| 摘要 |
An electrical supply device comprises a transformer (T) with a secondary winding (T2) to feed a current to a load (L), control circuitry (18, 22, 24; R12) for the device and an auxiliary supply source (50) for said control circuitry (18, 22, 24; R12). The auxiliary supply source (50) includes at least one output capacitor (Cp) across which a supply voltage is provided for said control circuitry (18, 22, 24; R12), as well as at least one charge accumulation capacitor (Cp3; Cp1; Cp2) adapted to be traversed by the current fed to said load (L). Moreover, there are included a comparator (53) sensitive to the voltage on said at least one charge accumulation capacitor (Cp3; Cp2), and a switch (52), interposed between said at least one charge accumulation capacitor (Cp3; Cp1; Cp2) and said output capacitor (Cp). Said switch (52) is coupled to comparator (52) whereby, when the voltage on said at least one charge accumulation capacitor (Cp3; Cp2) reaches a reference level, said switch (52) couples said charge accumulation capacitor(s) (Cp3; Cp1; Cp2) to said output capacitor (Cp) by transferring onto said output capacitor (Cp) the charge on said at least one charge accumulation capacitor (Cp3; Cp1, Cp2). |
