Wireless charging: terrific idea but what's the hold-up?

29-01-2015 |   |  By Paul Whytock

Nobody wants a 'spaghetti Junction' of wires invading their space so wireless charging has to be a good idea and definitely the way forward. Industry pundits agree with that and believe the demand for such technology will grow substantially.

This view is well supported by recent statistics from research company Markets and Markets that suggests the wireless phone chargers market will be valued at almost $14billion by 2020 and will have a CAGR of over 60%.

All very positive stuff. So why is consumer acceptance of wireless technology only progressing at a snail's pace? This apparent hiatus is due to several factors. Consumers are always wary regarding safety when it comes to products that have a power function and, secondly, the continuing saga of sorting out industry standards for the different technologies continues to rumble on without a clear conclusion.

Currently, there are five wireless technologies; RF technology, inductive coupling technology, magnetic resonance technology, microwave and optical beam technology and one of the big technological hurdles to be cleared in the bid to win consumer confidence involves the question of compatibility.

Fundamentally, consumers tend to feel more confident about parting with their cash when they know the equipment they are buying will not be rendered useless by incompatibility problems. And this can only be resolved when all encompassing standards have been ratified in a form that manufacturers will be happy to adhere to.

But despite these concerns what the industry can be confident about is that the evolving wireless charging industry has numerous consumer-related application opportunities that potentially represent very lucrative profits. Industry analysts believe the increased acceptance of wireless charging for phones during the next five years could result in a globally installed user-base of approximately 170 million units.

Fundamentally the wireless charging market has been divided into some basic sectors consisting of device technology, transmission range, application and geography. Additional divisions are made for short range, mid-range and long-range transmission capability.

So given the technological and application diversification facing wireless charging phones it perhaps becomes more understandable that defining industry standards is no small task. It does nevertheless remain an undeniable imperative.

There are three standardisation organisations striving to take a leading position in the wireless charging market.

The Power Matters Alliance (PMA) was formed in 2012 and is currently working on the formalization of its industry standard.

The Wireless Power Consortium (WPC) has established the globally recognised Qi standard and there are approx 400 products that are certified as conforming to Qi. Finally, there is the Alliance for Wireless Power (A4WP) that was founded in 2012.

Ultimately it will be the task of these organisations to settle any standards battles. And the sooner the better. Consumers don't want protracted technological struggles like the one that hindered the introduction of Blu-Ray when it had to prove itself the better choice compared to HD-DVD. Predicting which standard will emerge as all-conquering may not actually be possible because each organisation is focused on different wireless charger technologies.

The standards from WPC and PMA relate to inductive charging and are defined as tightly-coupled systems. These are generally reckoned to be more efficient than the alternative loosely-coupled designs that employ resonant charging. However, as the name suggests, tightly coupled charging relies on the receiver and transmitter being positioned within a few millimetres of each other.

The advocate of resonance charging is the Alliance for Wireless Power (A4WP) and the attraction of this technology is it allows greater freedom of how units needing charging have to be positioned against the charging transmitter unit. Basically it allows greater spatial freedom. But there is a negative aspect to loosely-coupled charging. That spatial freedom decreases efficiency and there are also potential electromagnetic interference challenges that have to be resolved.

Reduced efficiency is of course important when it comes to wireless charging. It would mean longer charging times and could potential exacerbate heat dissipation problems, two things that would certainly worry consumers. It is generally accepted that tightly-coupled charging provide efficiencies higher than 70% whereas loosely-coupled manages about 60%.

Ultimately, emerging standards from the various industry bodies need to not only standardise the enormous mix of electrical and electronic specifications required for wireless charging compatibility but they need to also firmly establish precise and practical communication and safety principles.


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By Paul Whytock

Paul Whytock is European Editor for Electropages. He has reported extensively on the electronics industry in Europe, the United States and the Far East for over twenty years. Prior to entering journalism he worked as a design engineer with Ford Motor Company at locations in England, Germany, Holland and Belgium.

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