Electronic Design
A Look Ahead at Wireless Charging

A Look Ahead at Wireless Charging

Tech Editor Don Tuite reports back with his takeaways from the Wireless Power Summit in Oakland, Calif.

The start of a new year is always a good time to look at where things seem to be going. Just before Thanksgiving, I had the opportunity to attend the fourth annual Wireless Power Summit, a two-day conference held in Oakland, Calif. By my count, there were 150 or more attendees at a conference that costs a lot of money to attend. It was a pretty good mix of “suits” and engineers. The suits got to hear forecasts and updates on how wireless charging is or will be applied, and the engineers attended sessions late in the day in which university researchers addressed technical issues—which were mainly concerns about power conversion efficiency between chargers and the devices they charge.

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In a nutshell:

1. Free charging of smart devices is creeping into consumer services. The free charging lures customers in the door, and the data collected about those customers justifies the free services.

Interestingly, at the same time that we were meeting in the fancy hotel, Starbucks outlets all over the Bay Area were publicizing the availability of charging stations built into their table surfaces. There would be no monitoring of the customer’s activities, but there is a built-in handshake between chargers and smartphones that does provide some feedback about the phones. That, and data about the customer’s preferences for seating, length of stay, and so forth, are supposed to be amalgamated into general customer information that will tell the corporation about habits and preferences without breaching privacy.

2. There was a lot of focus on smartphones (of course) and wearables, which are essentially fitness devices and watches that interact with phones. I’m not sure what wearable electronics are going to do for youmaybe they can tell you when they need to be washed; maybe they can include animated graphics.

One thing about wearable tech: In general, chargeable wearables present a challenge for coil orientation. Phones have big flat surfaces and users lay them on top of other flat surfaces, so the problem is reduced to two dimensions. Charging somebody’s raincoat--the one that lights up at night, perhaps--is a lot more challenging.

3. There was some talk about wireless charging of objects in the Internet of Things (IoT), but not much, to my recollection. It was more as if people felt they had to say something about the IoT, without actually having anything to say.

4. There was a lot of interest in how wireless charging would be implemented in personal vehicles. I was reminded of a talk I heard last year at Cisco about how everybody’s car would become their personal gateway to the IoT, routing data through the most cost-effective gateways. Obviously, that would only work if driver and passenger phones stayed charged up all the time.

The big question in cars was, which approach to charging is going to dominate: Qi, PowerMat, or A4WP? One market analyst made the point that carmakers have to take “long bets”--they can’t swap tooling every year--so whatever direction they choose is going to be the standard.

5. Technical challenges are fascinating. Presently, there are two popular approaches, both near-field. The least efficient is simply to create a transformer by bringing two coils into close proximity. A step up from that is to tune the coils to resonance, a la Nikola Tesla. What’s still in the university labs involves, among other things, coupling coils between charger and the unit being charged. Essentially, energy is stored in the intermediate tuned circuit. This overcomes some of the problems of an over-large air-gap.

The technology talks went by too fast for me to get more than a taste, but here are the academics who presented and their topics:

David S. Ricketts, Associate Professor of Electrical and Computer Engineering, North Carolina State University. His presentation was an overview:  Advances in Wireless Power Transfer Research from Academia: Challenges and Opportunities.

Prof. Dr. Jenshan Lin, Professor, Department Of Electrical & Computer Engineering, University Of Florida And Chair, IEEE MTT-26 Technical Committee On Wireless Energy Transfer And Conversion:  Wireless Power Transfer: From Far Field to Near Field.

Prof. Dr. Zoya Popovic, Hudson Moore Jr. Chaired Professor at University, University Of Colorado, Boulder:  Far-field wireless powering for low-power sensors.

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