| 摘要 |
The d.c.supply circuit contains a series-circuit, as usual, composed of a switch (T) and an inductivity (L). A regulator circuit (RS) is provided to alternatingly drive switch (T) into the conductive and nonconductive state. Said control is performed by the inductivity (L) and responsive to current (iL). According to the invention, the series-circuit comprises an auxiliary switch (TH), to which a seriescircuit formed of a diode (15) and a capacitor (16) is parallel-connected in series. In short periods, in which switch (T) is conductive, while auxiliary switch (TH) is nonconductive, said capacitor (16) is charged in order to generate the supply voltage (UH) for the regulator circuit (RS). (Fig. 1). |
