I received this big, beautiful vase for a present, and it is slim and tall, about two feet or 0.6 meters tall. Its base is narrow and it easily would fall over if it was not fastened down to something. I got an idea that it would make a great lamp base. I’ve watched Antiques Roadshow and know from what they say that it reduces the value of a vase if there is a hole drilled in the bottom for the wires fom the lamp. I figured that there should be another way of transferring power to the light than making a hole in the base for wiring. Thus the idea for transferring the power through the base of the vase wirelessly, or more appropriately, with an electromagnetic field.
An older lamp might have a 60 to 150 watt lamp in the socket, too much power to easily send to a light bulb. But today this same lamp could use a LED light bulb, which might take only 8 to 16 watts of power. This is low enough to allow the power to be transmitted from the AC line to the lamp through a pair of coils in the base of the lamp. No holes need to be drilled if this is used.
I have some tough problems to solve. The neck of this vase is narrow, only about an inch (25 mm) inside diameter. So whatever coil is used, it would have to fid through this hole. The coil could be made into a rectangle that is long and narrow, just narrow enough to fit through the hole. The coil on the outside would have to be similar to this inside one.
I could directly feed the AC line into an air core coil, but the coil would require many turns of fine wire to make it the right inductance value. A lot of power would be wasted in the resistance of the coils due to the fine wire. It would be better if the coils had a core made out of some transformer material, such as laminations. The coils would then require much less wire and the lower resistance would mean lower losses and better efficiency.
Another idea would be to change the 50 or 60 Hz AC line current to a higher frequency. The coils could be much smaller and still be very efficient. But this would require that the AC be rectified, filtered, and then changed to AC at a higher frequency. My guess is the frequency should be higher than audio frequencies, maybe 20 to 30 kHz.