| 摘要 |
What is disclosed is a switched-mode power supply for supplying a DC-fed load (LD) by a stepped-up, stabilized DC voltage (uzw), which is formed from an AC mains voltage (U) by means of a rectifier circuit (D1 to D4), a charging inductor (L1), a switch (V1), which is controlled by a control unit (2) and has its switching path connected in parallel with outputs of the rectifier circuit, and also a charge storage arrangement (D5, C1, C2, D6), which is connected once again in parallel with the switching path of the said switch. In this case, the charge storage arrangement (D5, C1, C2, D6) comprises a series circuit of charging diodes (D5 and D6) and two storage capacitors (C1, C2), whose common junction point is connected to a neutral conductor terminal (N) of the rectifier circuit. The charging inductor (L1) is arranged in the line path, at high potential (L), between AC mains voltage (U) and the rectifier circuit and has an auxiliary winding (L1s), to which a signal evaluation unit (3) for the floating evaluation of the instantaneous charge state of the charging inductor is connected, in order to derive therefrom state control signals (Ul1, Ust, Io) for the control unit (2). |
