Wireless Charging Technology (WCT)

By Mark Kiprotich

Since time immemorial, the technology has always advanced and it seems like it is going to sojourn advancing anytime soon. In an exertion to make life easier and much more comfortable, engineers have constantly and unceasingly designed new gadgets, equipment and machines. The electronic world has specifically technologically advanced significantly in the recent year.

Engineers and researchers developed a great interest in Wireless Power Transfer (WTP) technology, which takes advantage of magnetic resonance. The WPT device allows multiple users to charge their gadget at the same time. There are several of such devices (WTPs) in the market such as PowerMat 3X, Energizer Wireless Charger, Mobee Wireless Charger, Duracell Mygrid and Wildcharge Pad.

These gadgets utilize the fundamental principle of electrical engineering, mainly resonance coupling. The devices use resonators (transmitters and receivers) to achieve efficient wireless power transfer.

Wireless Charging for Mobile Phones
The PowerMat 3X is a radiant, svelte three position wireless charging gadget that has tried to overcome the power losses by utilizing a magnetic attraction between very receiver and each access point on every mat. The communication between the Mat and the Receiver enables the mat to deliver an exact amount of power for Wireless Charging Technology (WCT) the proper length of time so that the power transfer is efficient and safe.

Source: IT With All, 2015
Energizer Wireless Charger, is a WPT device that is founded by the Qi Technology and aims to be the next-generation charging solution for many devices. The "Qi" inductive charger is already available for mobile devices such as iPhone 3G, 3Gs, 4 and Blackberry Curve8900. The device is about 85 percent efficient and costs about $ 110.

Wireless Charging for an Automotive
Global warming and environmental pollution has necessitated the need to abandon the Internal Combustion Engines (ICEs) or even the hybrid Fuel Cell Vehicles (FCV) and go for the Electric Vehicles (EV). The EV have the advantage of minimal environmental pollution and low maintenance cost. The WCT has also been embraced in the EV and examples include Evatran, Delphi and Witricity. The Delphi Corporation has designed a power system that can wirelessly charge both the phone and an EV. Nevertherless, Evatran has a developed a Plugless Power EV Supply Equipment that enable the inductive charging for EVs. The Plugless Power EVSE delivers electrical power to the EV battery through electromagnetic induction.

Source: Ecofriendly, 2015
In layman's dialect, the inductive charging functions by isolating the two halves of an electric transformer with an airgap - one half, the Plugless Power Vehicle Adapter, is fitted on the automobile and the other half , the Plugless Power Power Pad, is installed on the base of a parking lot or a garage. When an EV fitted with the adapter drives over the Pad, the two halves are brought to close proximity (70-130mm) then the current from the electrical grid flows through the coils in the Power Pad to create magnetic fields and these fileds induce current flow in the vehicle's adapter coils by Faraday's and Lenz's laws.

The Shortcomings of WCT
Like any other system, the WCT suffers a number of limitations. The first limitation is that the price of the WCT is quite high. It is worthy to note that the price of an EV is twice the price of the ICE or FCV. Same applies to mobile phones. The other disadvantage of the WCT is the power loss factor. Generally, the cable or wire power transfer has less power losses as compared to wireless power transfer. However, there has been improvement on the efficiency by various means such as selection of optimum frequency that results to resonance and hence the maximum power transfer. Lastly, the WCT takes more time to charge a battery.