Qi ( “Qi” , in honor of the term Eastern philosophy ) is a standard developed by the Wireless Power Consortium (WPC) for the induction transfer of energy up to 4 cm [1] .
| Qi | |
|---|---|
| Creator | |
| Published | |
| Official site | |
Qi equipment includes a transmitter plate (with a flat coil ) in the base (connected to a stationary power source) and a compatible receiver in a plug-in rechargeable device (also a flat coil); when used, the connected device is placed on the transmitter plate. The principle of electromagnetic induction is used between these two flat coils (similarly, for example, in transformer windings) [2] .
The Qi standard provides two options: low power - from 0 to 5 watts [3] and medium power - up to 10 watts.
Manufacturers using this standard in some of their devices: Apple , Asus , HTC , Huawei , LG Electronics , Motorola Mobility , Nokia , Samsung , Xiaomi , Sony , Yota Devices [4] . The Consortium of Wireless Electromagnetic Energy was founded in 2008 , is open and brings together various manufacturers from Asia, Europe and America. Its goal is to create a single standard for induction charging technology [5] . When the Qi standard gains popularity, public chargers are expected to appear in cafes, airports, sports arenas, etc. [3]
Qi Data Protocol
Qi includes the ability for a base station and a mobile device to use a limited data transmission system [6] . This allows you to charge and transmit information about the state of charge to the base station. Thus, the base station can adapt its work to meet the needs of the mobile device and stop its work when the mobile device is fully charged.
In the process, the initial detection occurs as a result of a deviation of a change in the capacitance or resonance of the transmitter coil. As soon as an object has been detected, the base station checks the device whether it is the Qi-compatible device that is placed on it. The base station transmits 8 bits of string data. The receiving mobile device must respond and provide a signal. The base station then sends several digital pings to check the optimal position of the mobile device. Only when the device has been checked and information is transmitted, charging will begin. During the charging process, the Qi device sends control data packets to adjust the power level and finally stop charging.
The data transfer protocol of the Qi charger is defined so that all devices can communicate correctly.
| Qi Standard Data Format | Qi Features |
|---|---|
| Data rate | 2 kbps |
| Bit coding | Bi-phase |
| Byte encoding | Start bit; 8 bits of data; - parity bit; stop bit |
| Package structure | • Preamble (> = 11 bits) • Header (1 Byte) |
The Qi standard specification is available and free [7] .
See also
- Wireless power transmission
Notes
- ↑ Energy transfer through granite .
- ↑ Qi standard wireless charger (video)
- ↑ 1 2 Global Qi Standard Powers Up Wireless Charging . Archived on April 7, 2013.
- ↑ Wireless Power Consortium Members . Archived on April 7, 2013.
- ↑ Qi prototypes . Archived on April 7, 2013.
- ↑ Ian Poole. Qi data protocol .
- ↑ Download Qi specification (requires registration for membership in the consortium) .