Patent ID: 7859861

Claim:
An insulated power transfer device connected to an output load connected between a first output terminal and a second output terminal, comprising a DC voltage source and a magnetic coupler comprising a transformer with a primary winding between two primary terminals, a secondary winding in series with a coupling inductance between two secondary terminals, said coupling inductance comprising at least the leakage inductance of the transformer; a rectifier bridge comprising two diodes, each diode connected between a respective secondary terminal and the first output terminal, and two controlled switches, each controlled switch being connected between a respective secondary terminal and the second output terminal, and a secondary controller of said controlled switches able to set them simultaneously to the closed state for an energy storage time, and comprising on the primary side a voltage step-up circuit comprising: an input inductance in series with the DC voltage source; an active buffer stage in parallel with the series assembly formed by the input voltage source and the series inductance, said stage comprising a controlled switch with a peak-clipping diode in parallel, connected in series with a capacitor, said switch being connected to the inductance and said capacitor at the source, a first and a second pair of controlled switches in series, each pair connected in parallel with the active buffer stage and the connection point between the two switches of each pair being linked to a respective primary terminal, and a primary controller of the switches of said pairs able to set them simultaneously to the closed state for an energy storage time, to short circuit the inductance on the input voltage source, and in that the primary and secondary controllers provide independent regulation, the primary controller controlling the energy storage time on the primary to regulate the voltage at the terminals of the capacitor of the active buffer stage at a peak input voltage value, and the secondary controller controlling the energy storage time on the secondary to regulate the output voltage.