VOLTAGE SOURCE ISOLATION IN WIRELESS POWER TRANSFER SYSTEMS
The disclosure features wireless power transmitters that include a power source, a first coil connected to the power source, a second coil connected in series to the first coil, and a third coil positioned in proximity to the second coil, where during operation of the wireless power transmitters, the power source applies a driving voltage to the first and second coils, the first coil generates a first magnetic field that transfers power to a receiver resonator, the second coil generates a second magnetic field that induces a voltage across the third coil, and the induced voltage across the third coil is applied to a component of the wireless power transmitters.
1 . A wireless power transmitter, comprising:
a power source;
a first coil connected to the power source; and
a second coil positioned in proximity to the first coil,
wherein during operation of the wireless power transmitter:
the power source applies a driving voltage to the first coil;
the first coil generates a magnetic field that transfers power to a receiver resonator;
the magnetic field induces a voltage across the second coil; and
the induced voltage across the second coil is applied to a component of the wireless power transmitter.
2 . The transmitter of claim 1 , wherein each of the first and second coils comprises one or more loops of conductive material.
3 . The transmitter of claim 1 , wherein the component comprises at least one of a resistive element of the wireless power transmitter, a capacitive element of the wireless power transmitter, an inductive element of the wireless power transmitter, a switch of the wireless power transmitter, and a component of an impedance matching network of the wireless power transmitter.
4 . The transmitter of claim 1 , wherein the component comprises a transceiver configured to generate an information carrying signal.
5 . The transmitter of claim 1 , wherein the component comprises a third coil configured to generate an information carrying magnetic field that, during operation, is received by a fourth coil connected to the receiver resonator.
6 . The transmitter of claim 5 , further comprising a modulator configured to modulate the induced voltage to generate the information carrying magnetic field.
7 . The transmitter of claim 6 , wherein the induced voltage corresponds to an oscillating voltage signal, and wherein the modulator is configured to modulate at least one of an amplitude and a frequency of the oscillating voltage signal to generate the information carrying magnetic field.
8 . The transmitter of claim 1 , wherein a magnitude of the induced voltage is 1% or less of a magnitude of a voltage induced in the receiver resonator, and wherein the induced voltage is not referenced to a ground voltage of the wireless power transmitter.
9 . The transmitter of claim 1 , further comprising a third coil positioned in proximity to the first coil, wherein during operation of the wireless power transmitter:
the magnetic field induces a voltage across the third coil; and
the induced voltage across the third coil is applied to a second component of the wireless power transmitter.
10 . The transmitter of claim 9 , wherein the second component comprises at least one of a resistive element, a capacitive element, an inductive element, a switch, a component of an impedance matching network, a transceiver configured to generate an information carrying signal, and a fourth coil configured to generate an information carrying magnetic field that, during operation, is received by a fifth coil connected to the receiver resonator.