Friday, June 14, 2013

Wireless Charging


Wireless charging is the next big thing. Not only is it going to replace clumsy wired cables but it is going to unveil a whole new world of possibilities. Before we get into that, a little bit of tech gyan on how it works. Wireless charging or technically inductive charging is similar in principle to a transformer. The primary coil is in the base unit that creates an alternating electromagnetic field and the secondary winding in the portable device receives the flux and converts it back to alternating current to recharge the battery.

Continuous in-road wireless charging

One of the biggest possibilities of inductive charging is in-road wireless charging. This is similar to the power supply to trains and trams minus the overhead cables and clumsy pantographs. Primary cables are laid inside the road surface to which electricity is supplied and receivers are placed underneath electric vehicles which acts as secondary coil. This non-contact method can be used for charging as well as providing a continuous electrical power supply to vehicles where plugging-in is not convenient or possible. This is weather proof and safer also as no electrical points are exposed.
Wireless Mobile Charger
Charging an electric car takes a long time and requires expensive and bulky batteries for long ranges. A very practical application of in-road induction charging would be to lay cables throughout the lengths of highways where electric/hybrid vehicles can ply over the entire length without the need of big and expensive batteries. This is particularly very suitable for electric/hybrid buses and trucks which travel long distances on a fixed route. When used by electric cars, it can help eliminate range anxiety – one of the biggest hindrances in the popularity of electric cars. If this is coupled with green electricity, then zero carbon transportation is possible.Static chargers can be helpful at homes, parking lots or under bus stops for quick top-up.


There are a couple of challenges to be met before this technology can be put to use. First, the efficiency is lower than conductive chargers though 90% efficient wireless chargers have been developed at Utah State University. Secondly, electromagnetic interference with patients wearing pacemakers is a concern. Qualcomm Halo, a leading wireless charging developer believes there needs to be an universal set of regulations and limits to address this. Also the modes of payment by user needs to be figured out. So far, the pros of this technology does sound very tempting. The fact that stationary wireless chargers for mobile phones and electric cars are available commercially is promising enough that the day of in-road wireless chargers is not far away.

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