WIRELESS ENERGY TRANSFER FOR MOBILE DEVICE APPLICATIONS

• US 20150303706A1
• Filed: 04/16/2015
• Published: 10/22/2015
• Est. Priority Date: 04/16/2014
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Sealy, Kylee D., Bronson, Daniel, Sharp, Bryan T.
• Granted Patent: US 9,917,479 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields

Abstract

A current sensing system and method for wireless energy transfer may include a printed circuit board, wherein the printed circuit board may include at least a first layer, a second layer, and a third layer. A loop of conductive material may be included, wherein the loop of conductive material may include a diameter D3 on the second layer. A coil of conductive material may be included, wherein the coil of conductive material may have at least 2 turns, wherein a majority of the coil of conductive material may occupy the first layer and the third layer with an outer diameter D1 and an inner diameter D2, connected through each of the first, second, and third layers. The loop of conductive material may be coupled to the coil of conductive material.

Claims

1. A current sensing system comprising:

a printed circuit board, wherein the printed circuit board includes at least a first layer, a second layer, and a third layer;

a loop of conductive material, wherein the loop of conductive material includes a diameter D3 on the second layer; and

a coil of conductive material, wherein the coil of conductive material has at least 2 turns;

wherein the coil of conductive material occupies the first layer and the third layer with an outer diameter D1 and an inner diameter D2, connected through each of the first, second, and third layers;

wherein the loop of conductive material is coupled to the coil of conductive material.

2. The system of claim 1 wherein a current value of a conductor is measured by routing the conductor through the inner diameter D2 of the coil of conductive material.

3. The system of claim 2 wherein the conductor is part of a resonator coil.

4. The system of claim 1 further comprising a parallel resonant circuit to remove harmonic content.

5. The system of claim 1 further comprising a differential amplifier with a voltage output.

6. The system of claim 5 further comprising peak detector circuitry including an operational amplifier to track a peak of the voltage output and determine a measured current value of a conductor.

7. The system of claim 1 further comprising a fourth layer proximate to the second and third layers, wherein the fourth layer includes an additional loop of conductive material coupled to at least one of the loop of conductive material and the coil of conductive material, wherein the additional circular loop of conductive material has a diameter D3 on the fourth layer.

8. The system of claim 1 wherein the coil of conductive material includes copper trace.

9. The system of claim 1 wherein the coil of conductive material is configured with at least one of a straight return and a balanced winding.

10. The system of claim 1 wherein currents with frequencies within a range of 85 kHz to 20 MHz are configured to be measured.

11. The system of claim 1 wherein the coil of conductive material has at least 15 turns.

12. A method of sensing current comprising:

driving a conductor with alternating current; and

measuring an amplitude value and phase value of the alternating current using the current sensing system of claim 1.