Q-FACTOR CONTINUOUS EXCITATION METHOD AND APPARATUS

A method is provided for operating a wireless charger having a multi-switch inverter which supplies an output PWM signal to a resonant circuit in response to switching control signals, including a first set of continuous excitation phase switching control signals (which generate the output PWM signal to have alternating positive and negative pulses having a first pulse frequency) and a second set of free resonance signal sensing phase switching control signals (which enable the resonant tank circuit to generate a resonant decaying output voltage signal in the presence of a foreign object that is located near the wireless charger), where each continuous excitation phase switching control signal includes a plurality of positive or negative excitation pulses having the first pulse frequency, and where one or more quality factor parameters of the wireless charger are measured based on one or more electrical parameters of the resonant decaying output voltage signal.