CONTROL METHOD AND CIRCUIT FOR HALF-BRIDGE-CONNECTED DC CONVERTER

摘要

A control circuit (K1, B4) for a half-bridge switched-mode current-mode- controlled DC converter measures a primary current of a main transformer (T) of a half bridge (M1, M2, C1, C2) and controls (B3) conduction times of the switches (M1, M2) on the primary side on the basis of a voltage feedback (VF) and the measured primary current (lcs). The control circuit (B1, B2) causes to the measured primary current (lcs) a correction (Im - Ib) which is proportional to the deviation of an input voltage (Vm) of the half bridge from half of the input voltage (Vm) of the half bridge and which affects the conduction times of the switches (M1, M2) on the primary side in such a way that the deviation of the half voltage is compensated for.