Wireless power charging was a big point of discussion with a number of different solutions on the APEC 2018 exhibit floor. The following wireless charging solutions had unique aspects in their strategies; let’s take a look at what I saw over the last few days.

Efficient Power Conversion (EPC)

The first exhibit I visited was Alex Lidow’s EPC offering for wireless power, which was the most interesting and useful to me as an engineer as well as a consumer. EPC’s Michael de Rooij has managed to design a very practical coil configuration (Figure 3) that can be integrated into or under a desk, table, or any flat surface like behind a living room sheetrock wall where a flat-screen TV is mounted, except there will be no power plug needed. This design architecture is not sensitive to position as much as many other designs out there, where you need to place a phone or smartwatch in a very specific targeted area (Figure 1).


Figure 1 Here is a desktop example of how EPC’s wireless power architecture is most practical and not sensitive to positioning of your smart phone, watch, AI, or other most-used portable, battery-operated products. (Image courtesy of Loretta Taranovich)

First of all, I really love that EPC has the best educational offerings for designers who need to understand the concepts and tradeoffs in wireless power. Michael de Rooij’s ‘textbook’ entitled ‘Wireless Power Handbook’ is the best tutorial I have seen out there in the industry for designers and others interested in understanding the different aspects of this technology. The author is a talented engineer creating practical wireless power demos and evaluation boards/reference designs for EPC so that designers can start building real-world solutions (Figure 2).


Figure 2 You can see the ‘Wireless Power Handbook’ by Michael de Rooij in the lower left foreground on the table at EPC’s APEC booth. (Image courtesy of Loretta Taranovich)

Regarding standards, AirFuel has superior use case and technology, but Apple is behind Qi, so I believe that AirFuel will emerge and co-exist with the Qi standard.

EPC offers development boards and eGaN products with a wide power range for both the transmit and receive sides of a wireless power transfer system. In the EPC video below, you'll see the use of eGaN products in the common AirFuel and Qi standard systems, including a multi-mode system that can operate in accordance with either standard. In addition to EPC demonstrations, several customers, such as WiTricity, Solace Power, and Gill Electronics wireless power end products are presented.

Learn more about how they do it here. EPC partners with some of the industry’s key companies to enable wireless power and make it ubiquitous.

Michael de Rooij's very unique transmit board design with a series of interconnected coils can be seen in Figure 3.


Figure 3 Dr. Alex Lidow, EPC CEO and co-founder, shows a functional power transmit board coil design for wide area coverage. (Image courtesy of EPC)


Figure 4 Lidow’s mantra to the industry is "Cut the cord!" (Image courtesy of Loretta Taranovich)

EPC is using a magnetic resonance technique, which they think this is the way to go.


Figure 5 EPC’s GaN and creative reference designs make wireless power a reality (Image courtesy of Loretta Taranovich)

[Continue reading on EDN US: Wireless charging options from Analog Devices, Infineon & STMicroelectronics]

Steve Taranovich is a senior technical editor at EDN with 45 years of experience in the electronics industry.

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