an option to get charged no matter what side it is lying on. I thought of putting a Qi coil on each side and getting the charging voltage on battery port when the device is lying on any side.
Let's say there will be 3 coils. How do I connect them to the same battery charging circuit? If I connect them in parallel, 2 coils will present huge load to the one coil that is currently active. If I connect them in series, It will present additional impedance to the source and may limit the output current.
I thought of putting them in parallel and adding a diode in series to each branches. This way, the diode is going to be reversly polarized when one coil is active and there will be no overload. But at the same time, it will work as rectifier and kill all negative half-periods when it's conductive.
Is there any reasonable way to do this?