Sorry, we just need to make sure you’re not a robot. The Qi logo, which wireless charging pdf download of a round-esque, lowercase “q” with a semicircle at the right parallel to its stem and a circle on top. First released in 2008, the Qi standard had by 2016 been incorporated into more than 140 smartphones, tablets and other devices. Under the Qi specification, “low power” inductive transfers deliver power below 5 Wm using inductive coupling between two planar coils.
These coils are typically 5 mm apart but can be up to 40 mm and possibly farther apart. Regulation of the output voltage is provided by a digital control loop where the power receiver communicates with the power transmitter and requests more or less power. Communication is unidirectional from the power receiver to the power transmitter via backscatter modulation. In backscatter modulation, the power-receiver coil is loaded, changing the current draw at the power transmitter. These current changes are monitored and demodulated into the information required for the two devices to work together.
The WPC published the Qi low-power specification in August 2009. The Qi specification can be downloaded freely after registration. In 2011, the Wireless Power Consortium began to extend the Qi specification to medium power. In 2015, WPC demonstrated a high-power specification that will deliver up to 1 kW, allowing the powering of kitchen utensils among other high-power utilities. Ssangyong the second car manufacturer to offer a Qi option, also in 2013. Qi charging pad in the center console.
However, the existence of several competing wireless charging standards was still seen as a barrier to adoption. By early 2017, Qi had displaced the competing standards, with no new products featuring Rezence. Base Station, which is connected to a power source and provides inductive power, and Mobile Devices, which consume inductive power. Mobile Device contains a power receiver holding a receiving coil. Close spacing of the two coils, as well as shielding on their surfaces, ensure the inductive power transfer is efficient. Base Stations typically have a flat surface—referred to as the Interface Surface—on top of which a user can place one or more Mobile Devices.