While there's been a surge in wireless charging stations armed with coils, the technology is still actively in development. Where many current wireless chargers utilize electromagnetic induction or magnetic resonance, there are some who are looking to unconventional methods to achieve safer, more convenient results.
One such method? Use infrared to power devices from a distance.
AAC's Gary Elinoff had the chance to speak with Yuval Boger, Chief Marketing Officer at Wi-Charge, about their ambitions to change the wireless charging game entirely.
Image altered from Wi-Charge
Infrared Wireless Charging
Wi-Charge has prepared a case for why IR wireless charging is both safe and efficient compared to charging via radio frequency waves (including a webinar on the subject). In addition to having more consistent charging capabilities over distance (compared to RF, which decreases with the square of the distance), IR also does not interfere with cellular, Wi-Fi, or Bluetooth.
"[Infrared] is much more concentrated than the sun," says Boger. "It's a very precise pinpoint targeting of energy."
So how does it work?
"Our power source—we call it a transmitter—scans the room with low energy, finds a Wi-Charge receiver, and then initiates this energy transfer. And the nice thing about it is that 100% of the energy that we're sending reaches the receiver, meaning that even if you're a few millimeters away from it, you're not going to see anything—you're not going to feel anything. You're just going to be happy that the device next to you is receiving energy."
The LIGHTS transmitter can be placed on the ceiling and divide its power to charge three client devices simultaneously. Image from Wi-Charge
The LIGHTS 3W System from Wi-Charge delivers up to three watts of power over 15 feet.
Wireless charging devices typically require close proximity between transmitter and receiver. Then, a very precise device-to device orientation is necessary. Not so with infrared.
It’s an idea that’s so simple at its core that makes you wonder why no one else thought of it before. Unlike RF, which propagates in all directions, infrared beams stay tight. At 15 feet, the 3-watt beam from the LIGHTS TX-3W transmitter lands on an area of about 0.25 in2. There, the LIGHTS RX-1.5W receiver sports a solar cell optimized for infrared to convert it back into electricity.
Changing Power Electronics Design for the IoT
"Forgive the hyperbole," Boger says, "but we sometimes call it the future of power." But he goes on to say that looking at the future of power requires an understanding of the present situation for power.
"Forgive the hyperbole but we sometimes call it the future of power."
Boger's first thought when looking at the present state of power is to talk about designers. "Right now, if you're designing a product," he says, "you've got to decide how it's going to get power. You can power it through batteries, but they only give you a limited amount of energy. This means that you're likely leaving out a lot of functionality that you'd like but just can't support [through] batteries. You also have an environmental concern when you dispose of them because you need to replace them every now and then."
This set of concerns will be very familiar to many designers. Indeed, the wide adoption of wireless charging technology has the potential to usher in a paradigm shift in designing for the IoT. Currently, engineers obsess on designing ultra-low-powered IoT components—because they have to. Demand continues to grow for wireless devices that allow greater freedom of movement but can still function at the same power specs as wired devices. This is because most people will agree with Boger when he says "life's better without wires." Except, perhaps, for a harried design engineer.
An example of a Google Home Mini that has been converted into a wireless device. Image from Wi-Charge
For devices that are already completed, Wi-Charge offers a Wireless Power Kit, which is designed to turn a wired device into a wireless one.
Safety and Regulation
Unless you’re a smartphone, three watts isn’t a whole lot of power, but Wi-Charge makes sure that the only place it hits is the designated target. The TX-3W starts off with an infinitesimal amount of power in search mode, looking for the RX-15W receiver, wherever it is. Only once it finds its target does the 3-watt output energize.
If anything (including pets or people) gets between the transmitter and the receiver, the beam turns off instantly. It then goes back into search mode. As soon as the obstacle is gone, the transmitter rediscovers the receiver, and the juice begins to flow again.
For their efforts, Wi-Charge has earned international, US, and Canadian UL and Class 1 laser safety certifications for the LIGHTS-3W system.
With these regulatory requirements met, Wi-Charge is posed for introduction to global markets, including the US, Europe, Japan, and China.
Wi-Charge believes that it has struck upon something that could revolutionize wireless charging design.
Have you built a wireless charging system before? What's your take on IR wireless charging? Share your thoughts in the comments below.