ECE 110/120 Honors Lab Section : Wireless Charging Cable

Zexuan Cheng - zexuanc2 - ECE 110

Patrick Shalton - shalton3 - ECE 110

Introduction

• 1. Statement of Purpose
  
  
  • • Many people use their phones while plugged into a charger. This can be harmful to the charging port on the phone as, over time, the port becomes widened and only charges when the cable is plugged in at a certain angle, which often leads to inconsistencies in charging and further deformation of the port. Additionally, this can cause deterioration and fraying of the cable itself. A wireless "dongle" and base inductor loop would allow for free use of the phone while charging without fear for damage to the phone or cord and a larger area that the phone can be both charging and used in.
  
  
  • • The transmitter circuit that we found uses an IC that cannot tell when a device is placed near it, so we decided to implement that functionality ourselves. To do this, we thought about using either an ultrasonic sensor, voice recognition module, or NFC module to take on/off commands. We decided to use an NFC module, as the range for NFC communication is very similar to the distance needed for efficient wireless charging and we can program both the phone and module to implement alerts and additional functionality.
  
       2. Background Research
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  • • Wireless charging is a relatively new way of charging electric devices. It uses electromagnetic induction, which acts like a transformer consisting of a transmitting coil and a secondary coil for receiving. It has its own pros and cons. On the bright side, the wireless charging devices don’t need actual connection between devices and power resource, so preventing the damages of the motherboard interface. On the other hand, excluding from the complicated circuits, our devices can be more agile, which allow us to use more conveniently. The downsides of wireless charging are that they have relatively poor efficiency comparing to the conventional charging. Also the wireless charging devices still cannot be completely and ideally separated from the power resource. But we are going to find a way to make our charging devices as convenient as possible

      It has its own pros and cons. On the bright side, the wireless charging devices don’t need actual connection between devices and power resource, so preventing the damages of the motherboard interface. On the other hand, excluding from the complicated circuits, our devices can be more agile, which allow us to use more conveniently. The downsides of wireless charging are that they have relatively poor efficiency comparing to the conventional charging. And the wireless charging devices still cannot be completely and ideally separated from the power resource. But we are going to find a way to make our charging devices as convenient as possible.

      
      

    • NFC, or near-field communication, is a technology that has only recently been implemented in phones (starting in 2010) and is becoming more popular with the increased interest in mobile payment. It utilizes close-range, low power radio signals to transmit data over short distances. Its uses are widespread and include RFID card readers, peer-to-peer communication, and secure transmission of data, but it also opens up a suite of personalization possibility for mobile users. This includes using readable and writable NFC tags to initiate commands and display data on phones and other devices when they are brought in proximity. Currently, we believe that NFC is an underused consumer technology that we can use to add more personalization to our phones.

      
      
      

Design Detail

1. Block Diagram / Flow Chart

2. System Overview

• Our circuit will start with the power supply and run to the magnetic sensor. If the sensor detects a strong magnetic field by it (provided by a magnet), it will switch on and start running current through the main electronic components and primary coil. The primary coil will produce a changing magnetic field at a certain frequency, which will create a voltage in the secondary coil. The two coils may be coupled through resonant inductive coupling. The voltage in the secondary coil will produce a current and charge the device. When the device is fully charged, the current will be redirected to an LED to signal that the device is finished charging.

Parts

• NFC Module
• Transmitter/Transmitter Circuit - https://www.seeedstudio.com/Qi-Wireless-Charger-Transmitter-5V%261A-p-1997.html
• Receiver with USBC/Lightning - https://www.seeedstudio.com/Qi-Wireless-Charger-Transmitter-5V%261A-p-1997.html
• Wall Adapter and MicroUSB Cable
• Arduino

Project Report

Tutorials

• https://www.instructables.com/id/Wireless-Ipod-Charger/
• http://wiki.seeedstudio.com/Qi_Wireless_Charger_Transmitter/

Possible Challenges

References

• Mearian, Lucas. “Wireless Charging Explained: What Is It and How Does It Work?” Computerworld, 31 Oct. 2017, www.computerworld.com.au/article/629365/wireless-charging-explained-what-it-how-does-it-work/?pp=2&fpid=1.
• “Inductive Charging.” Wikipedia, Wikimedia Foundation, 12 Sept. 2018, en.wikipedia.org/wiki/Inductive_charging.