AC-DC converter with a smoothing circuit achieving small current ripples at the converter output

摘要

An AC-DC converter with a smoothing circuit is provided with an AC power source (301), a rectifier (302), connected to the AC power source (301), a controller (304) for controlling conversion of DC voltage, connected to the rectifier (302) via a positive and a negative pole line L1,L2. The controller (304) has an operating voltage between A1 and D. A source of a DC voltage (308) above A1 is present in the converter. A capacitor (402) is connected across the positive and negative pole of the source of a DC voltage (308). The capacitor (402) feeds the controller (304) via the L1 and L2 lines. The capacitor (402) can only be charged by voltage other than the voltage output by the rectifier (302) and has a capacitance such that only voltage above A1 is supplied to the controller (304).