Wi-Charge, a wireless charging company from Israel, has demonstrated a light-based charger at the Mobile World Congress. Along with other few existing wireless charging methods, the Wi-Charge method of charging provides an alternative to support background charging across longer distances compared to those offered by existing rivals. Wi-Charge develops receivers and transmitters that utilize laser light for charging a wide range of devices. The transmitters are typically shaped to fit into wall or light bulb sockets and provide a constant charge. Incidentally, these devices do not operate with infrared light as do some other makes of chargers, and therefore, do not produce unsafe radiation.
The charging system developed by Wi-Charge is called the distributed resonator. It consists of a high-power light source focused with two retro reflective mirrors, very similar to reflectors typically used on a bicycle. One of the mirrors focuses the laser transmitter and the other has a photovoltaic cell at its focal point at the receiving end. This way, Wi-Charge has a closed loop system that prevents the ultra-high energy to stray and enter the human body.
The distributed resonator charging device transmitter supports multiple devices. The total number of charging devices ultimately depends on the battery size being charged. The smart home device, which Wi-Charge will release first in the market, will come with a receiver module capable of charging up to 2W with a plug-in transmitter capable of covering a room 15-foot long.
Another model, meant for charging mobile devices, measures 17x17mm and has a transmitter capable of delivering 10W. The model has two receivers capable of charging devices at 5W each. Wi-Charge demonstrated this by charging a Samsung Galaxy S4 at the end of a 10-foot long table capable of rotating up to 80-degrees.
The basic idea behind the Wi-Charge wireless chargers is to keep devices always charged, never allowing them to drain or become empty. For this, their chargers pump in just enough power required for the device to be normally used pus a little extra.
The company has developed other form factors as well. One of their chargers is shaped like a dongle that attaches to a speaker in a phone case with an embedded receiver. Ultimately, the company plans to integrate their transmitters inside smart light bulbs.
Their plan is to integrate the receiver within the device being charged. According to their CEO, the transmitter could be embedded in the front part of the phone or even go under the glass of the screen. As the company is not competing to provide the fastest charging method, users can expect their empty devices to charge up completely within 2-3 hours.
At present, coil-based chargers dominate the wireless charging arena. That makes it a challenging proposition for Wi-Charge to enter the market. Currently, Wi-Charge is working to increase the charging distance of its transmitters to 30 feet, while reducing their size to 10x10mm.
While the consortia of inductive chargers fight each other for dominance, Wi-Charge is confident the very weak value proposition of the inductive chargers will allow their long-range power to be considered superior. Accordingly, Wi-Charge is hoping to partner with larger OEMs to drop the prices of their devices by proliferation.
