Patent ID: 10008946

Abstract:
A primary-side regulated (PSR) current control system under a LLC topology includes a voltage polarity converting circuit, a current signal sampling circuit, a current cross-over detecting circuit, a zero current detecting circuit, and a current integrator circuit. The voltage polarity converting circuit obtains a voltage signal from the primary side of a LLC transformer and outputs a positive-voltage signal, and the current integrator circuit then obtains a current input signal outputted by the current signal sampling circuit, a zero-crossing current point outputted by the current cross-over detecting circuit, and a zero current condition outputted by the zero current detecting circuit, and raises the minimum current level of the current input signal to the zero-crossing current point based on the zero-crossing current point and the zero current condition, and generate and integrate a current integration waveform to create an output current, so the LLC transformer directly obtains, at the primary side, the output current for controlling secondary-side output load conditions.