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.

Qi
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.

WiPower
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.

A4WP
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.

199 Comments

  1. Tomi Engdahl says:

    Gov’t Researchers Develop Wireless Car Chargers That Are Faster Than Plug-ins
    https://hardware.slashdot.org/story/16/04/06/0043255/govt-researchers-develop-wireless-car-chargers-that-are-faster-than-plug-ins

    The U.S. Department of Energy has demonstrated a 20,000 watt (20KW) wireless car-charging system that offers three times the efficiency of today’s plug-in systems for electric vehicles (EVs). The research is the first step in creating a 50KW wireless charging system that may someday allow roadways to charge vehicles while they are being driven.

    ORNL surges forward with 20-kilowatt wireless charging for vehicles
    https://www.ornl.gov/news/ornl-surges-forward-20-kilowatt-wireless-charging-vehicles

    Reply
  2. Tomi Engdahl says:

    Wi GaN
    https://issuu.com/eeweb/docs/04-2016_wi_1.pages/18?e=7607911/34856091

    class E amplifier for 6.38 MHz loosely coupled resonant wireless power applications

    This amplifier is AirFuel compatible, and capable of delivering 6.5W load power

    Reply
  3. Tomi Engdahl says:

    Josh Constine / TechCrunch:
    uBeam’s former VP of engineering argues in 20 blogs posts that the company’s technology won’t work, says original CTO and new CFO have left

    Wireless charging startup uBeam accused of being the next Theranos
    http://techcrunch.com/2016/05/11/charged/

    uBeam could be vaporware, according to a blogger claiming to be uBeam’s former VP of engineering. They accuse the startup of being unable to fulfill promises made about its technology.

    uBeam says it’s building a device that could wirelessly charge your phone or other electronics from several meters away. But in a series of blog posts about the startup, the author asserts that the product is a sham. The criticism will increase the pressure on uBeam to reveal a working prototype.

    We contacted uBeam; it did not provide comment. uBeam has repeatedly defended itself against past claims that its technology is impossible, saying it has made scientific breakthroughs, and citing high-profile additions of ultrasound experts to its team, advisors and investors as proof that it has potential.

    TechCrunch has closely covered uBeam because of the potential market size for its technology and the funding it’s received. However, we’ve reiterated our skepticism about the product until we see a live, production-ready demo of cell phone charging at a distance.

    The new claims dispersed across 20 blog posts on “Lies, Damn Lies, and Startup PR” add fuel to this skepticism.

    Energous, a competitor in the wireless space, is accused of also never releasing a working product despite going public and currently having a market cap of $174 million. The author claims Energous is purely designed to financially benefit the founders.

    Venture capitalists in some sectors are increasingly eager to fund serious scientific innovations, although they can be much tougher to do due diligence on than simple software that can be assessed based on immediate market traction. The economics of startups are such that VCs seek risky bets that could provide huge returns, even if it means a high percentage of their investments fail.

    https://www.crunchbase.com/organization/ubeam#/entity

    Reply
  4. Tomi Engdahl says:

    What Adam Grant Got Wrong About Meredith Perry and uBeam
    https://www.linkedin.com/pulse/what-adam-grant-got-wrong-meredith-perry-ubeam-paul-reynolds

    Time to take a look at one of the other components of the whole VC/startup/ biztech world — the Entrepreneurial Book. These are the books you see in the airport promising to teach you how to be a better leader, manager, inventor, or whatever you believe you are in 10 easy to digest feel good chapters. I’ve read a few myself and usually they’re like a sugary treat — makes you feel good when you read it, but no long lasting benefit, and might actually rot your teeth a little.

    Let’s start with the biggie.

    She (Perry) did something that flew in the face of every piece of wisdom she had heard about influence. She simply stopped telling experts what it was she was trying to create. Instead of explaining her plan to generate wireless power, she merely provided the specifications of the technology she wanted. Her old message had been: “I’m trying to build a transducer to send power over the air.” Her new pitch disguised the purpose: “I’m looking for someone to design a transducer with these parameters. Can you make this part?”

    In case you hadn’t noticed, Meredith Perry gets plenty of publicity for uBeam, and the press coverage made it very, very clear what she was trying to do. So apparently us engineers are super tech savvy but can’t Google some articles? No — before I’d even replied to the first contact, I knew exactly what they were doing.

    Once I get the general idea of what you’re trying to do, I already know the rough specs of what you are looking for. If you give me specs that are different, I’ll try to find out why, whether it’s that I’m not understanding your requirements, or you’re not understanding the issues. The converse is this — if you give me specs, I have a pretty good idea of what you’re trying to do. I’ve shocked plenty of cold callers when I’ve worked out what their “super secret” project is from just a couple of questions.

    Then there’s the engineering side of things. If you give me a spec for something way, way different (let’s say less difficult) than what you actually need, I’m going to make choices and compromises in the design to hit that spec, and not the 10x you really want. Like most engineers I pride myself on delivering a good product that meets (and maybe slightly exceeds) your needs in an economical manner —if I overbuild like that, you as a customer will likely be unhappy with the invoice, and reasonably so.

    Then there’s this:

    It was enough to attract a first round of funding and a talented chief technology officer who had initially been highly skeptical. “Once I showed him all the patents, he said, ‘Oh sh*t, this actually can work.’ ”

    I have to wonder, did the author confirm this statement with the CTO? Which of the engineers that work(ed) for uBeam did the author interview to confirm their initial skepticism, or that the pitch to them was anything other than what we all see in the press? Not me.

    Adam Grant might want uBeam to be the story that’s another proof point for his thesis, but in my opinion it doesn’t hold water.

    Reply
  5. Tomi Engdahl says:

    Is uBeam the new Theranos?
    Former engineer claims ultrasound charging tech doesn’t work
    http://www.theregister.co.uk/2016/05/13/is_ubeam_the_new_theranos/

    A former VP of engineering at a startup that promises fast, wireless charging of electronic devices has claimed that the technology doesn’t work and its CEO is misleading people.

    The engineer in question, Paul Reynolds, posted his claims – as well as a number of other critical pieces on uBeam’s CEO Meredith Perry – on a personal blog called Lies, Damn Lies and Startup PR.

    The blog was recently noticed and has become the talk of Silicon Valley, in part because of the company’s backing from a number of VC heavyweights.

    http://liesandstartuppr.blogspot.fi/

    So to confirm, I am Paul Reynolds, former VP of Engineering at uBeam, responsible for transducers and acoustics. I was hired on as a consultant in the summer of 2013, was offered the VP position soon after, and like everyone else remained a consultant until our funding round in Sept 2014 when we all converted to actual employees. As part of the team that pitched the Series A round, I saw the company grow from literally working in a garage on a shoestring budget, to a total of around $23 million raised, until my departure in October 2015.

    Reply
  6. Tomi Engdahl says:

    Improving Wireless Power Transmission Capabilities
    https://www.eeweb.com/blog/eeweb/improving-wireless-power-transmission-capabilities

    As devices become increasingly sophisticated, the means by which they’re powered must be improved upon too.

    Wireless power transfer (WPT), or wireless energy transmission, is the transmission of electrical power from a power source to a consuming device without using discrete man-made conductors. By eliminating the use of physical cables, connectors, and electrical plugs, wireless charging provides a number of advantages including simplicity and safety. From smartphones and small electronic devices to industrial equipment, wireless power maintains a reliable transfer of power so that all forms of the device and equipment are charged and ready for use.

    Reply
  7. Tomi Engdahl says:

    Metamaterials Boost the Distance for Wireless Charging
    http://www.eetimes.com/document.asp?doc_id=1329721&

    Researchers at the University of Barcelona in Spain have used metamaterials to improve the performance of wireless charging systems.

    Current wireless charging uses induction to charge through a special case adapted to the device and a charging base connected to an electrical socket. When the device is placed on top of the base, this generates a magnetic field which induces an electric current inside the case and, without the need of using any cables, the device is charged. If the device is separated from the base, the energy is not transferred efficiently enough and the battery cannot be charged.

    The system created by the researchers overcomes these limitations. It is made up of metamaterials which combine layers of ferromagnetic materials, such as iron compounds, and conductor materials such as copper. The metamaterials cover the emitter and receiver and enable transferring energy between the two, allowing a tradeoff of higher efficiency for a longer distance. With the use of metamaterial crowns researchers were able in the lab to increase the transmission efficiency 35-fold.

    “Enveloping the two circuits with metamaterial shells has the same effect as bringing them close together; it’s as if the space between them literally disappears,”

    The device has been patented by the University and the researchers say companies from several different countries have already shown interest in applying the technology.

    Reply
  8. Tomi Engdahl says:

    Kit enables sub-3W wireless charging
    http://www.edn.com/design/design-tools/development-kits/4442065/Kit-enables-sub-3W-wireless-charging?_mc=NL_EDN_EDT_EDN_consumerelectronics_20160525&cid=NL_EDN_EDT_EDN_consumerelectronics_20160525&elqTrackId=15d69911a4b84509a60540616f6e2daf&elq=c2de9d89092b49d1a9cf1168b1a43a6c&elqaid=32376&elqat=1&elqCampaignId=28289

    This reference kit aims at designing wireless charging into smartwatches, fitness monitors, and other wearables. IDT’s wireless power reference kit comprises a Qi-based transmitter and receiver for designs requiring 3W or less.

    Suited for applications ranging from 0.5-3W, the transmitter (P9235A-R) and receiver (P9027LP-R), support three different coil size options for various applications, form factors, and power levels. IDT already has a similar kit at the 5W power level.

    The wireless power kit containing the transmitter, receiver, and additional coils is available now for $70.

    Reply
  9. Tomi Engdahl says:

    Mouser says it took to sell NXP’s new single-chip wireless Qi charging circuit. NXQ1TXH5-circuit can be implemented in supporting the Wireless Power Consortium’s standard 1.2-charging, which transfers 8 watts of continuous power.

    The solution requiring minimal external components, chassis, Qi-compatible coil must be the type of A5, A11, A12, and A16.

    The transmitter circuit power consumption is only 10 milliwatts. Power transfer is controlled by two channels ASK connection.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=4608:langattomien-latauspiirien-valikoima-laajenee&catid=13&Itemid=101

    Reply
  10. Tomi Engdahl says:

    Home> Tools & Learning> Products> Product Brief
    Kit demos multimode wireless charger
    http://www.edn.com/electronics-products/other/4442385/Kit-demos-multimode-wireless-charger?_mc=NL_EDN_EDT_EDN_productsandtools_20160725&cid=NL_EDN_EDT_EDN_productsandtools_20160725&elqTrackId=18cf1b9bbc3b42c28abb2ea3b35394d2&elq=56f2aa29c3fc4e7fbb7d17f775b6d7cb&elqaid=33172&elqat=1&elqCampaignId=29003

    EPC’s 9121 wireless power-charging demonstration system simplifies the evaluation process of using eGaN FETs and ICs for wireless charging regardless of the standard used in the receiving device. The EPC9121 is compatible with both of the current industry standards for wireless power charging: the Wireless Power Consortium Qi standard and the AirFuel Alliance standard.

    Based on inductive coupling, the Qi standard uses a low-frequency (<300 kHz) approach. AirFuel employs a magnetic resonant technology that has both low-frequency (100 kHz to 315 kHz) and high-frequency (6.78 MHz) requirements.

    The EPC9121 wireless power-charging demonstration system costs $907.20 and is available from Digi-Key.

    EPC9121 – 10 W Multi-Mode Wireless Power Kit
    http://epc-co.com/epc/Products/DemoBoards/EPC9121.aspx

    Reply
  11. Tomi Engdahl says:

    Wireless transmitter is QI-certified
    http://www.edn.com/electronics-products/other/4442486/Wireless-transmitter-is-QI-certified?_mc=NL_EDN_EDT_EDN_productsandtools_20160808&cid=NL_EDN_EDT_EDN_productsandtools_20160808&elqTrackId=113db9b120154645a48a7abe22f1922c&elq=8c3881627b83440eaffdce5d3734fafc&elqaid=33366&elqat=1&elqCampaignId=29167

    The bq501210 is a Qi-certified WPC V1.2-compliant wireless power transmitter from Texas Instruments that delivers up to 15 W, while enabling 84% system efficiency with less thermal dissipation. It supports multiple fast-charging protocols and is backward-compatible with existing 5-W WPC receivers.

    With integrated logic functions, this digital controller periodically pings the surrounding environment for available devices to be powered, detects if a foreign metal object is present on the charging pad, monitors all communication from the device being wirelessly powered, and adjusts power applied to the transmitter coil per feedback received from the power device. The bq501210 also manages fault conditions associated with the power transfer.

    The bq501210’s HVDCP (High-Voltage Dedicated Charging Port) protocol negotiates with AC/DC wall adapters to adjust the input voltage. The rail control output provides power to deliver a full 15 W with inputs between 15 V and 19 V.

    http://www.ti.com/product/bq501210?HQS=pwr-bms-emt-bq501210-pr-pf-bq501210-wwe

    Reply
  12. Tomi Engdahl says:

    Rectenna Serves 2.45-GHz Wireless Power Transmission
    http://mwrf.com/systems/rectenna-serves-245-ghz-wireless-power-transmission?code=UM_Classics072a&utm_rid=CPG05000002750211&utm_campaign=7142&utm_medium=email&elq2=ac0be696e28240d0ac4b282d07ef35cc

    This fairly simple and straightforward rectenna design can be applied for conversion of energy at RF/microwave frequencies to usable DC power.

    Reply
  13. Tomi Engdahl says:

    HF-Powered Drone Antenna
    http://hackaday.com/2016/08/24/hf-powered-drone-antenna/

    Amateur radio has a couple of sweet allocations in the VHF bands, but because the signals don’t reflect off the ionosphere like shortwave signals, the use is limited basically to line-of-sight. One workaround is to use a repeater with a tall antenna, but that requires a lot of infrastructure or a mountainside lair.

    What if you could just fly your antenna up in a drone?

    This is where our story gets strange. [Glenn, n6gn] has built a rig that transmits significant power over distance using a very thin wire. The trick is to send the power at high-frequency down the wire, at which point it becomes more like a transmission line than a conductor.

    [Glenn] isn’t quite there yet, but he’s been able to send almost 200 watts down 0.32 mm wire and he’s proven the basic principles of operation using balloons for lift.

    SWTL Powered Drone/Antenna
    http://www.sonic.net/~n6gn/SWTL_Powered_Drone_Antennas.html

    In addition to providing a very wide bandwidth information transmission system using existing power lines, SWTLs are interesting as a means of transmitting significant power for supporting high altitude antennas. A Video demonstrating ~40dB improvement to channel capacity through the use of a helium balloon aerostat, supporting a light weight wide-band antenna, fed with SWTL has already been shown.

    However, the same SWTL that is used to provide connection from ground-mounted communications equipment to the elevated antenna can simultaneously support quite high power transmission for flight power for the aircraft. If, on a wavelength/frequency separate from the communications channels, a high power transmitter transmits RF energy up the SWTL to the aircraft, that power can then be rectified back to DC and used to operate the drone’s motors. A ground-powered system like this has several “power supplies”.

    1. Power Supply to convert AC Mains power to DC
    2. Power Amplifier to convert DC power to RF power
    3. Rectifier to convert RF power back to DC power
    4. Power Supply to Convert DC power from rectifier to proper voltage and current to power motors.

    Supplies (1) and (2) are ground-mounted and separated from airborne supplies (3) and (4) by the SWTL/tether.

    Common drone sizes are from 350mm to 650mm. Craft of this size might require between 150W and 500W of power to maintain a hover in the absence of wind. Thus, a flight system using a ground transmitter, SWTL, Rectifier and DC power converter might need to be able to provide a significant fraction of one horsepower in order to operate continuously.

    Reply
  14. Tomi Engdahl says:

    Drone Flys 12 cm on Wireless Power
    http://hackaday.com/2016/09/17/drone-flys-12-cm-on-wireless-power/

    [Sam M] wrote in with a quick proof-of-concept demo that blows our socks off: transferring enough power wirelessly to make a small quadcopter take flight. Wireless power transfer over any real distance still seems like magic to us. Check out the videos embedded below and you’ll see what we mean.

    What’s noteworthy about this demo is that neither the transmitter nor the receiver are particularly difficult to make. The transmitting loop is etched into a PCB, and the receiver is made of copper foil tape. Going to a higher frequency facilitates this; [Sam M] is using 13.56 MHz

    High-frequency power switching puts real demands on the transistors, though, and the one [Sam M] is using is cutting-edge and specifically designed for this application.

    Topic: MHz power electronics and their application to wireless power for drones
    http://www.eevblog.com/forum/projects/mhz-power-electronics-and-its-application-to-wireless-power-for-drones/msg1027532/#msg1027532

    Reply
  15. Tomi Engdahl says:

    Wireless charger fits sealed wearables
    http://www.edn.com/electronics-products/other/4442791/Wireless-charger-fits-sealed-wearables?_mc=NL_EDN_EDT_EDN_today_20161006&cid=NL_EDN_EDT_EDN_today_20161006&elqTrackId=87c82a03a73a46bc88b93151d7f7a632&elq=940ea477aa64463d9a9d75d00ac8fe3e&elqaid=34232&elqat=1&elqCampaignId=29884

    STMicroelectronics’ STWBC-WA/STWLC04 miniature chipset for wireless battery charging allows smaller, simpler, and sealed sports wearables, as well as medical sensors and remote controllers.
    Comprising the STWBC-WA charging-transmitter controller and STWLC04 wireless battery-charger receiver, the chipset enables power transfer up to 1 W using very small coils: just an 11-mm diameter coil on the receive side and a 20-mm coil for the transmitter.

    Power-transfer capability can be increased to 3 W by using larger coils and a full-bridge circuit on the transmitter side. Further, the elimination of a conventional charging connector simplifies enclosure design and eases sealing to prevent contamination by dirt or moisture.

    Reply
  16. Tomi Engdahl says:

    Daimler: First to Go Wireless Charging
    http://www.eetimes.com/document.asp?doc_id=1330617&amp;

    PARIS — It’s official. The upcoming 2017 Mercedes-Benz S550e will become the first commercially available plug-in hybrid featuring Qualcomm’ wireless electric vehicle charging (WEVC) technology.

    Drivers of the new car equipped with the wireless charging option “will simply park atop a special ‘hot spot’ pad and charging will begin — no cables to manage or untangle, just ‘park it and charge it,’” Qualcomm claimed.

    Qualcomm has been engaged in a number of WEVC license agreements with Tier Ones

    Qualcomm also cut a similar deal with Brusa Elektronik (Sennwald, Switzerland) a year ago.

    Thomson said that Qualcomm’s wireless charging technology has been “successfully integrated and tested” on a number of different vehicle platforms. They include: Renault Fluence, Renault Zoe, Nissan Leaf, BMWi3, BMWi8, Mitsubishi Imiev, Honda Accord and even the Rolls Royce 102 ex experimental electric vehicle.

    So, how big a deal is the 2017 Mercedes-Benz S5520e with wireless charging capabilities?

    Kevin Mak, senior analyst, Automotive Practice at Strategy Analytic, told us, “We suspect it will be small, given that it is a cost option in the $1,000-2,000 range (in addition to the standard conductive charging system) and is only available on the most expensive model from a luxury auto brand.”

    But it is certainly symbolic, because Strategy Analytics believes that the Mercedes-Benz S550e is the first series production plug-in model to feature wireless charging.

    Competing technologies
    Notably, Qualcomm’s WEVC isn’t the only available wireless charging technology.

    Competing technologies include those developed by WiTricity, KAIST, Momentum Dynamics and Evatran. Most companies have their own IP for wireless electric vehicle charging technology. Among them, Qualcomm and Witricity have been reportedly making headway in licensing their technology to hardware providers.

    Technologies aside, the real force attracting automakers to wireless power is the emergence of SAE J2954.

    Some players are targeting high power rates because long charging times are a major EV drawback, according to the Strategy Analytics’ analyst. Meanwhile, rival conductive charging systems are now moving up the power ratings. CCS (Combined Charging System) is now charging at 150 kW. Its next goal is 350 kW, albeit with heavy cabling and active cooling, to enable a 5 minute fast-charge for 100 km/62 miles range, he noted.

    Qualcomm remains optimistic about differences among wireless electric vehicle charging technologies, largely because of the SAE International’s emerging automotive standards. Qualcomm said in a statement that the companies, along with other OEMs, are “working together to ensure that WEVC technology is included in SAE International’s standards, for short- and long-term benefits.”

    “While the 3.6 kW WEVC system is perfectly adequate to charge a plug-in-hybrid battery, a pure EV with a 30-40 kWh battery needs double or even triple the charging power to fill up in a reasonable amount of time.”

    For the long term, Qualcomm is pushing for wireless charging in the context of autonomous cars: “You cannot call a self-driving car ‘autonomous’ if it cannot fuel/recharge itself.”

    Qualcomm takes a pride that its WEVC technology has been rigorously tested and refined in the Formula E racing series.

    Reply
  17. Tomi Engdahl says:

    Wireless Charging Wades into the Industrial Environment
    http://electronicdesign.com/power/wireless-charging-wades-industrial-environment?code=UM_NN6TI42&utm_rid=CPG05000002750211&utm_campaign=8156&utm_medium=email&elq2=dd4d3b58f0fd412981e29cf0545cb8a8

    Wireless charging, also called wireless power transfer (WPT), is widely used in portable and wearable consumer devices such as smartphones, fitness bands, shavers, and electric toothbrushes. However, it has advantages for industrial applications, too. Industrial applications include electric vehicles, drones, factory automation, handheld terminals, contactless charging of subsea vehicles, and much more.

    Why wireless? Portable equipment in an industrial setting often must operate in a harsh environment, where exposure to moisture, dust, dirt, oil, and other contaminants is an everyday occurrence. With no power connectors to worry about, a wireless-charging system can be made impervious to stray liquids, dust, or gases.

    Another advantage: There’s no danger of an explosion caused by a stray spark when connecting or disconnecting a current-carrying power cable.

    The most popular wireless-charging technology uses near-field charging (NFC), in which a transmitting coil produces a magnetic field that transfers inductive energy to a nearby receiving coil. A

    There are two competing NFC standards. The Wireless Power Consortium (WPC) controls the Qi (“Chee”) standard which has an operating frequency of 100 to 200 kHz; the AirFuel Alliance, formerly known as the Power Matters Alliance (PMA), supports AirFuel Inductive, operating at 100 to 350 kHz. Both systems achieve an overall efficiency of >70%

    Many manufacturers support both standards. Samsung, for example, includes both Qi and AirFuel charging in its Galaxy S6 and S7 smartphones

    Wireless charging is a fast-moving field, For example, Qi has gone through several revisions

    WPC v1.2, introduced in 2015, can deliver up to 15 W. This is defined as “medium power” by WPC, in contrast to the “low-power” 5 W of earlier revisions.

    Why pick a standards-compliant design? Compliance guarantees that transmitters and receivers with different power levels, or devices from different manufacturers, will seamlessly operate together. This convenience isn’t free, though: The OEM must spend the money to join the consortium, then test and certify its components.

    The WPC standard requires the designer to choose a transmitter coil that meets precise specifications for the desired input voltage: 5 V, 12 V, or 19 V. The A5 coil, for example, is a 5-V, 6.3-µH coil with 10 turns of wire, a circular cross-section, and a magnet in the center

    Newer designs are moving to the A11 coil, a very similar design without the magnet.

    A multi-coil solution such as the A6 increases the available charging area

    For maximum coupling, the receiver and transmitter coils should be similar in size. The receiver coil tends to be more complex—it must be very thin, yet withstand vibration, shock, and all of the other indignities suffered by a portable or wearable device.

    WPT Communication

    The receiver (secondary) side controls the amount of power transferred by the transmitter (primary) drive. The secondary communicates with the primary by changing the load seen by the primary.

    Two options are available. A resistive load change changes the amplitude of the transmitter voltage; a capacitive load change gives a time displacement

    The communication scheme is digital, with packets being transferred from the secondary to the primary. The Qi standard specifies a data rate of 2 kb/s with biphase bit encoding.

    Foreign Object Detection (FOD)

    Any metal object, such as a key or a coin, that comes between the primary and secondary coils can absorb a portion of the electromagnetic field. This reduces the efficiency of the power transfer; the object can also heat up and pose a safety hazard.

    An inductive WPC system detects a foreign object by comparing the power received at the receiver with the power sent from the transmitter and looking for power loss. If the power loss exceeds a preset threshold, the transmitter reduces power or shuts down completely and sets an error flag.

    FOD is required by WPC specification v1.1 and later.

    Conclusion: WPT and Industry 4.0

    Industrial users already employ wireless charging in their tablets, point-of-sale terminals, inventory control scanners, etc., but Industry 4.0 represents another huge opportunity.

    Many industrial applications will demand a higher-power solution than the 15-W designs discussed in this article. Whether the solution will be provided by a version of the Qi or AirFuel standards, a proprietary approach, or a combination of all three, remains to be seen.

    Reply
  18. Tomi Engdahl says:

    The fallacy of wireless power
    http://www.infoworld.com/article/2616229/consumer-electronics/the-fallacy-of-wireless-power.html

    Induction chargers promise convenience but use more power and take more space — and they’re not wireless

    Is the convenience enough to matter?
    What these devices promise is convenience: Each time you charge a smartphone or tablet, you save a few seconds by not having to link the MicroUSB, Dock, or Lightning connector to your phone or tablet or to place it precisely in its dock. Instead, you just place the device front side up on a mat. As long as the two inductive surfaces touch, the charging commences.

    “The convenience may look trivial, but if you start using it, you find it isn’t,”

    Convenience is a powerful motivator, and as additional manufacturers build wireless charging into their devices’ skins, more and more users could take advantage of that expedience.

    Reply
  19. Tomi Engdahl says:

    Make your own smart home charging table

    Semtech has introduced a complete wireless charging system that can be installed even under the table top. Choose their own living room table may be downloaded on the platform.

    The solution is called LinkCharge. It supports Sela WPC (Wireless Power Consortium) that AirFuel Alliance charging techniques, that is, practically all commercially available wireless rechargeable smart phones.

    LinkCharge system devices to download a 15-watt maximum power

    Source: http://etn.fi/index.php?option=com_content&view=article&id=5310&via=n&datum=2016-10-28_14:53:48&mottagare=30929

    Video:
    LinkCharge™ CT Installation Overview
    https://www.youtube.com/watch?v=ki2k1TBcg6k

    Reply
  20. Tomi Engdahl says:

    Wireless Charging Market Still Seeks Use Cases
    http://www.eetimes.com/author.asp?section_id=36&doc_id=1330882&amp;

    Outside of cell phone users, the user base for wireless charging has not grown. Is this a lost opportunity?

    Plenty of cell phone users are expressing support for wireless charging, as the recent Wireless Power Summit 2016 in Seattle, Washington demonstrated. But, outside of handsets (which multiplied 40% in the past three years), the user base for wireless charging has not grown. Some are beginning to wonder if this is lost opportunity.

    Identifying wireless charging use is a bit like defining an LED infrastructure: One day analysts predict a flood; the next day nothing happens; then suddenly we’re swimming in it. Some of us predicted the wireless charging market would not take off without a definitive standards agreement among smartphone suppliers. But with loose support for Qi and PMA, wireless cellphone chargers are proliferating along with infrastructure.

    As many as 200 million handsets are now using wireless charging — and most reported their experience to be good, said David Green, an IHS Markit power analyst (in an interview with Smithers Apex). This could multiply to 2 billion charging units by 2026, he said.

    Reply
  21. Tomi Engdahl says:

    20 watts wirelessly

    Wireless charging is increasing rapidly, but still a large part of the available solutions will reach only 5 and, at best, 15-watt output power.

    Semtechin a new solution to download 20 watts of power, so it is already suitable for charging a wide range of larger equipment.

    It is the company’s LinkCharge technology, which uses its own protocol to connect transmitter and receiver. Electrical power is transferred using induction, so there is nothing extraordinary.

    According to Semtech the charging base and receiver link efficiency is 85 percent.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=5582:20-wattia-langattomasti&catid=13&Itemid=101

    Reply
  22. Tomi Engdahl says:

    Adding an IKEA Wireless Charger to a Project
    http://hackaday.com/2017/01/01/adding-an-ikea-wireless-charger-to-a-project/

    IKEA sometimes seems like a DIY store disguised as a furniture store. We may go there looking for a new sofa or kitchen table, but, to the DIY enthusiast, it’s a shop full of possibilities. While wandering through the local IKEA, [Erich Styger] noticed they had some Qi wireless chargers and receivers for a very reasonable price, so he bought a few and added wireless charging to his Mikroelektronika Hexiwear.

    DIY IKEA Wireless Qi Charging for the Hexiwear
    https://mcuoneclipse.com/2016/12/28/diy-ikea-wireless-qi-charging-for-the-hexiwear/

    Reply
  23. Tomi Engdahl says:

    Forget the charging platform – a new technology for recharging meters away

    Energous was founded in 2013 to an American company, which went public in 2014 and the following year introduced the world’s first RF-charging power receiving circuit. It is developed by charging technique is called WattUp and the past couple of years it has been one of the Las Vegas CES fair hot topics.

    WattUp works so that the device comes within the scope of the charging range, it will discuss with WattUp charging transmitter bluetoohin through. If the battery is low, charging starts WattUp.

    In practice, WattUp device – which can be integrated into, say, furniture based on the magnetic charger to charge the usual platforms – to send the RF signal 5.850 – 5,875G frequency receiver that converts RF energy to DC power and charge the battery of the device.

    DA4100-circuit is the ARM Cortex-M0 + -based chip with the same 7×7-mm housings have integrated power management, DC-DC conversion and software required WattUp-sending.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=5757&via=n&datum=2017-01-31_16:09:57&mottagare=30929

    Reply
  24. Tomi Engdahl says:

    Radio Transmitter Chip Beams Power to Smartphones and Hearing Aids
    http://mwrf.com/mixed-signal-semiconductors/radio-transmitter-chip-beams-power-smartphones-and-hearing-aids?NL=MWRF-001&Issue=MWRF-001_20170202_MWRF-001_435&sfvc4enews=42&cl=article_1_b&utm_rid=CPG05000002750211&utm_campaign=9523&utm_medium=email&elq2=9ec644585ae447e39fc2e96f347fac50

    Energous wants to transmit power to everything from smartphones to hearing aids just like signals are sent over Wi-Fi. And on Monday, it released a piece of that puzzle, a radio transmitter chip that works with its wireless battery charging technology.

    The underlying technology is called WattUp and it uses the 5.8 GHz spectrum reserved for for industrial, scientific, and medical applications. An antenna array steers the radio waves into an invisible cloud of RF energy, inside of which devices can charge up. The system can deliver wireless power from up to 15 feet away, the company says.

    That contrasts with most recent wireless battery charging technology, which only spans a few inches and requires devices to be placed directly on a charging pad.

    Founded in 2012, Energous designs the chips required for wireless power transmission, but actual products using its technology have been slow to market.

    “This new IC will be the backbone of our transmitter technology moving forward and our efforts to miniaturize and reduce costs for our customers will allow WattUp transmitters to be included in-the-box with many consumer devices,”

    The new transmitter chip measures 7 millimeters square, compared to the 3 millimeters square of the company’s receiver chips. It integrates an ARM Cortex processor and DC-DC converter on the same chip. Energous says that sample evaluation kits are now available.

    The chip was developed with Dialog Semiconductor, which invested $10 million last November to become the exclusive supplier of WattUp chips and jump start the technology’s adoption

    At the Consumer Electronics Show last month, Energous showed several devices ranging from power dongles and hearing aids that could be charged with WattUp technology. The catch was that they could only be charged on a short-range charging pad, not from 15 feet away.

    Reply
  25. Tomi Engdahl says:

    http://interestingengineering.com/disney-room-wirelessly-charge-all-devices/

    The Disney Research group managed to create a full-coverage wireless power system for all devices in a room. A recently published paper in PLoS One details how the team provided 1900 watts with between 40 to 95 percent efficiency

    The prototype living room manages to power 10 objects, including a smartphone, lamp, an RC car and more.

    The only downside is that the whole room had to be crafted to accommodate the wireless system.

    The prototype living room manages to power 10 objects, including a smartphone, lamp, an RC car and more.

    The only downside is that the whole room had to be crafted to accommodate the wireless system.

    Reply
  26. Tomi Engdahl says:

    Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer
    https://www.disneyresearch.com/publication/quasistatic-cavity-resonance-for-ubiquitous-wireless-power-transfer/

    Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR), which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within. A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power.

    Reply
  27. Tomi Engdahl says:

    Wireless Power Prepares to Hit the Mainstream
    http://electronicdesign.com/wireless/wireless-power-prepares-hit-mainstream?NL=ED-003&Issue=ED-003_20170227_ED-003_620&sfvc4enews=42&cl=article_1_b&utm_rid=CPG05000002750211&utm_campaign=9862&utm_medium=email&elq2=4e4869f9f9ce45dab5f4b3ab8acfcef0

    Fueled by strong opinions from consumers about how devices should charge, wireless-power companies are looking to make wireless charging more accessible while providing “must-have” features.

    The growth in awareness and adoption of wireless-charging technologies is quickly climbing. To keep moving forward, suppliers must understand the needs of the consumers in order to develop and launch better products. A survey on wireless power commissioned by the AirFuel Alliance and several of its members (e.g., WiTricity and Energous) looked into consumer perspectives on wireless-charging technology. Among the highlights:

    71% want wireless charging in their next device, and they are willing to pay for it in public spaces.
    72% say wireless-charging capabilities are important to them, and 62% of those individuals say speed of charge is also critical.
    49% don’t even want to think about plugging in their smartphone or putting devices in a precise position to charge; they just want it to happen.
    93% think wireless charging will become the new norm over the next three years.

    After looking at the survey’s results, it is clear that customers want wireless charging throughout their connected lives—at home, at work, and even when traveling. Ideally, they’d like to get rid of all cords and the different charging ports needed for every device they own.

    The issue of longer battery life is related to battery anxiety, which is rather common. According to the survey, 45% of consumers report that they worry about losing the battery’s charge a few times a day. And almost all users of portable-power devices are concerned about their battery dying. This anxiety might be eliminated by making wireless fast-charging solutions easy to access in public spaces—especially since people are willing to pay for this capability.

    “Just think—everything has become wireless except for the power cord itself,” continues Gupta. “Even autonomous devices, like drones, robots, or AGVs, are not truly autonomous until the cord is gone and humans are not required to charge them up. We are bringing our vision of a future where zero devices need to be tethered to a wall to a reality. Charging cords and power bricks will go the way of the rotary phone.”

    At the moment, the more common wireless-charging technologies are:

    Resonance technology
    Inductive technology
    Radio-frequency-charging technology

    Standard Needed

    Even though wireless-power technology is gaining traction, the lack of standards interoperability is hampering its growth. Meanwhile, IC vendors and ecosystem providers are increasingly offering multi-mode options to support standards like AirFuel and WPC, with transmitters oscillating at different frequencies (e.g., 100-200 kHz, 5.8 GHz, and 6.8 MHz).

    “As consumer awareness of wireless charging continues to increase, they are demanding an experience where they can power up their devices no matter where they are, without precise alignment on a charging pad or giving charging any thought,” says Gupta. “In order for that experience to exist, a universal standard must emerge so that all wireless-charging infrastructure (the devices, charging surfaces, value-added services, and their management) are interoperable.

    Reply
  28. Tomi Engdahl says:

    Suddenly, Wireless Power Transmission Is Everywhere
    http://hackaday.com/2017/02/23/suddenly-wireless-power-transmission-is-everywhere/

    Wireless power transfer exists right now, but it’s not as cool as Tesla’s Wardenclyffe tower and it’s not as stupid as an OSHA-unapproved ultrasonic power transfer system. Wireless power transfer today is a Qi charger for your phone. It’s low power – just a few amps — and very short range. This makes sense; after all, we’re dealing with the inverse square law here, and wireless power transfer isn’t very efficient.

    Now, suddenly, we can transfer nearly two kilowatts wirelessly to electronic baubles scattered all over a room. It’s a project from Disney Research, it’s coming out of Columbia University, it’s just been published in PLOS one, and inexplicably it’s also an Indiegogo campaign. Somehow or another, the stars have aligned and 2017 is the year of wirelessly powering your laptop.

    In practice, the QSCR from Disney Research takes the form of a copper pole situated in the center of a room with the walls, ceiling, and floor clad in aluminum. This copper pole isn’t continuous from floor to ceiling – it’s made of two segments, connected by capacitors. When enough RF energy is dumped into this pole, power can be extracted from a coil of wire.

    As with all wireless power transmission schemes, there is the question of safety. Using finite element analysis, the Disney team found this room was safe, even for people with pacemakers and other implanted electronics. The team successfully installed lamps, fans, and a remote-controlled car in this room, all powered wirelessly with three coils oriented orthogonally to each other. The discussion goes on to mention this setup can be used to charge mobile phones, although we’re not sure if charging a phone in a Faraday cage makes sense.

    If the project from Disney research isn’t enough, here’s the MotherBox, a completely unrelated Indiegogo campaign that was launched this week. This isn’t just any crowdfunding campaign; this work comes straight out of Columbia University and has been certified by Arrow Electronics. This is, by all accounts, a legitimate thing.

    https://www.indiegogo.com/projects/the-motherbox-true-wireless-charging-power-phone–2

    Reply
  29. Tomi Engdahl says:

    Wireless charging is becoming a basic feature in many portable device. Barcelona MWC trade show Semtech presents a solution in which a single transmitter can wirelessly charge many devices at the same time.

    Analog and mixed-signal circuits from the Semtechin wireless charging technology is called LinkCharge. The company even sells kits that consumers can work on

    LinkCharge Semtechin technique utilizes a proprietary protocol to connect the transmitter and the receiver. Electrical power is transferred using induction, so there is nothing extraordinary.

    Semtechin platform rechargeable devices can be set freely. Beginning to produce one watt of power charging

    Source: http://www.etn.fi/index.php/13-news/5933-langattomasti-virtaa-usealle-laitteelle

    Reply
  30. Tomi Engdahl says:

    Sony Patent Could Let You Wirelessly Charge Your Phone From Another Device
    https://yro.slashdot.org/story/17/03/16/2343224/sony-patent-could-let-you-wirelessly-charge-your-phone-from-another-device

    Sony hopes to make the process of wireless charging a bit easier as it has applied for a patent that will allow you to wirelessly charge your phone straight from someone else’s phone.

    Sony’s new wireless charging patent could let you borrow juice from other devices
    http://www.digitaltrends.com/mobile/sony-wireless-charging-patent/

    With Sony’s new tech, you could essentially just “steal” power from a friend who might have a slightly more charged up device than you.

    The patent filling itself was discovered by What Future, and the report notes that the tech may not be limited to phones. Instead, Sony could apply it to things like fridges, microwaves, TVs, computers, and really any kind of electronic device. The idea here is that all of you home devices could eventually become sources of wireless energy — so your phone will almost always be charging if you’re at home, without the need for wires.

    This isn’t the first time we’ve seen patents and patent fillings related to new wireless charging techniques.

    Reply
  31. Tomi Engdahl says:

    11 Myths About Magnetic-Resonance Wireless Charging
    http://www.electronicdesign.com/power/11-myths-about-magnetic-resonance-wireless-charging?NL=ED-003&Issue=ED-003_20170530_ED-003_769&sfvc4enews=42&cl=article_1&utm_rid=CPG05000002750211&utm_campaign=11311&utm_medium=email&elq2=826aee02f3b94cd7908dc85c53a7d8d0

    While the possibilities of magnetic-resonance-based wireless charging are very exciting, the technology is frequently misunderstood by those not involved in the industry.

    Consider the devices we use every day: From smartphones and smartwatches and potentially electric vehicles, electronics are becoming as mobile as people themselves. We rely and expect our devices to be charged at all times, ready-to-use when needed. But as it currently stands, we still must plug in our phones, our electric cars, and our smartwatches, tethering us to cords and cables, triggering range anxiety and obsessing about the remaining juice on our devices.

    Wouldn’t it be nice instead to have a user experience where our electronics are charged autonomously and seamlessly, without any conscious human intervention, even while our devices are in use?

    While wireless charging is not a new concept, the industry has been fluctuating over the past decade or so as different forms of the technology enter the arena, all promising to eliminate the last tether. However, those excited for what’s to come are left confused in terms of what is wireless charging reality and what is just a myth.

    Inductive—the first generation of wireless-charging technology—was very limiting, providing only low power transfer and almost zero spatial freedom.

    Magnetic resonance is another—and the most promising—form of wireless power as it moves beyond form-factor restrictions and allows for charging over distance, efficiently and safely. It can also be applied to a wide range of applications because of these qualities.

    However, while the possibilities of magnetic resonance are very exciting, the technology is frequently misunderstood by those not involved in the industry.

    1. Magnetic resonance offers a poor user experience.

    Magnetic resonance offers significant user benefits compared to the first generation of inductive-charging technology. Products on the market today charged via inductive require the device to be in direct contact with the source.

    2. Magnetic resonance is inefficient and slow.

    Magnetic resonance can satisfy the charging needs of devices for a wide range of applications, from a wearable to an electric car.

    Well-designed magnetic resonance systems are very efficient, too. For example, electric vehicles enabled by this technology can achieve efficiencies as high as 94%, the same efficiency that can be achieved via state-of-the-art wired solutions. The Airfuel Alliance is the body that oversees magnetic-resonance technology to ensure these standards are being met.

    3. Magnetic resonance isn’t safe.

    A common misconception about magnetic-resonance technology is that it’s not safe.
    In reality, the relatively low-frequency electric and magnetic fields of a magnetic-resonance system design are kept below established and long-standing human safety limits (often specified by global regulatory bodies such as the ICNIRP and FCC).

    4. Magnetic resonance causes damage to products with RFID.

    To properly function, RFID devices use magnetic fields. Consequently, RFID tags may be damaged when exposed to magnetic fields of the strength used for wireless energy transfer. Given this, magnetic-resonance systems are available that detect the presence of RFID tags and provide user notification so that corrective action can be taken. The AirFuel Alliance resonant standard is incorporating and evolving this functionality to ensure that basic safety functionality is built into all products.

    5. Magnetic resonance can’t be used in products with metal housings.

    Many people assume that magnetic resonance can’t be embedded in products that are either built with, or have, a metal case, because the metal blocks electromagnetic fields and currents induced in the metal may cause it to heat up. This isn’t true, though. The AirFuel Alliance utilizes electromagnetic waves at 6.78 MHz, which will not heat up most common metal objects, even those in close quarters to the device like coins or car keys.

    6. Magnetic resonance is so complex, it requires a PhD to build into a product.

    Product integration of new technology is always complicated, and magnetic resonance used to be no exception. However, the maturity of industry standards via the Airfuel Alliance and the availability of purpose-built ASICs and associated market reference designs

    7. Magnetic resonance is expensive for designers to embed into products.

    Early implementations of magnetic resonance based on off-the-shelf parts were not ideal for product companies from cost and size perspectives. However, purpose-built ASICs for magnetic resonance on the market today simplify the product integration and reduce the overall bill-of-materials cost for both the transmitter and receiver sides.

    8. Magnetic resonance only works for my consumer electronics, and no other electronics.

    For example, a magnetic-resonance system can send 11 kW of power to charge electric vehicles.

    9. Magnetic-resonance sources are always charging pads.

    Wireless charging traditionally required a source that sends the power to the device.
    Source resonators can be implemented on thin, flexible printed-circuit boards or formed into three-dimensional shapes to create a “charging volume.”

    10. Magnetic resonance will make my product design bulkier and heavier.

    Resonators for magnetic resonance can be fabricated on thin, flexible circuit boards, minimizing impact to the overall device shape and design.

    11. Magnetic-resonance-enabled devices won’t penetrate my life anytime soon.

    In fact, the first product enabled by magnetic resonance will be hitting the market this year, starting this spring with the Dell Latitude 7285, the industry’s first 2-in-1 laptop to enable a workspace free of wires.

    Reply
  32. Tomi Engdahl says:

    Paul Miller / The Verge:
    Upcoming iPhones will offer wireless charging, says CEO of Apple manufacturer Wistron

    The next iPhone will have wireless charging, according to Apple supplier
    https://www.theverge.com/circuitbreaker/2017/6/14/15802888/iphone-7s-8-rumor-leak-wireless-apple-supplier-wistron

    Plugging things in is no fun, especially when a certain company refuses to embrace industry-standard plugs. Wireless charging is an obvious solution, which has been embraced by many Android manufacturers but has remained conspicuously absent from the iPhone. That might be about to change.

    Wistron is a manufacturer in India, which Apple recently added to its roster to increase market share in the country and bring prices down. On Wednesday, Wistron’s CEO Robert Hwang told reporters that the next generation of iPhones will include “new features like waterproof and wireless charging.”

    Reply
  33. Tomi Engdahl says:

    Major advance in wireless charging
    https://www.youtube.com/watch?v=7nkOgiTxfEs&feature=youtu.be

    Stanford University scientists have overcome a significant hurdle in the wireless charging of electric vehicles. The researchers developed a system that wirelessly delivers electricity to a nearby moving object. The technology, known as magnetic resonance coupling, could be used to charge electric vehicles as they drive along the highway and personal devices, like medical implants and cellphones, at close range.

    In this video, Stanford Professor Shanhui Fan and graduate student Sid Assawaworrarit explain the researched published on June 15, 2017, in the journal Nature.

    Wireless charging of moving electric vehicles overcomes major hurdle
    https://energy.stanford.edu/news/wireless-charging-moving-electric-vehicles-overcomes-major-hurdle

    Reply
  34. Tomi Engdahl says:

    Apple Goes Cord-Cutting with the iPhone 8
    Wistron, an iPhone assembler, confirmed that wireless charging will be incorporated into its upcoming model.
    http://www.electronicdesign.com/power/apple-goes-cord-cutting-iphone-8?NL=ED-003&Issue=ED-003_20170628_ED-003_917&sfvc4enews=42&cl=article_2_b&utm_rid=CPG05000002750211&utm_campaign=11791&utm_medium=email&elq2=ea0efa25235b4ac6b8e75c3276151ee0

    Wireless charging has been a common feature in Android phones like the Samsung Galaxy series for a few years. New reports suggest that the iPhone 8 also will incorporate wireless charging technology. “The assembly process for the previous generations of smartphones have not changed much,” said Robert Hwang, CEO of the India-based Apple supplier Wistron, “though new features like waterproof and wireless charging now require some different testing, and the waterproofing will alter the assembly process a bit.” It appears that Wistron is trying to figure out how to add wireless charging to its assembly process.

    Maybe Apple will not bundle a wireless charger with every model or perhaps it will limit it to the higher-capacity SKUs. It has been suggested that Apple will use a wireless long-range charging technology without the need for a charging pad.

    It remains unclear which wireless charging standard Apple will support. Earlier this year, Apple joined the Wireless Power Consortium, which backs the Qi standard. But that doesn’t mean it will support only Qi. If it does, however, this will definitely help to solidify the Qi standard. One hope is that Apple offers a dual-mode charging option. Even though it could be more expensive to produce a phone that supports both standards, such flexibility would certainly benefit consumers.

    Among the companies that stand to benefit from the iPhone’s potential shift to wireless charging are chipmakers like Broadcom and Integrated Device Technology.

    If the latest rumors are true, the demand for wireless charger technology will create significant growth for the wireless charging market.

    Reply
  35. Tomi Engdahl says:

    Electronics in Europe Update
    http://www.eetimes.com/author.asp?section_id=36&doc_id=1332015&amp;

    An update from Wireless Power Congress and PCIM’s call for papers from our European correspondent.

    Last week we went to the Wireless Power Congress (www.wireless-power-congress.com) in Munich, and got a look at the commercialization level of penetration in the wireless power area.

    Reply
  36. Tomi Engdahl says:

    Darrell Etherington / TechCrunch:
    Apple unveils AirPower wireless charging pad for iPhone 8/8+/X, Apple Watch, and AirPods with new charging case, coming in 2018

    Apple reveals AirPower wireless charging pad coming in 2018
    https://techcrunch.com/2017/09/12/apple-reveals-airpower-wireless-charging-pad-coming-in-2018/

    Apple has a new wireless charging pad called the AirPower, which is essentially a mat with room for your new iPhone 8 or iPhone X, as well as your Apple Watch, and even AirPods with a new optional wireless charging case accessory. It’ll charge all of them without any cables required, but you’ll have to wait until 2018 to get one – Apple said it’s coming early next year.

    The AirPower mat uses a new kind of charging standard that supports multi-device charging, which might explain why it’s not shipping right away: It probably requires more work to bring it to full scale production, which is actually something that was reported as a rumor earlier today prior to this event.

    Mitchel Broussard / MacRumors:
    Apple says it’s partnered with Mophie, Belkin, Incipio, and more on wireless charging accessories for iPhone 8, 8 Plus, and X

    Apple Confirms iPhone Wireless Charging Accessories Coming from Mophie, Belkin, and More
    https://www.macrumors.com/2017/09/12/apple-confirms-iphone-wireless-charging-accessories-coming-from-mophie-belkin-and-more/

    Apple today revealed the iPhone 8, iPhone 8 Plus, and iPhone X, all of which will support Qi wireless charging. Although Apple’s own wireless charging accessory won’t be coming out for a while, customers will be able to purchase charging pads from other accessory makers: Mophie, Belkin, Incipio, and more.

    The iPhone’s charging is based on the Qi standard, so users will be able to charge their iPhones anywhere they can find a Qi charging pad.

    Reply
  37. Tomi Engdahl says:

    Wireless receiver suits mobile devices
    http://www.edn.com/electronics-products/other/4458819/Wireless-receiver-suits-mobile-devices

    A wireless power receiver, the MAX77950 from Maxim, operates as a transmitter in PeerPower mode to enable peer device power transfer through in-band ASK communications. The dual-mode receiver uses near-field magnetic induction when coupled with a WPC or PMA transmitter and provides output power of up to 12 W. Additionally, a small wafer-level package makes the MAX77950 well-suited for wearable and mobile applications, including headsets, smartphones, smart watches, and portable medical devices.

    MAX77950
    WPC/PMA Dual Mode Wireless Power Receiver
    WPC/PMA Dual Mode Wireless Power Receiver for Mobile
    https://www.maximintegrated.com/en/products/power/battery-management/MAX77950.html/tb_tab0

    Reply
  38. Tomi Engdahl says:

    Data and electricity in the same wireless link

    Wireless charging is gaining momentum

    Researchers are co-chaired by Associate Professor David Ricketts in an EEE Antennas and Wireless Propagation Letters article where the same 13.56 megahertz radio link is used for both charging the tablet at about three watts and for data transfer at 3.39 megabytes per second.

    In the test, the tablet and the charging tray were 16 centimeters apart. The key to innovation is not so much the data rate but the fact that the wireless download link can also be broadband. This opens significant new opportunities for research.

    Until now, it has been thought that magnetic field-based wireless transmission – that is, all current charging techniques – requires very narrowband antennas to minimize losses in the creation of magnetic fields.

    The Ricketts team survey found that a broader bandwidth could also be used for the transfer. The energy efficiency of the system is only 2.3 per cent, although a broader band is used, which can also relocate data relatively quickly.

    Source: http://www.etn.fi/index.php/13-news/6858-dataa-ja-saehkoeae-samassa-langattomassa-linkissae

    Reply
  39. Tomi Engdahl says:

    Pi wants to extend the reach of wireless charging
    https://techcrunch.com/2017/09/18/pi-wants-to-extend-the-reach-of-wireless-charging/

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    September 18 – 20, 2017 | Pier 48, San Francisco, CA

    Pi wants to extend the reach of wireless charging
    Posted Sep 18, 2017 by Greg Kumparak (@grg)

    Wireless charging isn’t new — but with the new iPhones picking it up as a feature, it’s about to get a huge boost in visibility.

    But wireless charging is still pretty limited, particularly in terms of where your device can be while pulling a charge. For the most part, “wireless charger” means “a pad you sit your device directly on.” Lift your phone a few centimeters off the pad, and charging stops.

    Pi, a company that debuted in the TechCrunch Disrupt Battlefield this afternoon, wants to change that. It’s building a device — the aptly named Pi Charger — that they say can charge multiple devices within about a foot in any direction. It’s not the full-room charging concept that other companies have spent years trying to tackle, but it provides a good bit more flexibility over a pad.

    The team says they’re using resonant induction here, or the same underlying concept that powers the Qi charging standard found in the new iPhones and many an Android phone. Their secret sauce, according to co-founder John Macdonald, is a beam-forming algorithm that lets them safely direct a magnetic field to wherever the device is sitting.

    Reply
  40. Tomi Engdahl says:

    Wireless receiver suits mobile devices
    https://www.edn.com/electronics-products/other/4458819/Wireless-receiver-suits-mobile-devices

    A wireless power receiver, the MAX77950 from Maxim, operates as a transmitter in PeerPower mode to enable peer device power transfer through in-band ASK communications. The dual-mode receiver uses near-field magnetic induction when coupled with a WPC or PMA transmitter and provides output power of up to 12 W. Additionally, a small wafer-level package makes the MAX77950 well-suited for wearable and mobile applications, including headsets, smartphones, smart watches, and portable medical devices.

    Reply
  41. Tomi Engdahl says:

    BMW is set to offer a pad to wirelessly charge your car
    But it’s not coming to the US — yet
    https://www.theverge.com/2017/9/25/16363038/bmw-wireless-charging-pad-for-cars-530e

    BMW is close to rolling out wireless charging on one of its cars — and this time, it doesn’t involve phones. That feature is already there, but being able to wirelessly charge your car is new.

    It really is a big charging pad for a 530e iPerformance plug-in hybrid. The BMW pad connects to a 220-volt outlet, then the sensors on the car show you where to steer so the vehicle can communicate with the charger, as shown in this video.

    According to BMW, the 9.4kWh battery in the 530e can be charged in about 3.5 hours at 3.2kW of power, or close to the level you’d get if you just plugged the car in with a cord.

    In other countries, BMW plans to launch the wireless charging system early next year, but only on the 530e iPerformance plug-in hybrid sedan.

    Reply
  42. Tomi Engdahl says:

    Preparing for (and Profiting from) Apple’s Wireless World
    http://www.electronicdesign.com/power/preparing-and-profiting-apple-s-wireless-world?NL=ED-003&Issue=ED-003_20170925_ED-003_304&sfvc4enews=42&cl=article_1_b&utm_rid=CPG05000002750211&utm_campaign=13165&utm_medium=email&elq2=837b0d9d788342eaa2113e01caeb7ae6

    As Apple goes wireless with its latest iPhone, here are some tips and answers to questions you may be asking yourself.

    Having been involved with the wireless power industry since before the first mobile phone adopted wireless charging and before the Qi or AirFuel standards existed, here I hope to provide some clarity and tips to companies looking to capitalize on the opportunity that Apple is magnifying.

    Apple’s adoption of wireless power in the new iPhone will amplify the demand for public charging points.

    Some companies like Chargifi and AirCharge are providing mobile apps that show people where their nearest wireless charging stations are located. Chargifi has found that the average charging session on their network is 43 minutes and 17 seconds.

    . However, there has been some apprehension for a wide-scale rollout due to uncertainty over wireless power standards. Apple’s decision to join the Qi standard ends the debate. Wireless power adds safety, convenience, and one-handed drop-and-go charging versus two-handed plug and un-plug operation. Wireless charging removes potentially dangerous cords from the car’s cabin and it lends naturally to consumer behavior to place phones in the center console or cup holder—now with the benefit of charging their device while doing so. I believe that wireless power will become nearly as ubiquitous as cup holders inside of vehicles.

    Reply
  43. Tomi Engdahl says:

    Ikea is roasting Apple for overpriced charging mats
    http://mashable.com/2017/09/26/ikea-apple-roast/#iSwf7z9A6sqU

    Ikea started a new ad campaign for their wireless charging devices in response to Apple’s launch of the iPhone X and iPhone 8 and their “new” wireless charging pads.

    Reply
  44. Tomi Engdahl says:

    Rectenna Serves 2.45-GHz Wireless Power Transmission
    http://www.mwrf.com/systems/rectenna-serves-245-ghz-wireless-power-transmission?code=UM_Classics09217&utm_rid=CPG05000002750211&utm_campaign=13148&utm_medium=email&elq2=f7e28b17668346a58e72a72d27619f29

    This fairly simple and straightforward rectenna design can be applied for conversion of energy at RF/microwave frequencies to usable DC power.

    Wireless applications inject a great deal of excess electromagnetic (EM) energy into the environment—energy which can be reused if properly recovered. A rectifying antenna, or rectenna as it is popularly known, is one such means for recovering that energy. In order to demonstrate the capabilities of such a design, a novel rectenna was developed for low-power operation at a single Industrial-Scientific-Medical (ISM) frequency of 2.45 GHz.

    The rectenna consists of a highly efficient photonic-band-gap (PBG) structure, a microstrip lowpass filter (LPF) with defected ground structure (DGS) circuitry, and a Schottky diode. To evaluate the rectenna, it was fabricated on a low-cost FR-4 printed-circuit-board (PCB) material with relative dielectric constant (εr) of 4.4 in the z-direction at 10 GHz and thickness of 1 mm. As will be shown, the rectenna achieves RF-to-DC conversion efficiency of 63% when processing received power of +18 dBm at 2.45 GHz.

    A rectenna is an antenna with additional components, including a LPF and a rectifying circuit. The rectenna receives microwave energy from the antenna.4-6 A Schottky rectifier diode converts the received RF energy to DC power.7-9 The amount of power that can be transmitted is limited, and the amount of RF/microwave power is reduced from the source through attenuation, mainly due to free-space signal path loss. For use in portable devices which, in generally, usually have small dimensions, an effective rectenna design should also have small dimensions.

    The commercial Schottky diode chosen for use in the rectenna design was a model HSMS-286C from Avago Technologies. This is a compact lead-free, surface-mount semiconductor that is usable from 915 MHz to 5.8 GHz. It features high detection sensitivity of as good as 50 mV/μW at 915 MHz, 35 mV/μW at 2.45 GHz, and 25 mV/μW at 5.8 GHz. The miniature surface-mount package helps save PCB space.In the rectenna design, the purpose of the rectifier is to directly convert RF/microwave energy into DC electrical energy.

    The rectenna with PBG antenna operating at the single ISM-band frequency of 2.45 GHz represents a fairly simple design and an effective means of converting RF signals to DC energy at that frequency. The gain of the rectenna is 4.29 dBi at 2.45 GHz, with RF-to-DC conversion efficiency of as high as 63%. This particular rectenna design can operate effectively with low-power loads at these ISM frequencies using a low-cost LED to aid in the conversion.

    Reply

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