Multi-element portable wireless charging device and method

• US 9,614,396 B1
• Filed: 06/09/2016
• Issued: 04/04/2017
• Est. Priority Date: 06/09/2016
• Status: Expired due to Fees

• Current Assignee: Sultan Qaboos University
• Original Assignee: Sultan Qaboos University
• Inventors: Bait-Suwailam, Mohammed M., Al Kindi, Mohammed Nasser, Al Mahrami, Ammar Khamis, Al Dawood, Jaafar Abdullah, Al Balushi, Abdulaziz Mohammed
• Primary Examiner(s): Rodas, Richard Isla
• Assistant Examiner(s): HERNANDEZ, MANUEL J
• Application Number:
  US15/178,458
• Time in Patent Office: 299 Days
• Field of Search: 320108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

The multi-element portable wireless charging device includes a transmitter having a DC power source (battery), an oscillator connected to the battery for converting the DC to AC, a power amplifier connected to the AC output of the oscillator, and at least one flat, planar primary coil connected as a load of the power amplifier circuit. The system also includes a receiver (typically installed in the device requiring recharging) that has a flat, planar secondary coil in which an AC current is induced when placed in close proximity (1-3 cm) to the primary coil, a full-wave bridge rectifier to rectify the AC current to DC, and a voltage regulator connected to the rectifier to provide a steady DC voltage required by the charging circuit to charge the mobile device. Power is transmitted from the transmitter to the receiver by magnetic inductive coupling.

Claims

1. A multi-element portable wireless charging device, comprising:

a DC power source;

an RF oscillator circuit connected to the DC power source, the oscillator circuit having an oscillating output signal, wherein the RF oscillator circuit comprises a Colpitts oscillator;

a power amplifier circuit having an input connected to the oscillating output signal of the RF oscillator circuit and an output having a tuned circuit maintaining the power amplifier output at a frequency between 100 kHz and 210 kHz, wherein the power amplifier circuit comprises a class C amplifier circuit;

at least one flat, planar primary coil connected to the output of the amplifier circuit, the DC power source, the RF oscillator circuit, the power amplifier circuit, and the primary coil forming a transmitter;

a USB charging port circuit connected to the transmitter;

at least one receiver having;

a flat, planar secondary coil;

a full-wave bridge rectifier circuit connected to the secondary coil for rectifying an alternating current signal induced in the secondary coil; and

a voltage regulator circuit connected to the rectifier circuit for producing a regulated 5 V output, the output of the voltage regulator circuit being adapted for connection to a battery charging circuit of a mobile device in need of battery charging;

a wireless communications circuit connected to a PIC microcontroller circuit, the wireless communications circuit being adapted for establishing communications with the mobile device in need of battery charging, the PIC microcontroller being configured for signaling a relay switch to close and apply power to the RF oscillator circuit when a battery of the mobile device needs charging and for signaling the relay switch to open and disconnect power from the RF oscillator circuit when the battery of the mobile device has completed charging,

wherein power is transferred from the transmitter to the receiver by magnetic inductive coupling between the at least one primary coil and the secondary coil of the at least one receiver.

2. The multi-element portable wireless charging device according to claim 1, wherein said DC power source comprises a fully charged battery, whereby the transmitter is portable.

3. The multi-element portable wireless charging device according to claim 1, wherein said oscillator circuit comprises an inverting operational amplifier and an LC tank circuit providing feedback to the operational amplifier.

4. The multi-element portable wireless charging device according to claim 1, wherein said USB charging port circuit is adapted for receiving a USB cable connected to the mobile device and applying a charging voltage through the cable when the battery of the mobile device is too depleted to maintain wireless communications through the wireless communications circuit.

5. The multi-element portable wireless charging device according to claim 1, wherein said at least one receiver is dimensioned and configured for installation within the mobile device in need of battery charging.

6. The multi-element portable wireless charging device according to claim 1, wherein:

said power amplifier circuit comprises two power amplifiers connected in parallel;

said at least one primary coil comprises two primary coils, each of the primary coils being connected to the output of a corresponding one of the power amplifiers; and

said at least one receiver comprises two receivers;

whereby the system is capable of charging batteries in two mobile devices simultaneously.

7. The multi-element portable wireless charging device according to claim 1, further comprising:

a low-weight magnet attached to the center of said at least one primary coil; and

a second magnet attached to the center of said secondary coil.

8. The multi-element portable wireless charging device according to claim 1, wherein two receivers are oriented on the transmitter'"'"'s pad in any direction and more than two flat coils are overlapped within a housing of the transmitter.

9. A method of using the multi-element portable wireless charging device according to claim 1 to charge a battery in a mobile device, comprising the step of aligning the at least one primary coil with the secondary coil of the at least one receiver horizontally and vertically so that the coils are separated by a gap between 1 cm and 3 cm in order to ensure power transmission from the transmitter to the at least one receiver by magnetic inductive coupling.