wireless charging coil size
The transmitter board always gets really hot and smells faintly of something burning. Is this normal? Should I use some type of heat sink?
Anyway, I discovered that you can add another coil of the same-ish size to the transmitter, and both coils will work. However, if I remove the coil and add a single coil twice the size, it does not work. I'm curious as to why. What determines how large the coil can be?