Wireless power for charging mobile devices

Wireless power has become a hot topic as wireless charging of mobile devices is get getting some popularity. Wireless charging isn’t something new; the technology exists since 1981 and Nikola Tesla has made first wireless power experiments over 100 years ago. Wireless charging for Qi technology is becoming the industry standard on smartphones (pushed by Wireless Power Consortium) as Nokia, HTC and some other companies use that. There is a competing AW4P wireless charging standard pushed by Samsung ja Qualcomm. And there is more standards coming. Power Matters Alliance is heavily pushing their own wireless charging standard. It seems there is going to be fight on wireless charging in near future. It seems that right now we’re in the midst of a battle between two standards for wireless charging – Qi from the Wireless Power Consortium and Power 2.0 from the Power Matters Alliance. It seems that a common Wireless Power Standard Years Off as Battle Heats Up.

As obviously useful as wireless charging is, it suffers from a Tower of Babel problem with incompatible standards and competing interests keeping it from truly going mainstream. Wireless charging continues to be a niche category until there’s a common standard. Heavyweights are backing the idea of wireless charging capabilities embedded in phones, and public charging stations are beginning to pop up. Differing standards, however, still make for a rocky adoption. Realistically there probably isn’t room for two or more standards, which do essentially the same to end user but are incompatible, so expect some technologies to disappear in the near future. Charging portable devices without needing to carry a power adapter sounds handy when we can agree on one standard. “Wireless charging continues to be a niche category until there’s a common standard,” said Daniel Hays, a consultant with PricewaterhouseCoopers. “The hassle factor is still high.”

Qi seems to be at the moment standard that gets most attention. The news that Nokia to join Qi party with wireless-charging Lumia 920 have given lots of publicity to it. Even if the Lumia isn’t a big seller, the publicity and visibility it will provide for Qi should be enough to make everyone forget there was ever an alternative, if indeed there ever was. Also some HTC phones and Nexus 4 phone use this standard. Toyota launches the world’s first wireless charging of mobile phones in the car. Toyota’s car will get wireless mobile phone charger using Qi standard.

Qi has been here for some years. Qi has been around for a while, gaining the name and logo back in 2009. The Qi standard came out of water filtration units, which needed wireless power, and has been widely endorsed but devices are still quite rare. Under the Qi specification, “low power” for inductive transfer means a draw of 0 to 5 W, and that’s where mobile device charging solutions most probably go. The system used inductive coupling between two planar coils to transfer power from the power transmitter to the power receiver. The distance between the two coils is typically 5 mm, but can be expanded to 40mm.

The Qi system uses a digital control loop where the power receiver communicates with the power transmitter and requests more or less power via backscatter modulation. Besides low-power specification up to 5 watts, there is also a medium-power specification will deliver up to 120 watts. The frequency used for Qi chargers is located between about 110 and 205 kHz for the low power Qi chargers up to 5 watts and 80-300 kHz for the medium power Qi chargers.

Method: inductive coupling between two planar coils
Frequency: 110-205 kHz (80-300 KHz)
Communication: backscatter modulation

WiPower was a technology start-up company that used the principles of inductive coupling to develop a near-field wireless energy transfer system. Qualcomm bought WiPower in 2010 and started quietly negotiating with manufacturers to get the technology embedded in their kit. Qualcomm argues that the additional range of WiPower (which can charge devices up to 45mm away) allows new possibilities. WiPower system is based on modified coreless inductive technology and dynamically adjusts power supplied by the transmitter to power demanded by the receiver without the need for control systems or communication. WiPower chargers are claimed to operate at about 60-75 percent efficiency.

Method: inductive coupling
Communication: no need for specific communication

Samsung and Qualcomm’s Alliance for Wireless Power (A4WP) promises more flexibility in wireless charging. Instead of induction, this standard will use loosely-coupled (LC) wireless power transfer (a series resonance-tuned pair of magnetically-coupled coils) to transmit power. This construction allows that the transmitter and receiver don’t have to be in direct contact, which gives more flexibility to industrial designers. This designs will support simultaneous charging of multiple devices with different power requirements. A4WP specification takes advantage of Bluetooth 4.0. The biggest downside in this design is that currently there are no products with this technology are yet on the market.

Method: series resonance-tuned pair of magnetically-coupled coils (loosely coupled)
Frequency: 6.78 MHz
Communications: Bluetooth 4.0

The Power Matters Alliance (PMA) is working on an open standard for wireless charging. A group of companies back up this initiative (including Google, AT&T, ZTE, Starbucks, ,McDonalds, PowerKiss). PMA uses inductive charging method used in Duracell’s Powermat product. It requires the transmitter and receiver be close together, placing the mobile device on the charging pad.

This is quite new alliance but it seems to get lots of backers: over the last few months, the PMA has seen a tenfold increase in membership. One very big thing is that AT&T is seeking from its handset vendors a commitment to one standard of wireless charging.

The PMA is working to advance the widespread acceptance of the wireless power paradigm in multiple sectors. PMA is intent on leading and organizing the Power 2.0 agenda to commercial realization, while working under the umbrella of the most trusted name in standards: the IEEE. Powermat is capable of delivering 5-to-50 watts of power. Powermat allows a built-in check for alignment via light and voice signals based on RFiD Handshake feature. When you place a Powermat-enabled device on one of its mats, the two exchange a “handshake” using RFID: The mat identifies the device, determines how much power it needs and transfers energy to it. Powermat operates at 277-357 kHz frequency. Once a device is fully charged, Powermat stops the electricity from flowing. But as much momentum as the PMA has achieved, it is far from clear whether it will be that bandwagon.

Power Matters Alliance (PMA)
Method: inductive charging
Frequency: 277-357 kHz
Communication: RFID

As obviously useful as wireless charging is, it suffers from a Tower of Babel problem with incompatible standards and competing interests keeping it from truly going mainstream. There are also attempts to support several standards on one product. Samsung Galaxy SIII wireless power supports both Qualcomm’s WiPower and Wireless Power Consortium Qi. The Samsung Galaxy S4 will support both PMA and Qi standards. NXP has developed a charging station, which allows you to use both the general mobile phone charging standards (as well as one rare third standard).

The technologies I mentioned are not the only ones trying to push to the market in the near future. Apple is trying to patent wireless charging, claiming its magnetic resonance tech is new and that it can do it better than anyone else. Digitoday writes that Finnish research organization VTT is planning to combine wireless power and NFC technologies. The reasearchers believe that in the future NFC devices could be made to work as way to get power into device and send power to other device cheaply. Technology is not ready yet, because today’s NFC antenna circuits are not optimized for power transfer and there is no standard that covers this kind of use yet. NFC operates within the globally available and unlicensed radio frequency ISM band of 13.56 MHz.

Wireless Power: Convenient, But Its Shortcomings Are Somewhat Sour article tells that close-proximity inductive coupling is commonly estimated to deliver 50 to 70% efficiency. That’s considerably worse efficiency that what you get with a well designed wired charger. Intel increases consumer-product power consumption 50% blog post says that a system that is 50% efficient on top of the ac-dc conversion, and pumps RF energy all over the place is far from ideal in world where some other parties try to conserve every single watt. In a world with 15 billion chargers, energy efficiency is a big deal. Based in that is makes me a little bit hard to believe the Power Matter Alliance claims that wireless charging could save a lots of power in the future. How Wireless Charging Will Keep Toxic Waste Out of Landfills article tries to describe how wireless power could be more eco-friendly, but it is hard to believe all those claims without good data. I can believe that wireless chargers can have better energy efficiency than some old chargers supplied with consumer devices, but I given the limitations wireless charging it is very hard to believe that wireless charger could ever be more efficient than well designed wired charger. But wireless charger could be well “good enough” to be acceptable.


  1. Tomi Engdahl says:

    How Wireless Charging Works in Mobile Devices

    How does it work?

    The charging station has a coil, where a high frequency alternating current is fed to it, generating a magnetic field with an alternating polarity. The close proximity of a device that is compatible, or designed to be charged wirelessly, will also have a coil inside it. Being in close proximity to the alternating magnetic field, an alternating current is induced in the coil that is in the device. This current is converted to dc that is then used to charge the battery of the device.

  2. Tomi Engdahl says:

    Daimler and Qualcomm To Develop In-Car Tech, Wireless Charging

    Car manufacturer Daimler announced a deal with mobile technology company Qualcomm to explore wireless mobile phone recharging in cars, as well as recharging electric vehicles without cables. The move is part of a push by Daimler, as well as rival carmakers BMW and Audi, to improve their status as high-tech carmakers.

    Daimler and Qualcomm to develop in-car tech, wireless charging

    Carmaker Daimler on Saturday announced a partnership with mobile technologies company Qualcomm Inc. to explore wireless recharging of mobile phones in cars as well as recharging of electric cars without cables.

    The move forms part of a broader push by Daimler, parent company of Mercedes-Benz, as well as rival German carmakers BMW and Audi to build their expertise in software and telecommunications to bolster their status as high-tech carmakers in an era when tightening emission rules force them to downsize engines, once a mainstay of profit.

    The companies are also exploring technologies that will enable customers to wirelessly charge devices such as mobile phones while driving in their car, as well as ways to enhance in-car experience through high-speed 3G/4G connectivity.

    “It’s important that we remain on the cutting edge of technology and continue to deliver unparalleled experiences to our customers,”

  3. Tomi Engdahl says:

    Research IHS believes that from 2015 will be a wireless charging breakthrough year. Wireless Number of exploiting downloading applications to increase dramatically. Development shows in the amount of equipment in support of technology.

    Last year, the wireless charging transmitter circuits sold 55 million copies. In 2018, the number will grow to nearly 1.1 billion and in 2024 up to 2.3 billion.

    Currently, progress is displayed in such a way that cell phone manufacturers flagship models of wireless charging is included

    P9025A is a single-chip solution for a receiver, which supports both PMA organization that WPC Qi charging standard.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=2891:langaton-lataaminen-lyo-lapi-tana-vuonna&catid=13&Itemid=101

  4. Tomi Engdahl says:

    Brian P. Rubin / ReadWrite:
    Wireless-charging standard groups A4WP and PMA make merger official

    The Wireless Power Merger Is Official
    Where once there were three, now two remain.

    Two of the three major wireless-charging standard groups—the Alliance for Wireless Power (A4WP) and the Power Matters Alliance (PMA)—finally announced Monday that their plans to merge are official. After over a year of discussion, PMA and A4WP are officially becoming one, leaving the Wireless Power Consortium and its Qi wireless charging platform as the sole alternative.

    While two is better than three for hardware developers trying to sort out which wireless-charging bandwagon to jump on, the combined entity has technical challenges to overcome in unifying its own efforts.

    Oh, and it needs a name, too.

    The union of these two organizations means a whole lot of tech companies coming together to form a wireless charging standard

    “We’d like to see this [organization] really be the [organization] that takes it global and the biggest companies in the world have bet on it,”

    What’s more important is that when the A4WP and PMA join forces, they’ll combine both of their wireless charging standards into one multi-mode solution for device-makers to rely on.

    Currently, PMA’s standard relies on magnetic induction, which requires devices to be placed on a charging surface for power transfer to happen.

    A4WP’s charging standard relies on resonance charging, which pumps power out at a a greater distance, meaning devices can be a foot or two away to receive power.

    The WPC’s Qi standard remains an outlier, albeit one that boasts a growing list of high-profile products with its wireless charging standard built in

    Resnick explained that this is a result of broad similarities between Qi and PMA’s inductive charging technology.

    “The chip companies who manufacture the inductive technology, they’re already doing dual-mode,” he said, adding that their similarities make it relatively easy for devices like the Galaxy S6 to support both standards.

    The new organization’s edge comes from the fact that it’ll also boast the longer-range resonant charging technology under the same umbrella.

    It’s very possible that the combined might of the PMA and A4WP could be enough to make their wireless charging stand out against the WPC’s Qi standard.

  5. Tomi Engdahl says:

    Doomed wireless chargers

    One of the many announcements at the show was that several top OEMs – Fujitsu, Foxconn, Lenovo, Logitech, and Panasonic – have signed up for the Alliance For Wireless Power, aka the A4WP aka “Rezence”. The A4WP also used the show to reveal that it plans to allow multi-device wireless charging up to 50 watts.

    That didn’t stop backers of the rival Qi wireless power standard showing off all manner of kit

    Source: http://www.theregister.co.uk/2014/06/06/the_strippers_unicorn_computers_and_martian_watches_of_computex/?page=3

  6. Tomi Engdahl says:

    Your Qi charger will soon support 15W fast charging

    Wireless charging is about to become just as capable as wired charging.

    An update to the Qi charging spec has been announced by the Wireless Power Consortium, and it’s all about more power and backwards compatibility. Qi chargers will soon be able to fully utilize 15W charging device, more commonly known as Quick Charge 2.0 chargers. Qi platters will be able to pass the power to devices that support this new wireless fast charging spec, which will effectively make it so wireless charging will be just as capable of getting your device from 0 to 60 in 30 minutes as your regular charger.

    Fast charging Qi platters is an exciting development in the wireless charging conversation, and backwards compatibility means all of your existing Qi hardware will support this new capability as soon as your have a device that supports the new feature. While many Android phones already support a variant of Quick Charge 2.0, it’s not yet clear when we’ll see a device support this updated spec. It’s unlikely this is something that can be activated with a firmware update, rather something you’ll be able to look forward to on your next smartphone.

  7. Tomi Engdahl says:

    Wireless Charging Awareness Surging

    Consumers are becoming more aware of wireless charging technology, thanks in large part to its inclusion in recent high-profile products like the Samsung Galaxy S6 and the Apple Watch.

    According to a recent survey conducted by market research firm IHS Inc., 76% of consumers in the U.S., U.K. and China are now aware of wireless charging technology—more than double the percentage of consumers who indicated they were aware of the technology a year ago.

    According to IHS estimates, shipments of wireless power receivers in mobile handsets alone are forecast to top 120 million units in 2015. A large chunk of those receivers are expected to ship in Samsung’s Galaxy S6 and Galaxy S6 Edge smartphones.

    In wearable electronics, some 20 million wireless charging receivers are expected to ship this year, according to IHS. More than 14 million of this are expected to come from shipments of the Apple Watch alone, according to the firm.

    “This is not just good news for the likes of Samsung,” Green said. “This is good news for anyone involved in wireless charging. The whole point is that people are starting to hear about wireless charging, starting to accept it and starting to see the need for that use case.”

    Three’s a crowd
    But while consumers on the whole may be more aware of wireless charging technology, the technology itself is still somewhat fragmented based on the fact that three competing alliances—the Qi Wireless Power Technology Alliance, the Alliance for Wireless Power (A4WP) and the Power Matters Alliance (PMA)—have been pushing competing technologies.

    While A4WP and PMA agreed June 1 to merge, there are still two different technologies involved, Green said. The two groups will get together and join under one name, Green said, but “the two technologies are not compatible because they work on completely different frequencies.”

    “Really, this comes down to the consumers,” Green said. “The consumer doesn’t care what kind of technology is used. The consumer just wants wireless charging that will work with everything out there.”’

  8. Tomi Engdahl says:

    Wireless Power Transfer Using Capacitive Plates

    It seems like wireless power transfer is all the rage these days. There’s wireless charging mats, special battery packs, heck, even some phones have it built in! And they all use inductive coils to transfer the power — but what if there was another way? Coils of copper wire aren’t always that easy to fit inside of a product…

    As an experiment, [Josh Levine] decided to try making a proof of concept for capacitive power transfer.

    He first demonstrates inductive power transfer using two coils of copper wire to power up an LED. The charging coil is supplied with 15V peak-to-peak at 1MHz which is a fairly typical value for inductive charging.

    It works using the concept of capacitive coupling, or electrostatic induction. The main reason it isn’t used as widely as inductive power transfer is because it requires higher voltages to transmit significant power

    Plates vs Coils – An alternative approach to wireless power transmission

  9. Tomi Engdahl says:

    Wood-fired LED lantern converts waste heat into light & power

    Don’t let the Stove Lite LED lantern’s appearance deceive you. Beneath those old-timey looks, lies a thermo-electric generator (TEG), which uses the Seebeck effect to convert the heat of your wood stove into enough energy to run its LED lamp.

    With a price tag of $149 ($199 for the Pro model), Stove Lite may be too pricey for use as a toy. But for serious campers, off-gridders and preppers this solidly-built unit can be a life-saver when cloudy skies or other circumstances render solar-electric systems useless.

    In addition to providing a light that’s bright enough to read by, this wood-powered LED lamp has a USB jack which allows it to charge a mobile phone.

  10. Tomi Engdahl says:

    UK to trial ‘electric highways’ to charge car batteries on the road
    Using ‘dynamic wireless power transfer’ technologies

    THE UK GOVERNMENT HAS ANNOUNCED plans to trial ‘electric highways’, an initiative that will allow electric car owners to travel long distances without needing to stop and charge the car’s battery.

    Using ‘dynamic wireless power transfer’ technologies, the off-road trials will be the first of their kind in the country and will test how the technology could work safely and effectively on UK motorways and major A roads.

    The trials are expected to begin later this year and last 18 months

    Highways England chief highways engineer Mike Wilson said that the off-road trials of wireless power technology will help to create a more sustainable road network for England, “opening up new opportunities for businesses that transport goods across the country”.

    Highways England will also install plug-in charging points every 20 miles on the motorway network as part of the government’s Road Investment Strategy to promote the use of electric vehicles.

    The government launched an initiative last month to fund £20m in research and development for driverless vehicles which will look to integrate the vehicles into society.

  11. Tomi Engdahl says:

    England To Test “Electric Motorways”

    Highways England plans to test under-road wireless charging equipment that could be buried beneath motorways to top-up cars as they drive. Charge-as-you-drive technologies have already been used in the South Korean town of Gumi. The town has a 12km (7.5 miles) route that allows buses to be charged as they drive over it.

    The trials will involve fitting vehicles with wireless technology and testing the equipment, installed underneath the road, to replicate motorway conditions. Full details of the trials will be publicised when a successful contractor has been appointed.

    England to test charge-as-you-drive ‘electric motorways’

    The government agency has announced plans to test wireless power-transfer tech that it hopes to build under the country’s motorways and major A roads.

    “What has been committed to is that by 2016 or 2017 we will hold off-road trials – in other words not on a public road,” Stuart Thompson, a spokesman for Highways England, told the BBC.

    “It’s still very early days. Where exactly the trials will be has yet to be determined.”

    Highway England says full details will be publicised once a contractor has been appointed.

    Even if the plan ultimately comes to naught, Highways England is also committed to installing plug-in charging points every 20 miles (32.1km) on its motorway network over the “longer-term”.

    South Korean tests

    Charge-as-you-drive technologies have already been pioneered elsewhere.

    In 2013, the South Korean town of Gumi switched on a 12km (7.5 miles) route that allows buses with compatible equipment to be charged as they drive over it.

    It works by a process called Shaped Magnetic Field In Resonance.

  12. Tomi Engdahl says:

    Static Electricity Aims To Power Wearable Devices

    Most people encounter the buildup and discharge of static electricity as an unwelcome shock when touching a metal doorknob after walking across a carpeted floor or sliding across a car seat. Those of us in the semiconductor industry, though, are very familiar with the havoc that can be caused by a stray ESD pulse. ESD causes more than one-third of integrated circuit field failures, showing up as leakage, short circuits, burnout, contact damage, gate oxide rupture, and resistor-metal interface damage. As feature sizes shrink, the problem is only getting worse.

    Measures to protect against ESD in electronic equipment include on-chip ESD structures at I/O and Vdd pins, and external devices such as zener diodes and metal oxide varistors (MOVs).

    The cause of electrostatic buildup is the triboelectric effect: material becomes electrically charged after it contacts a different material through friction.

    It’s believed that after two different materials come into contact, a chemical bond is formed between some parts of the two surfaces, called adhesion, and charges move from one material to the other to equalize their electrochemical potential.

    A triboelectric nanogenerator (TENG) is a device used to convert mechanical energy into electricity using nanotechnology

    Wearables and triboelectric nanogenerators

    Wearable electronic devices such as fitness bands, medical monitoring systems, and watches have given rise to a number of techniques for supplementing their limited battery life. Energy harvesting is one such approach, converting ambient energy into electric energy utilizing such devices as onboard solar cells and piezoelectric generators. TENGs are another

    Researchers at the Georgia Institute of Technology are developing TENGs with a goal of powering small electronics for wearable devices. Using four different modes of operation, they’ve harvested energy from a range of sources such as body motion, fabrics, vibrations from human walking, hand pressing, a shoe insole, vibration of a string or tree branch, machine vibration, elastic energy in a sponge structure, and sound waves in air and water.

  13. Tomi Engdahl says:

    Wireless Fast-Charge Tech Enables a World of Possibilities

    15-watt Qi extension is ready and waiting for mobile phone users, designers, and service providers.

    Wireless charging has captured the imagination of mobile phone users, designers, and service providers. Now, with the introduction of the 15-watt extension to the Qi specification, a new world of products and capabilities has opened up.

    While previously the benefits of wireless charging had been limited to charging mobile phones at five watts (on par with typical wired charging), the convenience and reliability of wireless charging has made it a “must-have” in many smartphone feature check-lists. Recent announcements from IKEA and Samsung have hastened the adoption of this convenient charging technology.

    The first new benefit of the increased power is the ability of mobile phone manufacturers and after-market accessory makers to offer wireless fast-charge capability.

    Wireless Fast-Charge Tech Enables a World of Possibilities

    The first new benefit of the increased power is the ability of mobile phone manufacturers and after-market accessory makers to offer wireless fast-charge capability. This new technology goes by various names: Quick Charge 2 from Qualcomm, Adaptive Fast Charging, from Samsung, TurboPower from Motorola, and BoostMaster from Asus. What these charging systems all have in common is that they can take advantage of 15W sources like USB-3 (5V/3A) and new 9V/1.67A chargers.

    How fast is this new charging technology? Up to 75% faster than conventional charging. Qualcomm conducted a test that compared three charging approaches. The phones all used a 3300mAh battery and charged for 30 minutes. Following are the results:

    from 0% to 60% with Quick Charge 2.0 (9 volt/1.67 amp, 15W)
    from 0 to 30% with Quick Charge 1.0 (5 volt/2 amp, 10W)
    from 0% to 12% with a conventional charger (5 volt/1 amp 5W)

    The latest Qi specification enables device manufacturers to extend this speed to wireless charging. In addition, the 15W extension supports the ability to wirelessly charge tablet computers at rates similar to wired charging. Asus tablets come with 10-watt chargers and Apple iPads come with 12W chargers. That means that these digital marvels can also take advantage of wireless charging without any charging speed tradeoffs.

  14. Tomi Engdahl says:

    Wireless Power Receiver IC

    ROHM features the BD57011GWL, an addition to its wireless charging ICs line. The BD57011GWL is integrated with a fully-synchronous rectifier circuit in low impedance FETs, Qi compliant packet controller, adjustable low dropout, as well as open drain output terminal to communicate the power transmitter by amplitude modulation. The device is designed to be compatible with 5W power mobile application based on WPC version 1.1.

    Wireless Power Receiver IC – BD57011GWL (New)

  15. Tomi Engdahl says:

    Static Electricity Aims To Power Wearable Devices

    Most people encounter the buildup and discharge of static electricity as an unwelcome shock when touching a metal doorknob after walking across a carpeted floor or sliding across a car seat. Those of us in the semiconductor industry, though, are very familiar with the havoc that can be caused by a stray ESD pulse. ESD causes more than one-third of integrated circuit field failures, showing up as leakage, short circuits, burnout, contact damage, gate oxide rupture, and resistor-metal interface damage. As feature sizes shrink, the problem is only getting worse.

    Wearables and triboelectric nanogenerators

    Wearable electronic devices such as fitness bands, medical monitoring systems, and watches have given rise to a number of techniques for supplementing their limited battery life. Energy harvesting is one such approach, converting ambient energy into electric energy utilizing such devices as onboard solar cells and piezoelectric generators. TENGs are another

    Researchers at the Georgia Institute of Technology are developing TENGs with a goal of powering small electronics for wearable devices. Using four different modes of operation, they’ve harvested energy from a range of sources such as body motion, fabrics, vibrations from human walking, hand pressing, a shoe insole, vibration of a string or tree branch, machine vibration, elastic energy in a sponge structure, and sound waves in air and water.

    Researchers in Korea have also reported on a fully flexible, foldable wearable TENG; both a silver-coated textile and polydimethylsiloxane (PDMS) nanopatterns based on ZnO nanorod arrays on an silver-coated textile template were used as active triboelectric materials. With a four-layer stacked TENG, the team managed to obtain 170V and 120uA output. No significant difference in performance was observed over 12,000 compression cycles.

    Practical applications

    The Korean researchers used their technology to power LEDs, an LCD display, and a keyless vehicle entry system. But so-called “smart clothes” are already making their appearance, from Katy Perry’s LED-lit dress to smart soldier uniforms; according to Gartner, they’re predicted to surpass smartwatches and fitness bands to become the biggest wearables sector by next year, with 26 million smart garments expected to be shipped in 2016, up from 0.01 million in 2013.

  16. Tomi Engdahl says:

    Wireless Charging Visits The Hospital

    NEW YORK – Wireless charging is making its way into hospitals with the goal of eliminating power issues in everything from surgical tools to defibrillators. Medical device and component manufacturer Greatbatch has partnered with wireless charging company Witricity to create high-performance wireless charging systems for medical devices.

    “You might have to change the battery pack [of a surgical tool during an operation], which is a pretty complex process because they have to be sanitized and sterilized,” Witricity sales engineer Colin McCarthy told EE Times. “With wireless power you could just be putting a tool down on a wireless power tray – it really streamlines the process, and surgery, and eliminates the need to swap out the battery packs.”

    Medical devices and the clinicians who use them will benefit from the ability to charge at a distance, as well as the ability to charge through non-metallic materials. Designers will be able “to remove contacts and create closed systems that charge batteries through completely sealed cases, easing sterilization, reducing maintenance, and increasing reliability and availability for these critical tools.”

    While devices like a hearing aide require a small amount of power, a medical defibrillator is more power-hungry. Witricity and Greatbatch’s partnership will focus on technology for 5-100 Watts. No substantial charging architecture redesign is necessary for higher-order devices, McCarthy said.

  17. Tomi Engdahl says:

    Equipment wireless charging is convenient for the user, but the device designer, the main concern has been that one to design complex counter technology. Integrated Device Technology now says removing the barriers to the way that wireless charging is easily integrated into all types of equipment.

    The company says the two have developed a plug-and-play -type manufacturing development platform, which can be implemented so charging station than the receiving device can easily, quickly and inexpensively. IDT’s, the designer can charge the connected devices with just a few hours.

    Reference Platforms support the Qi charging technology.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=3239:idt-langaton-lataaminen-tulee-massoille&catid=13&Itemid=101

  18. Tomi Engdahl says:

    A single chip supports all wireless charging

    Semtech has introduced wireless charging transmitter and receiver circuits, which support all three major charging standard. TS8K series circuits can be implemented as wireless charging Qi, PMA as A4WP techniques.

    Semtechin TS80000 transmitter and receiver TS8100 can be implemented in a wireless downloading a wide variety of consumer electronics devices from smartphones to industrial equipment and various embedded solutions.

    At its lowest charging power is a hundred milliwatts, the highest it stretches up to hundred watts

    Source: http://etn.fi/index.php?option=com_content&view=article&id=3410:yksi-ainoa-piiri-tukee-kaikkea-langatonta-latausta&catid=13&Itemid=101

  19. Tomi Engdahl says:

    In 2020, the market is already nearly a billion devices which can be charged wirelessly.

    This market is served three main technologies: Qi, PMA, A4WP (WiPower)

    Qi technology is in a clear market leader position.
    Qi-charging equipment is estimated to be in five years from now sold 713 million.

    PMA organization Powermat and Rezence technology has been then sold up to 213 million.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=3427:qi-johtaa-langattomassa-lataamisessa&catid=13&Itemid=101

  20. Tomi Engdahl says:

    8 alternative ways to power a laptop

    In this roundup, we look at some unusual alternative solutions laptop users have devised to power or charge their devices without the advantage of using an electrical socket.
    Sponsor video, mouseover for sound

    Car battery
    Solar charging kit
    Portable wind turbines
    Micro hydroelectric power plants
    Bicycle gears
    Utilize heat sources
    Chemical alternative
    Hand crank generators
    Bonus: Power extenders

  21. Tomi Engdahl says:

    The Curious Case of Ultrasonic Power Transfer

    The future is wireless power, or so say a thousand press releases in my spam folder, and with very few exceptions every single system of wireless power delivery has fallen flat on its face. Except for a few niche cases – RFID tags, Wacom tablets and the S Pen, and the Qi inductive power mats for cell phones – the future of wireless power hardly looks bright, and in some cases seems downright dangerous. No one seems to grasp that wireless power transfer is much more inefficient than using a wire, and the inverse square law only makes everything worse.

    Now there’s a new wireless power technology that’s a strange mix of running in stealth mode and sending press releases to every tech outlet on the planet. It’s called uBeam. This company says it will deliver wireless power to the world, but it’s not doing it with giant Tesla-inspired towers of power, radios beamed directly at devices, induction, magnetic resonance, or even light. uBeam transmits power via sound, specifically high intensity ultrasound. uBeam has never demonstrated a prototype, has never released any technical specs

    The core technology, and the core criticism of uBeam is that it uses sound to transmit power. All speakers turn power into sound, and microphones operate on the reverse principle

    In the TechCrunch technical teardown of uBeam, we get a small glimpse of what it takes to transmit power via ultrasound.

    This ultrasonic transmitter is mounted on a room’s wall, converts data and energy into ultrasound, and broadcasts it directly to devices requesting power. This includes cell phones, tablets, laptops, appliances. Of course, all of these devices will be equipped with ultrasonic power receivers, all based on uBeam IP. The promise of beamed wireless power is deafening, and if you’re an investor putting this technology in millions of devices sounds like a great idea

    Of course uBeam and its investors contend the technology is safe and even innocuous, but is it? I’m completely unable to find any media that will report on the frequency or intensity of the ultrasound used in uBeam.

    uBeam will transmit at about 120 kHz, with an intensity of about 155dB. To put the frequency in perspective, humans can hear up to about 20kHz, dogs up to about 60kHz, cats up to about 80kHz, and bats up to about 115kHz.

    The difference between the intensity of uBeam and OSHA guidelines is not small; it’s only 10dB. uBeam operates at 155dB and OSHA guidelines have a limit at 145dB.

    uBeam is actually 10 times louder than OSHA guidelines, and a 2005 review of ultrasound exposure limits recommended, “sound pressure levels should be less than 110 dB above 25 kHz, regardless of the exposure duration, to prevent the undesirable subjective effects of ultrasound.”

    This is the fundamental problem of uBeam.

    The incredible attenuation of ultrasonics is the nearly insurmountable problem of uBeam, but luckily the patents tell us how the uBeam team plans to combat it. They’re using dozens of power transmitters per location; a transmitter every two feet, blaring ultrasonics.

    Unlike [georgesmith]’s teardown of uBeam, we’re going to stop short of calling it a fraud. It has not been demonstrated to the public, and although it is impractical that does not make it impossible.



    uBeam Finally Reveals The Secret Of How Its Wireless Charging Phone Case Works Safely

    Access to some of the secret details and research unveiled today convinced top investors to fund uBeam with $23.4 million. Those include Andreessen Horowitz, Founders Fund, Upfront Ventues, Troy Carter’s AFSquare, Ludlow Ventures, CrunchFund (disclosure: run by TechCrunch’s founder), Marissa Mayer, Mark Cuban, Ellen Levy, and Katie Jacobs Stanton.

    The first release of uBeam’s technology will come in the form of a phone charging case, however it also plans to power hearing aids, tablets, sensors, light bulbs, computers, and flat screen TVs. The 20-person uBeam team has filed 30 patents on all of its technologies, but is still keeping some technical details such as the acoustic intensities involved under wraps.

    How any of this could work powerfully enough to charge a device without being dangerous to humans or pets was the main point of contention regarding uBeam until today. But Perry explains that uBeams waves can’t be heard by humans, dogs, or most mammals, and does not harm living tissue or cause problems like cancer, radiation sickness, or genetic effects even with prolonged exposure.

    As for safety, uBeam’s waves stop transmitting if they’re obstructed from a receiver by something like a human body, the waves can hardly penetrate skin, and even if they did they wouldn’t hurt us.

    uBeam’s waves do not interfere with existing communication systems or electronics, so it could be used in aircraft, cars, offices, or hospitals. uBeam meets the FCC, UL, and other government regulatory requirements for electronic devices.

    The next step will be for uBeam to release a publicly testable prototype ahead of the consumer launch of its phone charging case.

    But for any of this to work, uBeam will also need to release the transmitters. It’s unclear if at first it will sell those as well.

  22. Tomi Engdahl says:

    Ultrasonic Power Transfer Investigated Using Data From uBeam Patent Filings

    Transmitting power through the air using sound above the range of human hearing: that’s the gist of ultrasonic power transfer. The promise is that you can sit in a coffee shop and use your phone like normal while it’s recharged by invisible waves of energy. That’s a future we all want — and one that uBeam has been promoting, but hasn’t backed it up with proof.

    Ultrasonic Power Transfer: uBeam’s Curious Engineering

  23. Tomi Engdahl says:

    End in sight for wireless power standards war as field shrinks to two
    Airfuel Alliance tries to chip away at Wireless Power Consortium

    The battle for wireless power supremacy is now a straight fight between two groups following the merger of the Alliance for Wireless Power (A4WP) and the Power Matters Alliance (PMA) into the Airfuel Alliance.

    “AirFuel technology is the next step in fast-tracking the commercialization of wirelessly charged products,” said Ron Resnick, president of AirFuel Alliance. “We embrace a new, inclusive ideal of wireless charging and those member companies within AirFuel Alliance are energized towards bringing wireless power products to consumers globally.”

    The merger, announced in February last year, is now complete but there is still work to be done in folding the two different wireless power standards into one.

    The magnetic inductive and resonance technology used by PMA charges one device at a time while it is close to the charging pad; A4WP’s Rezence magnetic resonance standard can power multiple devices from a single nearby power pad.

    Intel is a big investor in PMA

    “We need to eliminate the, on average, six cables that each of us carry every day,” he said. “We are going to make wireless technology ubiquitous with Rezence, be it wearable, tablet, phone or PC, all with the same technology.”

    “It certainly implies that new products will have ability to be loosely and closely charged but there are a number of really significant technology differences between PMA and A4WP’s approach and one has to question if they can merge into one standard.”

    Even if this is possible, particularly in a way that ensures backward compatibility with existing PMA and A4WP hardware, Perzow said that the Airfuel Alliance has one major disadvantage – very few people are using it.

    Intel’s support is going to be vital to the Airfuel Alliance’s plans for wireless charging domination

    So what about the competition? The Airfuel Alliance is going up against the Wireless Power Consortium’s (WPC) Qi (pronounced chee) standard, which uses magnetic induction and resonant modes to provide contactless and close-contact charging.

  24. Tomi Engdahl says:

    Former wireless charging rivals join forces as new AirFuel Alliance

    The world of wireless charging has been split, over the past few years, between three major groups. That’s changed today, as two of the three organizations — the Alliance for Wireless Power and the Power Matters Alliance — have merged, forming the new AirFuel Alliance. The new group, which counts 195 member companies from AT&T to Starbucks, will use its branding on compatible devices.

    The two organizations announced their intentions to merge earlier this year, having previously agreed to cosy up to each other and share technology back in February 2014.

    The move pits the newly minted AirFuel Alliance against the single remaining competitor, the Wireless Power Consortium, but it won’t be an easy battle to win. The WPC champions the Qi charging standard, used by a number of existing wireless chargers, built into some Ikea furniture, and used inside Microsoft’s flashy Nokia-branded charging ring released earlier this year.

    Most major tech corporations, including Microsoft, Samsung, and Qualcomm, have played all the sides of the wireless charging fight so far, joining both the WPC and the two groups that now make up the AirFuel Alliance. It makes sense for major firms to wait and they see who comes out on top

  25. Tomi Engdahl says:

    Garrett Reim / Los Angeles Business Journal:
    After Theranos debacle, wireless charging startup uBeam faces new skepticism from experts

    Skeptics Zap Wireless Charging

    Meredith Perry has bold ideas.

    For starters, there’s her notion to replace intercity car commuting with rides on small personal blimps. Then there’s her idea to mix shampoo with a material used to waterproof electronics, so that you don’t need an umbrella when it rains.

    But perhaps the boldest – and most controversial – is Perry’s attempt to wirelessly charge electronics, such as cellphones, using ultrasonic waves sent through the air.

    That idea is being tackled by the 26-year-old’s Santa Monica startup, uBeam Inc., which has raised millions in funding from a number of big-time venture capitalists, including Menlo Park’s Andreesen Horowitz, Santa Monica’s Upfront Ventures, Peter Thiel’s Founder’s Fund as well as billionaire Mark Cuban and Yahoo Inc. Chief Executive Marissa Mayer.

    However, despite being lauded as the next big thing in energy technology, the feasibility of uBeam’s plan is increasingly plagued by skepticism.

    Converting ultrasonic waves into electrical energy is rudimentarily possible – and indeed not novel – experts say, but absent a technological breakthrough, they are doubtful it can perform as uBeam claims.

    “It seems like an ungodly inefficient way to transmit energy,” said Leonard Bond, a physicist and professor of aerospace engineering at Iowa State University, who noted nothing could be deemed impossible until uBeam showed a working cellphone prototype, which it has not done. “Maybe these guys get an amazing award for having done something, but I’m not convinced yet.”

    Despite such obstacles, uBeam has raised $23.2 million from investors.

    Unfortunately for uBeam, it is now working in the shadow of the recent Theranos Inc. debacle, and rightly or wrongly is being compared to it.

    Josh Constine / TechCrunch:
    uBeam answers new skepticism with a short list of “facts” about its technology, but no actual public demonstration of phone charging — uBeam Declassifies Secrets To Try To Prove Wireless Power Is Possible — It must violate the laws of physics. It must be dangerous.

    uBeam Declassifies Secrets To Try To Prove Wireless Power Is Possible

    It must violate the laws of physics. It must be dangerous. It must be impossible. This is what critics have concluded despite not actually knowing the details behind uBeam’s wireless power technology. So rather than let the rumors swirl, today uBeam revealed a bunch of details about how far, how fast, and just plain how it can charge a phone without wires.

    “People are saying that investing [$23.4 million] into uBeam is everything wrong with Silicon Valley” uBeam co-founder and CEO Meredith Perry tells me, referencing her startup’s big name investors.

    “But everything else out there is apps and social photo sharing stuff” Perry contends. “We’re building something real. We’re building something that’s insanely difficult. So difficult people think that we’re frauds.”

    Skepticism is important when it comes to hard science startups.

    For an overview of uBeam’s ultrasound wireless power, read this deep dive. But essentially, transmitters on a room’s walls track devices with uBeam receivers and send inaudibly high-pitched ultrasound beams at them. The receiver converts the vibrations of the sound into electricity, which charges a connected device.

    Now, here are some facts about uBeam that people have asked about for years, but have never be published until now:

    uBeam has developed a high-powered air-coupled ultrasonic transducer to transmit and receive sound waves at a single frequency within the range of 45kHz to 75kHz with an output of 145dB to 155dB (or 316 W/m2 – 3kW/m2)
    uBeam can charge multiple devices simultaneously within a range of up to a 4 meter radius from a single transmitter
    uBeam is designed to deliver a minimum of 1.5 watts of electricity to smartphones, or enough to keep a phone from losing battery life even when being heavily used. Depending on the number of devices being charged simultaneously by a single transmitter, and depending on the distance of those devices to the transmitter, uBeam could charge devices at comparable rates to a wire, or faster.
    uBeam has 30-plus filed patents and 6 issued ones. At the core of its technology is the transducer the company invented, which it believes can deliver more power at the right frequency than any other.
    The patents also cover technologies including its ultrasonic phased array transmitter that includes thousands of individually addressable and controllable elements, its beamforming algorithms that can shape and steer multiple beams to multiple moving devices, and the receiver that can harvest acoustic power from these beams coming in from multiple angles.
    At launch, uBeam plans to both sell its transmitters and work with partners to install them in public places like restaurants, hotels, or cafes. It will also both sell the receiver phone cases and work with partners to loan them out to patrons of places with transmitters installed.

    uBeam Finally Reveals The Secret Of How Its Wireless Charging Phone Case Works Safely

    How uBeam Is Legal

    uBeam’s waves do not interfere with existing communication systems or electronics, so it could be used in aircraft, cars, offices, or hospitals. uBeam meets the FCC, UL, and other government regulatory requirements for electronic devices.

    Investors in uBeam demanded third-party safety and regulatory requirement audits, and were satisfied with the results. They wouldn’t have put in money otherwise.

    Finally, uBeam believes its ultrasound technology works much better than the two other forms of wireless charging: induction, which requires an inconvenient physical connection like the Apple Watch, or magnetic resonance, which requires huge transmitters and receivers that aren’t viable for charging phones and other small devices wirelessly.

  26. Tomi Engdahl says:

    Mobile Qi download speeds up significantly

    With medium power definitions charging efficiency rises to 15 watts. At the same time determinations were added to better function for detecting foreign objects, allowing, for example, the charging platform Guests metal objects are identified before the start of the charging process. Such an object could cause overheating

    ROHM says the launch of certified during the BD57015GWL transmitter circuit production in December.

    Research IHS According to the current year will be wireless charging breakthrough year. Wireless Number of exploiting downloading applications has increased dramatically. Last year, the wireless charging transmitter circuits sold 55 million copies. In 2018, the number will grow to nearly 1.1 billion and in 2024 up to 2.3 billion, IHS predicts.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=3619:kannykan-qi-lataus-nopeutuu-selvasti&catid=13&Itemid=101

  27. Tomi Engdahl says:

    Wireless Charging begins to be more expensive smartphones as a standard feature, but the development of technology will take it as soon on the tablets.

    Toshiba Electronics praises to introduce its first 15-watt power charging circuit that is compatible with the WPC-organization, ie, the Wireless Power Consortium Qi technology with the 1.2 version.

    TC7766WBG-circuit is Toshiba’s new circuit is packaged in 2.4 x 3.67mm WCSP-housing.
    The output voltage is adjustable 5-14 volts.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=3643:tabletti-ladataan-pian-langattomasti&catid=13&Itemid=101

  28. Tomi Engdahl says:

    Wireless charging is a hot topic with a broad appeal to smartphone users, EV owners and operators of industrial machines and equipment.

    Mitsubishi Electric Engineering came to the Embedded Technology show to demonstrate the company’s high-frequency power supply technology — essential to wireless charging for wide-ranging applications.

    Mitsubishi Electric’s converter — small enough to fit on the palm of your hand — has achieved 1kW power output at 6.78 MHz high frequency, while maintaining conversion efficiency at 95 percent.

    Source: http://www.eetimes.com/document.asp?doc_id=1328314&page_number=3

  29. Tomi Engdahl says:

    Wireless power enabling new applications: Wireless power is gaining in popularity and will find more applications as it is able to move to higher frequencies in the ISM bands of 6.78 MHz and 13.56 MHz in which resonant systems give high spatial freedom with excellent efficiencies. Silicon MOSFETs can’t do the job, but evolving GaN power elements will bring this technology to new heights.

    Source: http://www.edn.com/design/power-management/4440927/Software-defined-power-brings-to-bear-critical-need-in-modern-power-systems?_mc=NL_EDN_EDT_EDN_today_20151214&cid=NL_EDN_EDT_EDN_today_20151214&elq=de550d8a51b040df8e8729ce609593e5&elqCampaignId=26138&elqaid=29893&elqat=1&elqTrackId=baa4e5c846314e5a8ff25f8993ccb0f9

  30. Tomi Engdahl says:

    Garrett Reim / Los Angeles Business Journal:
    Ultrasound wireless charging startup uBeam, backed by a16z, Marissa Mayer, Founders Fund, others, closes $2.6M of $4.7M goal on crowdfunding platform OurCrowd

    Maker of Wireless Charger Losing Investment Power?

    Wireless energy startup uBeam Inc. of Santa Monica seems to be raising its financing in reverse order.

    Crowdfunding is usually done by very early stage companies. But uBeam, founded by 26-year-old Chief Executive Meredith Perry, recently closed a $2.6 million crowdfunded round after already raising tens of millions from prominent angel investors and venture capital firms over the past few years.

    Enthusiasm for uBeam was sky high during its first three years of existence

    “I’m shocked they are going after equity crowdfunding after brining in Andreessen Horowitz,” said Patrick Henry, professor of clinical entrepreneurship at USC’s Marshall School of Business. “It almost feels like it’s desperation.”

    UBeam’s crowdfunding efforts have so far raised $2.6 million of its $4.7 million target, according to a filing with the Securities and Exchange Commission. That amount was raised from 95 investors, who each invested a minimum of $10,000. The crowdfunding effort began in July and is being facilitated by crowdfunding platform OurCrowd of Jerusalem.

  31. Tomi Engdahl says:

    Take A Teardown Look inside Qi inductive wireless chargers

  32. Tomi Engdahl says:

    Ukrainian startup XE claims to have solved long-range wireless charging. The wireless power delivery tech uses the same principle as a crystal radio. The productised version of the technology will consist of a base charging station of about 15×15×40cm and a 3mm thick smartphone case. It’s claimed to be able to transfer electricity simultaneously to up to four devices that are up to five metres (16ft) away.

    Source: http://arstechnica.co.uk/business/2015/12/europes-top-tech-news-december-2015/

    More: http://arstechnica.co.uk/information-technology/2015/12/ukrainian-startup-xe-claims-to-have-solved-wireless-charging/

  33. Tomi Engdahl says:

    Wireless charging for electric vehicles

    “Wireless charger”. “Electric vehicles”. Two concepts that are much talked about. Putting them together in a single sentence, as in “let me hook up my electric vehicle to my wireless charger?” Not so much.
    Sponsor video, mouseover for sound

    Almost all EVs today use conductive charging, but there are lingering concerns. Safety is a potential issue, especially in wet conditions. Home-based 110V or 220V systems take up to 10 hours to fully recharge an EV. Public fast-charging stations have more power available and can charge EVs in much less time, but they take up large amounts of space, and the equipment can be stolen. Also, fast chargers can degrade battery life.

    Wireless charging has been around for years in low-power consumer applications – wireless shavers are widely available, and electric toothbrushes have used it since the early 1990s. Even the medical field is using wireless charging for subcutaneous implants.

    In automotive, wireless charging was a feature of the GM EV1, the first mass-produced EV from a major manufacturer. The EV1, as well as a few hundred first -generation Toyota RAV4 EVs and Chevrolet S10 EVs, charged via induction using a paddle conforming to the J1773 standard.

    There were three charging levels

    Unfortunately for J1773, in 2001 the California Air Resources Board (CARB) decided on J1772, a conductive (wired) charging interface, as the standard for California EVs, causing its demise.

    After that, progress in wireless charging has been glacial, even though electric vehicles have been a part of the mainstream automotive landscape since the introduction of the Toyota Prius in 1997.

    Now, though, the future is looking brighter. In its research report, “Wireless Charging Systems for Electric Vehicles”, Navigant Research forecasts that worldwide sales of wireless EV charging equipment for light-duty vehicles will grow by a compound annual growth rate (CAGR) of 108% from 2013 to 2022, achieving annual sales of slightly less than 302,000 units in 2022.

    Wireless Charging Systems for Electric Vehicles

  34. Tomi Engdahl says:

    Qi Wireless Charging Standard
    - details and specifics about the Qi Wireless Charging Standard developed and promoted by the Wireless Power Consortium..

    Qi, pronounced chee, has become the accepted standard for wireless charging.

    In order to provide interoperability, a key requirement for wireless charging, it was necessary to develop a standard that could be adopted by the major manufacturers. In this way the Qi charging standard enables one charger to be used for devices from many different manufactures and in this way become an accepted approach. If different chargers were required, this would require many different chargers for different devices and lead to confusion in the marketplace.

    Accordingly the Qi wireless charging standard has become the accepted solution.

    The name Qi comes from Asian philosophy where it means “vital energy” which relates to wireless charging which can be seen as an intangible flow of power.

    In order to be able to provide a standard for wireless battery charging technology, an industry group called the Wireless Power Consortium was set up.

    The Wireless Power Consortium held its first meeting in Hong Kong in December 2008. Since its inception its membership has grown from the eight initial companies to over 100.

    In August 2009, the Wireless Power Consortium published the Qi low power specification, and then just a month later the first product was certified.

    The Qi standard has been developed by the Wireless Power Consortium and is applicable for electrical power transfer over distances of up to 40 millimetres (1.6 inches).

    The Qi wireless charging standard uses a power transmission pad that is akin to the charger that would be used in a normal wired system, and a compatible wireless power receiver that is located in the device to be charged. The power transfer then takes place using magnetic induction.

    There are two categories for Qi wireless chargers:

    Low power: The low power category covers chargers that can deliver power in the range 0 – 5 watts. This will cover most of the domestic portable devices like mobile phones, music players, Bluetooth earpieces, etc..
    Medium power: Chargers in the medium power category can deliver power up to 120 watts.

    Within any Qi wireless charging system, there are two main elements:

    Base Stations: The Qi base station is the device that provides inductive power for the wireless transmission. As such it contains a power transmitter of which a major element is the transmitting coil. The overall Qi charger typically has a flat surface. This is normally referred to as the Interface Surface. The mobile device or devices may be placed on top of this surface.
    Mobile Devices: The Qi mobile devices are those which consume the wirelessly transmitted power. This is typically used to charge the battery contained within the mobile device.

    To keep the efficiency as high as possible, it is necessary to ensure that he coupling between the transmit and receive coils is as high as possible.

    The frequency used for Qi chargers is located between about 110 and 205 kHz for the low power Qi chargers up to 5 watts and 80-300 kHz for the medium power Qi chargers.

    Qi data protocol

    The Qi wireless power standard includes the capability for the base station and mobile device using a limited data transmission system. This enables the charge and base station to communicate to provide information about state of charge and the like. In this way, the mobile device can inform the base station when it is charged, etc.. In this way the base station can adapt its output to meet the needs of the mobile device and removing power transmission the mobile device is fully charged.

    In operation, initial detection occurs as a result of the deection of a change in capacitance or resonance of the transmitter coil. Once an object has been detected the base station validates the device placed on it for Qi charging compatibility. The base station sends an 8 bit data string. The receiving mobile device has to respond and provide the signal strength. The base station then sends multiple digital pings to provide information about the optimum positioning of the mobile device. Only when the device has been validated and the information been passed will charging commence. During the Qi charging process, the mobile device sends control data packets to adjust the power level and finally terminate charging.

  35. Tomi Engdahl says:

    A Qi wireless charger: Resonant as well as Inductive

    All Qi receivers (phones, sleeves, backdoors, and charging cards) that have shipped in the last 3 years and continue to ship, can be charged in inductive mode as well as resonant mode. It is the transmitter (wireless charger) that defines the operation mode.

    This video shows a wireless charger that can power all standard Qi phones and tablets at any distance between 0 and 30 mm.

    In the video you see the wireless charger operating in resonant mode as well as in inductive mode.

    Wireless charging in inductive mode

    Most Qi transmitters use tight coupling between coils. In that configuration, the best results are achieved by operating the transmitter at a frequency that is slightly different from the resonant frequency of the Qi receiver. Off-resonant operation gets you the highest amount of power at the best efficiency. This operating mode is called “inductive”.

    The transmit and receive coils are tightly coupled when (a) the coils have the same size, and (b) the distance between the coils is much less than the diameter of the coils.

    Wireless charging in resonant mode

    When the distance between receiver and transmitter increases, the magnetic coupling between the coils decreases. Systems with a low coupling factor have to operate at the resonant frequency of the receiver. This mode is called “resonant”.

    The tradeoff between resonant and inductive mode

    Loosely coupled systems trade-off larger distance at the cost of lower power transfer efficiency and higher electromagnetic emissions.

  36. Tomi Engdahl says:

    Over-The-Air Charging Is The Future
    Proliferation is still 10 years away, DesignCon speaker says

    The future of wireless charging isn’t current coil-based systems, a speaker at Design Con said. Further, standardization won’t drive this kind of wireless charging adoption among consumers.

    Existing wireless charging systems that use magnetic induction or resonant technology typically require plugging a mat in to the wall. Those systems also require users to place their device on a specific spot and have sub-optimal charging efficiency – “It’s not really revolutionary,” said Meng He, Maxim Integrated’s power product executive business manager.

    While the large industry groups such as AirFuel Alliance and the Wireless Power Consortium (WPC) battle for wireless charging dominance in furniture and cars, the answer is in the air. Far field communications – which He defines as beaming focused power to coupled devices at specific locations– will ultimately triumph in the wireless charging race.

    Infrared systems such as Wi-Charge, RF systems including Energous’ WattUp and Cota, and ultrasound from uBeam will ultimately trump wired systems because they allow for freedom of movement and act more like Wi-Fi.

    There are many challenges that must be overcome before any of these systems can proliferate

    none of the following issues can be compromised:

    Mobility: Over-the-air charging systems must be mobile and easily able to follow multiple receivers.

    Safety: Many consumers still need to be convinced that charging over the air is safe.

    System interference: Low level analog and digital signals can be effected by EMI/RFI. Both inductive and resonant coil systems are subject to interference, while only ultrasound and infrared over-the-air systems are interference free.

    Cost: Purchasing a system can be expensive, though He said the iPhone 6 averages 47 cents/year to charge while a home security system costs 6 cents a day.

    Dead battery charge: Near field charging (Qi and AirFuel standards) can revive a dead battery, but far field charging cannot because the receiver must constantly send out a signal to be linked to a power router.

    Despite these engineering challenges, He is hopeful about a wire-free future where the ecosystem coalesces to create a great product that needs adopting.

  37. Tomi Engdahl says:

    Tim Culpan / Bloomberg Business:
    Sources: Apple working on wireless charging tech for iOS devices that works over a distance, may be released as soon as next year

    Apple Said Developing Wireless-Charged Phone for as Soon as 2017

    Apple Inc. is working with partners in the U.S. and Asia to develop new wireless charging technology that could be deployed on its mobile devices as soon as next year, according to people familiar with the plans.

    Apple is exploring cutting-edge technologies that would allow iPhones and iPads to be powered from further away than the charging mats used with current smartphones, the people said, asking not to be identified as the details are private. The iPhone maker is looking to overcome technical barriers including loss of power over distance with a decision on implementing the technology still being assessed

    With iPhones and iPads generating more than three quarters of Apple’s revenue, new technologies can give its devices an edge and help the company sell products at a premium in a slowing market. Samsung Electronics Co., Sony Corp. and Google Inc. are among rivals that have released wirelessly-charged smartphones that still require proximity to a charging plate.

    Efficiency of power transfer decreases as the distance between transmitter and receiver grows, which means batteries take longer to recharge.

    Developing Technology

    In 2010 Apple made a patent application outlining a concept of using an iMac personal computer as a hub for wirelessly recharging at a distance of about 1 meter using a technique called near-field magnetic resonance. Apple currently uses a similar technique, called induction, to charge its Watch within millimeters of the power source.

    Semiconductor makers Broadcom Corp. and Qualcomm Inc. are among those who have developed or are developing technology and standards for wireless charging.

  38. Tomi Engdahl says:

    Wireless charger-receiver fits tiny hearing aids

    Linear Technology’s LTC4123 combines a 30-mW wireless receiver with a constant-current/constant-voltage linear charger for NiMH batteries. The device’s low-profile 2×2×0.75-mm package and low external component count make it well-suited for hearing aids and other low-power portable devices, such as smart cards and fitness devices.

    An external resonant LC tank circuit connected to the LTC4123 enables the IC to receive power wirelessly from an alternating magnetic field generated by a transmit coil.

    LTC4123 – Low Power Wireless Charger for Hearing Aids

    1.5V, 25mA Linear Single-Cell NiMH Charger

    The LTC®4123 is a low power wireless receiver and a constant-current/constant-voltage linear charger for NiMH batteries. An external programming resistor sets the charge current up to 25mA. The temperature compensated charge voltage feature protects the NiMH battery and prevents overcharging.

  39. Tomi Engdahl says:

    iPhone, iPad Wireless Charging May Come By 2017

    The smartphone market is growing more competitive by the day, with consumers demanding the premium materials and features that upper-tier manufacturers like Apple have provided.

    In an effort to stay ahead of its rivals — and in the face of flagging iPhone and iPad sales, Apple is planning to introduce wireless charging on the two devices as early as 2017, according to a Bloomberg report.

    The report, which quotes unnamed sources familiar with the plans, said Apple is working with partners both in the US and Asia to resolve some of the issues inherent in wireless charging technologies.

    Apple Developing Wireless-Charged iPhone for as Soon as 2017

  40. Tomi Engdahl says:

    Wireless charger-receiver fits tiny hearing aids

    Linear Technology’s LTC4123 combines a 30-mW wireless receiver with a constant-current/constant-voltage linear charger for NiMH batteries. The device’s low-profile 2×2×0.75-mm package and low external component count make it well-suited for hearing aids and other low-power portable devices, such as smart cards and fitness devices.

    An external resonant LC tank circuit connected to the LTC4123 enables the IC to receive power wirelessly from an alternating magnetic field generated by a transmit coil.

  41. Tomi Engdahl says:

    IoT devices get wirelessly electricity

    sraeli Wi-carge a commercial mass technology which is able to transfer electric power to nearly ten meters. The technique could be used to charge mobile phones, in addition to a home even if IoT devices.

    The technology is based on IR lasers. In the conventional laser cavity is divided into a transmitter and a receiver of the fixed part of the device to be recharged. between them arises spontaneously resonator, when they have a line of sight to each other.

    The power is transferred between the transmitter and the receiver amplifier of the photocell through the free air link. While the connection is interrupted, the power transmission gain is lost. This is a good safety factor, as normally the transmitter acts as a secure Class 1 IR lasers.

    Source: http://www.uusiteknologia.fi/2016/02/05/iot-laitteille-sahkoa-langattomasti/

    More: http://www.nanobitteja.fi/uutiset.html?39778

  42. Tomi Engdahl says:

    Wireless power transfer based on magnetic quadrupole coupling in dielectric resonators

    We numerically investigate a magnetic resonant wireless power transfer system based on high refractive index  dielectric  resonators. We propose to operate at magnetic quadrupole mode of the resonators to enlarge the efficiency due to minimization of ohmic and radiation losses. Numerical estimation predicts the 80% efficiency of the wireless power transfer (WPT) system operating at quadrupole mode at 300 MHz. Moreover, the system operating at magnetic quadrupole mode is capable of transferring power with 70% efficiency when the receiver rotates 90°. We verify the simulated results by experimental investigation of the WPT system based on microwave   ceramic   resonators (ε = 80 and tanδ = 10−4).

  43. Tomi Engdahl says:

    BU-412: Charging without Wires
    Find out about energy loss and higher temperature when charging on a pad.

    Wireless charging may one day replace plugs and wires similar to how Bluetooth and Wi-Fi have modernized personal communication. The concept rests on inductive coupling using an electromagnetic field that transfers energy from the transmitter to the receiver.

    Wireless transfer of power is not new. In 1831, Michael Faraday discovered induction in sending electromagnetic force through space. In the late 1800s and the early 1900s, Nicola Tesla demonstrated wireless broadcasting and power transmission. The experiments in Colorado Springs in 1899 lead to the Wardenclyffe Tower in New York. Tesla wanted to prove that electrical power could be transmitted without wires, but lack of funding halted the project.

    Wireless charging shares similarities with radio transmission sending signals by electro-magnetic fields. Wireless charging operates in a near field condition in which the primary coil produces a magnetic field that is picked up by the secondary coil in close proximity. The radio transmitter, on the other hand, works on the far field principle by sending waves that travel through space.

    Wireless charging is classified into inductive charging, radio charging and resonance charging. Most of today’s wireless chargers use inductive charging with transmit and receive coils in close proximity. Electric toothbrushes were one of the first consumer goods to adopt this method and mobile phones might become the largest growing sector because of convenience.

    Radio charging serves low-power devices operating within a 10-meter (30 feet) radius from the transmitter to charge batteries in medical implants, hearing aids, watches, entertainment devices and RFID (radio frequency identification) chips. The transmitter sends a low-wattage radio wave and the receiver converts the signal to energy.

    Larger batteries for the electric vehicle and other uses use resonance charging by making a coil “ring.” The oscillating magnetic field works within a one meter (3 feet) radius. To stay in the power field, the distance between transmit and receive coil must be within a quarter wavelength (915Mhz has a wavelength of 0.328 meters or one foot).

    Resonance charging is not limited to high wattage wireless chargers; it is used at all power levels. While a 3kW-system for EV charging achieves a reported efficiency of 93–95 percent with a 20cm (8”) air gap, a 100W system is better than 90 percent efficient; however the low-power 5W systems remains in the 75–80 percent efficiency range. Resonance charging is still in experimental stages with an agreed standard.

    Wireless charging needed a global standard and the WPC (Wireless Power Consortium) accomplished this in 2008 by introducing the Qi norm. This opened the door for device manufacturers to offer chargers for Qi-compatible devices with 5 watts of power; 10W and higher is in preparation.

    Modern wireless charging adheres to a complex handshake to identify the device to be charged. When placing a device onto the charge mat, a change in capacitance or resonance senses its presence. The mat then transmits a burst signal; the qualified device awakens and responds by providing identification and signal strength status. These signals are often used to improve the positioning of the receiver or enhance magnetic coupling between mat and receiver.

    The charge mat only transmits power when a valid object is recognized, which occurs when the receiver fulfills the protocol as defined by one of the interoperability standards. During charging, the receiver sends control error signals to adjust the power level. Upon full charge or when removing the load, the mat switches to standby.

    Transmit and receive coils are shielded to obtain good coupling and to reduce stray radiation. Some charge mats use a free moving transmit coil that seeks the object placed above for best coupling, others systems feature multiple transmit coils and engage only those that are in close proximity with the object.

    WPC was very careful when releasing Qi; the first version had a power limit of 5 watts. A medium-power version of up to 120 watts is in the works but this norm must meet stringent radiation standards before release. Radiation prompts health concerns and these are raised by folks living next to mobile phone towers and Wi-Fi stations. Interoperability and backwards compatibility with 5W systems also play a role.

    Going wireless demands a 25 percent cost premium on the charging station, a burden that also affects the receiver.

  44. Tomi Engdahl says:

    Toshiba Electronics Europe has introduced a new wireless charging transmitter circuit, which supports downloads 15 watts of power.

    TC7718FTG circuit WPC supports the consortium to develop the Qi charging technology version 2.1.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=4029:15-watin-teholla-langattomasti&catid=13&Itemid=101

  45. Tomi Engdahl says:

    Wireless charging circuit for all standards

    Wireless charging one problem has been that has been available in competing mutually incompatible standards. Intergrated Device Technology virtually eliminates the problem with a new IC that support all three mainstream technologies

    The wireless downloading was a long time in practice three competing technology, Qi, A4WP and PMA. Now there are no longer two, when A4WP and PMA have joined together as the new AirFuel Alliance. Qi is in turn driven by the Wireless Power Consortium’s standard for cordless charging.

    IDT’s new transmitter and receiver circuits that support both the Qi- techniques Airfuel 5 and 10 watts of power levels.

    P9724-circuit is 5 watts of power charging, with integrated buck converter circuit. P9762 is, in turn, 10-watt version.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=4039:langaton-latauspiiri-kaikkiin-standardeihin&catid=13&Itemid=101

  46. Tomi Engdahl says:

    ast year was sold for 144 million wireless charging receiver circuit. While the prior art around the hype sometimes smile, it is already a mature technology. This is demonstrated by the fact that technology can be implemented a whole new range of applications. Even wirelessly rechargeable coffee mug.

    Integrated Device Technology and Digi-Key held a design contest, which was applied for the new wireless charging utilizing the devices and applications.

    The theme of the competition was “Power Without boundries” that is, flows without limits

    IHS Research’s figures show that wireless charging is switched to a mature technology, the rising phase. Last year, growth came circuits sale by as much as 160 per cent. IHS predicts that in 2020, sold one billion wireless charging circuit, and in 2025 reached two billion.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=4188:langattomasti-ladattava-kahvimuki&catid=13&Itemid=101

  47. Tomi Engdahl says:

    On the Go Coffee Maker © Apache-2.0

    It is to keep the Coffee warm and also to make the coffee while travelling… It is powered by IDT wireless charger


Leave a Comment

Your email address will not be published. Required fields are marked *