Wireless power transmission apparatus and method
A wireless power transmission apparatus includes a resonator configured to transmit power to another resonator, and a power supply unit configured to supply power to the resonator. The apparatus further includes a switching unit including a transistor configured to be turned on to connect the power supply unit to the resonator, and to be turned off to disconnect the power supply unit from the resonator, based on a control signal, and a diode connected in series to the transistor.
1. A wireless power transmission apparatus comprising:
a self-resonating resonator configured to transmit power to another resonator;
a power supply unit configured to supply power to the resonator; and
a switching unit comprising
a transistor configured to be turned on to connect the power supply unit to the resonator, and to be turned off to disconnect the power supply unit from the resonator, based on a control signal, and
a diode connected in series to the transistor.
2. The apparatus of claim 1 , further comprising:
a control unit configured to generate the control signal, and control an amplitude and/or a period of the control signal.
3. The apparatus of claim 2 , wherein the control unit is further configured to:
control the amplitude and/or the period of the control signal based on an amount of the power to be supplied to the resonator and an amount of energy stored in a load of the other resonator.
4. A wireless power transmission apparatus comprising:
a resonator configured to transmit power to another resonator;
a power supply unit configured to supply power to the resonator; and
a switching unit comprising
a transistor configured to be turned on to connect the power supply unit to the resonator, and to be turned off to disconnect the power supply unit from the resonator,
a diode connected in series to transistor,
wherein:
the diode and the transistor are configured to pass a direct current (DC) current signal from the power supply unit in response to the transistor being turned on; and
the diode is further configured to block an inflow of a positive component of an alternating current (AC) current signal from the resonator, and the transistor is further configured to block an inflow of a negative component of the AC current signal, in response to the transistor being turned off.
5. The apparatus of claim 1 , wherein:
the transistor comprises a P-channel metal oxide semiconductor (PMOS);
the control signal is applied to a gate of the PMOS;
the PMOS is configured to be turned on to connect the power supply unit to the resonator in response to a voltage of the control signal being less than or equal to a difference between a voltage applied to a source of the PMOS and a threshold voltage of the PMOS; and
the PMOS is further configured to be turned off to disconnect the power supply unit from the resonator in response to the voltage of the control signal being greater than the difference between the voltage applied to the source of the PMOS and the threshold voltage of the PMOS.
6. The apparatus of claim 5 , wherein:
the diode and the PMOS are configured to pass a direct current (DC) current signal from the power supply unit in response to the PMOS being turned on; and
the diode and the PMOS are further configured to block an inflow of an alternating current (AC) current signal from the resonator in response to the PMOS being turned off.
7. The apparatus of claim 1 , wherein:
the transistor comprises an N-channel metal oxide semiconductor (NMOS);
the control signal is applied to a gate of the NMOS;
the NMOS is configured to be turned on to connect the power supply unit to the resonator in response to a voltage of the control signal being greater than or equal to a sum of a voltage applied to a source of the NMOS and a threshold voltage of the NMOS; and
the NMOS is further configured to be turned off to disconnect the power supply unit from the resonator in response to the voltage of the control signal being less than the sum of the voltage applied to the source of the NMOS and the threshold voltage of the NMOS.
8. The apparatus of claim 7 , wherein:
the diode and the NMOS are configured to pass a direct current (DC) current signal from the power supply unit in response to the NMOS being turned on; and
the diode and the NMOS are further configured to block an inflow of an alternating current (AC) current signal from the resonator in response to the NMOS being turned off.
9. The apparatus of claim 1 , wherein:
the transistor comprises a bipolar junction transistor (BJT); and
the BJT is configured to be turned on to connect the power supply unit to the resonator, or to be turned off to disconnect the power supply unit from the resonator, based on a current of the control signal applied to a base of the BJT.
10. The apparatus of claim 9 , wherein:
the diode and the BJT are configured to pass a direct current (DC) current signal from the power supply unit in response to the BJT being turned on; and
the diode and the BJT are further configured to block an inflow of an alternating current (AC) current signal from a self-resonating of the resonator in response to the BJT being turned off.
11. The apparatus of claim 1 , further comprising:
a variable resistor disposed between the power supply unit and the switching unit.
12. The apparatus of claim 1 , further comprising:
resistors connected in parallel to the power supply unit; and
switches connected in series to the resistors, respectively.
13. A wireless power transmission method comprising:
turning a transistor on to connect a power supply unit to a self-resonating resonator, or turning the transistor off to disconnect the power supply unit from the resonator, based on a control signal, the transistor connected in series to a diode;
supplying power from the power supply unit to the resonator in response to the transistor being turned on; and
transmitting power from the resonator to another resonator.
14. The method of claim 13 , further comprising:
generating the control signal; and
controlling an amplitude and/or a period of the control signal based on an amount of the power to be supplied to the resonator and an amount of energy stored in a load of the other resonator.
15. The method of claim 13 , further comprising:
passing, through the diode and the transistor, a direct current (DC) current signal from the power supply unit in response to the transistor being turned on; and
blocking, by the diode and the transistor, an inflow of an alternating current (AC) current signal from a self-resonating of the resonator in response to the transistor being turned off.
16. The method of claim 15 , wherein the blocking comprises:
blocking, by the diode, an inflow of a positive component of the AC current signal; and
blocking, by the transistor, an inflow of a negative component of the AC current signal.
17. A wireless power reception apparatus comprising:
a resonator configured to receive power from another resonator;
a load configured to receive power from the resonator; and
a switching unit comprising
a transistor configured to be turned on to connect the resonator to the load and to terminate mutual resonance with the other resonator, and to be turned off to disconnect the resonator from the load, based on a control signal, and
a diode connected in series to the transistor.
18. The apparatus of claim 17 , wherein:
the diode and the transistor are configured to pass a direct current (DC) current signal based on an alternating current (AC) current signal from the resonator in response to the transistor being turned on; and
the diode and the transistor are further configured to block an inflow of the AC current signal in response to the transistor being turned off.
19. The apparatus of claim 17 , further comprising:
a control unit configured to generate the control signal, and control an amplitude and/or a period of the control signal based on an amount of the power to be received by the load.
20. A wireless power reception apparatus comprising:
a resonator configured to receive power from another resonator;
a load configured to receive power from the resonator;
a switching unit comprising
a transistor configured to be turned on to connect the resonator to the load, and to be turned off to disconnect the resonator from the load, based on a control signal, and
a diode connected in series to the transistor; and
a capacitor,
wherein the transistor is further configured to be turned on to connect the resonator to the capacitor, and to be turned off to disconnect the resonator from the capacitor, based on the control signal, and
wherein the capacitor is configured to change a resonant frequency of the resonator in response to the capacitor being connected to the resonator.
21. The apparatus of claim 17 , further comprising:
a capacitor,
wherein the transistor is further configured to be turned on to connect the resonator to the capacitor, and to be turned off to disconnect the resonator from the capacitor, based on the control signal, and
wherein the capacitor is configured to change a resonant frequency of the resonator in response to the capacitor being connected to the resonator.
22. The wireless power transmission apparatus of claim 1 , wherein the resonator self resonates and mutually resonates with the other resonator in response to the transistor being turned off.
23. The wireless power transmission apparatus of claim 1 , wherein the control unit is configured to change a thickness of a channel via which a current is moved in the transistor and a resistance of the transistor.
24. The wireless power transmission apparatus of claim 1 , wherein the control unit is configured to increase an amount of current transferred from the power supply unit to the resonator by increasing the period of the control signal.
25. The wireless power transmission apparatus of claim 1 , wherein the control unit is configured to adjust an amount of power transferred from the power supply unit to the resonator by adjusting the amplitude of the control signal.
26. The wireless power transmission apparatus of claim 1 , wherein power is supplied to the resonator without rectification.
27. The wireless power transmission apparatus of claim 1 , wherein the transistor is configured to be turned on to connect the power supply unit to the resonator to store power in the resonator, and to be turned off to disconnect the power supply unit from the resonator with the stored power to cause the resonator to begin self-resonating.