초록 ▼

A contactless power supply has a dynamically configurable tank circuit powered by an inverter. The contactless power supply is inductively coupled to one or more loads. The inverter is connected to a DC power source. When loads are added or removed from the system, the contactless power supply is ca

A contactless power supply has a dynamically configurable tank circuit powered by an inverter. The contactless power supply is inductively coupled to one or more loads. The inverter is connected to a DC power source. When loads are added or removed from the system, the contactless power supply is capable of modifying the resonant frequency of the tank circuit, the inverter frequency, the inverter duty cycle or the rail voltage of the DC power source.

대표청구항 ▼

The invention claimed is: 1. A method of operating a contactless power supply to power a load, the contactless power supply having a tank circuit on a primary side, the tank circuit having a resonant frequency, the tank circuit also having an operating parameter, the tank circuit being inductively

The invention claimed is: 1. A method of operating a contactless power supply to power a load, the contactless power supply having a tank circuit on a primary side, the tank circuit having a resonant frequency, the tank circuit also having an operating parameter, the tank circuit being inductively coupled to the load on the secondary side, wherein the tank circuit is coupled to an AC power source, the AC power source having an AC power source frequency and a duty cycle, where the AC power source is coupled to a DC power source having a rail voltage, the method comprising: changing the resonant frequency of the tank circuit on the primary side in response to changes of the operating parameter in the tank circuit on the primary side; and changing, on the primary side, at least one of the AC power source frequency, the AC power source duty cycle, and the DC power rail voltage in response to changes of the operating parameter in the tank circuit on the primary side. 2. The method of claim 1 where the tank circuit has an adjustable capacitor having a capacitance, and the changing the resonant frequency of the tank circuit step includes changing the capacitance of the adjustable capacitor. 3. The method of claim 1 where the tank circuit has an adjustable inductor having an inductance, and the changing the resonant frequency of the tank circuit step includes changing the inductance of the adjustable inductor. 4. A method of operating a power supply on a primary side to power a load on a secondary side, the power supply having a tank circuit and an inverter supplying power to the tank circuit, the tank circuit configurable by a controller to have a first resonant frequency or a second resonant frequency, the tank circuit also having an operating parameter having a nominal range in which the power supply is operating efficiently, the tank circuit being inductively coupled to the load, the inverter having a first inverter frequency and a second inverter frequency, the method comprising: configuring the tank circuit on the primary side to have the first resonant frequency; operating the inverter on the primary side at about the first inverter frequency; sensing the operating parameter on the primary side; configuring the tank circuit on the primary side to have the second resonant frequency if the operating parameter on the primary side is not within the nominal range; operating the inverter on the primary side at about the second inverter frequency if the operating parameter on the primary side is not within the nominal range. 5. The method of claim 4 where the power supply has a memory, further comprising: storing the operating parameter in the memory as a first operating value when the tank circuit is configured to operate at the first resonant frequency and the inverter is configured to operate at the first inverter frequency; and storing the operating parameter in the memory as a second operating value when the tank circuit is configured to operate at the second resonant frequency and the inverter is configured to operate at the second inverter frequency. 6. The method of claim 5 further comprising: determining whether the first operating value or the second operating value is preferable in response to the operating parameter not being within the nominal range when the inverter is operating at the first inverter frequency or the second inverter frequency; configuring the power supply to operate so as to produce either the first operating value or the second operating value. 7. The method of claim 6 further comprising: if the first operating value is preferable, storing the first operating value in the memory as an expected operating value; and if the second operating value is preferable, storing the second operating value in the memory as the expected operating value. 8. A method of operating an inductive power supply on a primary side for a load on a secondary side, the inductive power supply having a tank circuit inductively coupled to the load, the tank circuit having an adjustable resonant frequency, the inductive power supply including an inverter having an operating frequency, the inductive power supply having a sensor for detecting an operating parameter of the tank circuit, the operational parameter having a nominal range in which the power supply is operating efficiently, the method comprising: determining whether the operational parameter of the tank circuit in the inductive power supply on the primary side is within the nominal range; determining whether the operating frequency of the inverter of the inductive power supply on the primary side is between a maximum frequency and a minimum frequency; adjusting the operating frequency of the inverter of the inductive power supply on the primary side in response to determining that 1) the operating frequency of the inverter is between the maximum frequency and the minimum frequency and 2) the operational parameter of the tank circuit in the inductive power supply on the primary side is not within the nominal range; and adjusting the resonant frequency of the tank circuit of the inductive power supply on the primary side and the minimum frequency and the maximum frequency of the inverter of the inductive power supply on the primary side in response to determining that the operating frequency of the inverter is not between the maximum frequency and the minimum frequency. 9. The method of claim 8 where the tank circuit includes a variable capacitor and the adjusting resonant frequency of the tank circuit step comprises: adjusting the capacitance of the variable capacitor of the tank circuit to adjust the resonant frequency of the tank circuit. 10. The method of claim 8 where the tank circuit includes a variable inductor and the adjusting resonant frequency of the tank circuit step comprises: adjusting the inductance of the variable inductor of the tank circuit to adjust the resonant frequency of the tank circuit. 11. A contactless power supply, defining a primary side, for inductively powering a remote device, defining a secondary side, the contactless power supply comprising: a resonant tank circuit located on the primary side including at least one of a variable capacitor with a variable capacitance and a variable inductor with a variable inductance, the tank circuit having an adjustable resonant frequency as a function of the at least one of the variable capacitor and the variable inductor, said resonant circuit having a primary for transferring power to the remote device; a switching circuit located on the primary side electrically coupled to the tank circuit, the switching circuit operating at an adjustable operating frequency; a circuit sensor located on the primary side operatively coupled to the resonant tank circuit and generating a sensor output; and a controller located on the primary side electrically coupled to the circuit sensor for receiving the sensor output, the controller programmed to: (1) adjust the adjustable operating frequency of the switching circuit in response to the sensor output; and (2) adjust the adjustable resonant frequency of the tank circuit in response to the sensor output by at least one of (i) varying the capacitance of the variable capacitor of the tank circuit; and (ii) varying the variable inductance of the variable inductor of the tank circuit. 12. The contactless power supply of claim 11 where the controller adjusts the adjustable resonant frequency in response to power information from the remote device. 13. The contactless power supply of claim 11 wherein the variable capacitor includes a bank of capacitors and the capacitance of the variable capacitor is varied by a capacitance switch operatively coupled to the controller and the bank of capacitors. 14. A contactless power supply located on a primary side of an inductive coupling for providing power to a remote device located on a secondary side of the inductive coupling, the contactless power supply comprising: an inverter located on the primary side of the inductive coupling, the inverter having a duty cycle and an operating frequency; a resonant circuit located on the primary side of the inductive coupling coupled to the inverter, the resonant circuit having a resonant frequency, the resonant circuit having a primary for transferring power to the remote device; a power source located on the primary side of the inductive coupling coupled to the inverter, the power source having a rail voltage; a sensor located on the primary side of the inductive coupling operatively coupled to said resonant circuit, said sensor generating a sensor output; and a controller located on the primary side of the inductive coupling in electrical communication with said sensor, said controller programmed to: (1) vary at least one of the operating frequency of the inverter, the rail voltage of the power source, and the duty cycle of the inverter, in response to said sensor output, periodically during use; and (2) vary the resonant frequency of the resonant circuit in response to said sensor output. 15. A method of operating an inductive power supply located on a primary side of an inductive coupling for a remote device located on a secondary side of the inductive coupling, the method comprising: inductively coupling the inductive power supply located on the primary side of the inductive coupling to the remote device; sensing, in the inductive power supply located on the primary side of the inductive coupling, a characteristic of power in the inductive power supply, the sensed characteristic of power being affected by a characteristic of the remote device located on the secondary side of the inductive coupling reflected through the inductive coupling; adjusting a resonant frequency of a tank circuit located on the primary side of the inductive coupling in the inductive power supply in response to the sensed characteristic of power by at least one of (i) adjusting a capacitance of a variable capacitor of the resonant circuit; and (ii) varying a variable inductance of a variable inductor of said resonant circuit; and adjusting at least one of an operating frequency of the inductive power supply, a duty cycle of the inductive power supply, and a rail voltage of the inductive power supply located on the primary side of the inductive coupling, as a function of the sensed characteristic in the inductive power supply. 16. The method of operating an inductive power supply of claim 15 wherein the variable capacitor includes a bank of capacitors, wherein the capacitance of the variable capacitor is controllable a capacitance switch operatively coupled to the bank of capacitors.