An imagination, Is wireless power transfer possible? Is now not an imagination. In the present world, we could see various devices using the wireless charging technology which is making the user’s life more comfortable and clutter-free.
Wireless charging offers various applications, due to increased mobility and advancement running on a frequent basis in the various working field, which includes healthcare, automobile and manufacturing industries and allows numerous internet of things (IoT) devices to get power some feet away from a charger.
Wireless power transfer technology works on electro-magnetic power transfer. In that one device functions as a transmitter and other works as a receiver. The transmitter device operates by electric power from a power source which then transmits the power across the surface area to generate an electro-magnetic field accross it. Then the receiver device pulls the power from the electro-magnetic field and supplies it to the inbuilt operation section.
Both the devices (transmitter and receiver) are actually two conductors which are inductively or magnetically coupled to each other. The phenomenon of mutual induction takes place, where the current pass through the first wire and creates a changing magnetic field which induces an electromotive force (EMF) in the second wire. The electromagnetic field between two copper wires further limits the distance between a device and a charging pad.
The system has the charging pads that use:
- Tightly-coupled electromagnetic inductive charging
- Through-surface type chargers that use loosely-coupled charging that can be able to charge to a few centimetres
- Un-coupled RF charging that allows the capability to charge the device present some feet distance away.
Above said charging technique, i.e. coupled inductive and loosely-coupled charging operates on the same principle i.e. a magnetic field w.r.t time instance which induces a current in the wire.
The working is described as the oscillating magnetic field is generated by a magnetic loop antenna which will further create a current in other one or many receiver antennas. Now if some more sufficient capacitance is added to get the same resonant frequency of the loop as the value of induced current increases in the receiver device. By doing so, it will enable power transmission at greater distances between the two devices and also leads to the enhancement in efficiency. Another factor also results in the enhancement of the distance of power transfer, which is the coil size, i.e. If the size of the coil increases that will lead to more distance the charge will travel. In mobile or smartphone, the coils of wireless charging pads are of a few inches in diameter, that is why the charging distance is minimal. On the other hand with the larger diameter coil leads to more energy transferred wirelessly.
Wireless charging standards Organization:
Initially there were three wireless charging standards groups that were working on the inductive as well as resonance charging specifications: The groups are:
- The Alliance for Wireless Power (A4WP)
- Power Matters Alliance (PMA)
- Wireless Power Consortium (WPC).
Moreover, after some years 296 more members roster also included like, Apple, Google, Verizon and more electronics manufacturers.
Figure 2: Qi-compliant wireless power transfer model
Among them, the Wireless Power Consortium (WPC) created the wireless charging standard Qi (“chee“). This standard enables inductive or pad-based charging and short-distance (i.e. 1.5cm or less) electro-magnetic resonant inductive charging. Qi-compatible computing device can be charge from any Qi charging device. Not only mobile or computing devices use this standard but numerous other devices are also using the same standard and charged easily with a charging station.
There are some company with their product which are using the Qi-standard, are enlisted below:
- Apple iPhone: 8, 8 Plus, X
- Microsoft Lumia: 1520, 1020, 930, 929, 928, 920
- Nokia: 8 Sirocco
- Sony: Xperia XZ3, Xperia XZ2 Premium, Xperia XZ2
- Google Nexus: 4, 5, 6, 7
- Samsung Galaxy: Note 9, S9, S9+, Note 8, S8, S8+, S7, S7 Edge, Note 5, S6, S6 Edge
- Huawei: Mate RS Porsche Design
- LG: G7 ThinQ, V30, G6, G4, G3
- BlackBerry Priv
Wireless charging power banks
There are some power bank companies which have also adopted the Qi-technology
- Ambrane PW 11 WIRELESS Power Bank
- Haier Wireless Power Bank
- 5E Wireless Charging
- Hokonui Qi Wireless Charging Power Bank
There are enlisted some of the major automobile organisation which have also incorporated Qi-Standard into their vehicles:
Future of Wireless Charging
By observing the role and working of wireless charging in some of the significant fields in today’s scenario. We can say that the future of wireless charging is undeniable i.e. Wireless Charging: A World Without Wires.