How chargers with Qi charging technology work
With Qi technology, a resonant inductive coupling is established between the transmitter (charging station) and receiver (smartphone). The charger sends out a check signal at regular intervals, which uses changes in capacity or resonance to determine whether a smartphone or other device to be charged is on the charger.
If a corresponding product is placed on the charging station, it modulates the charge and checks the compatibility of the mobile device with the Qi standard. If the mobile device is compatible, the charging process is started.