Hi all,
I'm in the middle of a project to design an inductive charging system. For the primary circuit, I've got an RLC circuit that transfers power to the secondary coil when at the resonant frequency.
The problem is that, for this project, the distance between the two coils isn't always the same, so the mutual inductance can change, effectively changing the resonant frequency. So if I have the primary circuit by itself perfectly tuned to the supply, when I bring the secondary coil close to the primary, it's not tuned anymore.
Is there any way I can make the primary circuit automatically adjust itself so that it stays tuned? I guess this could either be done by automatically adjusting the capacitor, or adjusting the supply frequency?
This is going to be quite important once I start trying to design switching circuits to drive the primary coil (up to now, I've just been powering it from a function generator), because if the circuit isn't tuned, then the current and voltage will be out of phase, and the switching device will end up wasting a lot of power and overheating.
If anyone can help, it would be much appreciated!
Thanks
I'm in the middle of a project to design an inductive charging system. For the primary circuit, I've got an RLC circuit that transfers power to the secondary coil when at the resonant frequency.
The problem is that, for this project, the distance between the two coils isn't always the same, so the mutual inductance can change, effectively changing the resonant frequency. So if I have the primary circuit by itself perfectly tuned to the supply, when I bring the secondary coil close to the primary, it's not tuned anymore.
Is there any way I can make the primary circuit automatically adjust itself so that it stays tuned? I guess this could either be done by automatically adjusting the capacitor, or adjusting the supply frequency?
This is going to be quite important once I start trying to design switching circuits to drive the primary coil (up to now, I've just been powering it from a function generator), because if the circuit isn't tuned, then the current and voltage will be out of phase, and the switching device will end up wasting a lot of power and overheating.
If anyone can help, it would be much appreciated!
Thanks