The implementation of the Wireless Power Consortium’s (WPC’s) Qi standard1 brings wireless power to many different end applications.
The receiver (Rx) coil for each application may have different geometries and/or power requirements. Since the Rx coil is a key component in a successful and efficient design of a Qi-compliant Rx and there are many design options and trade-offs to consider, the designer must take a careful and methodical approach when realizing a solution.
This article is offered from Texas Instruments 3Q12 Analog Applications Journal (AAJ). The article written by Bill Johns, Applications Engineer, Tony Antonacci, System Engineer, and Kalyan Siddabattula, System Engineer provides the technical insight needed to realize a successful Rx-coil design.
While this article does explain quite a bit, it is clear that the impact of the several loss mechanisms is not brought out to any extent. Wireless transmission of energy for recharging portable devices will not be the most efficient way ever, it is clear.
Of course the fact that it wastes a lot more power will not take away from the "cool factor", nor will it negate the convenience of not needing to pay attention to what one is doing when connecting a charger.
In addition, the marketing weasels are very hot to make this the "next big thing" in product differentiation.
What would have made much more sense would have been a standard charging connector for all cell phones, with different sizes for the different voltages, but with all brands being forced to use the standard charging connector. Then everybody would have had the same burden, and none of the manufacturers could claim that others had an advantage.
Of course, it is too late for that to happen now, but perhaps the industry could learn.
Join our online Radio Show on Friday 11th July starting at 2:00pm Eastern, when EETimes editor of all things fun and interesting, Max Maxfield, and embedded systems expert, Jack Ganssle, will debate as to just what is, and is not, and embedded system.