Patent ID: 7227762
Filing Date: 2007-06-05
Classification: H01F

Abstract:
1. A fine-tuning circuit for reducing the induction voltage of a subject secondary winding of a main transformer comprising: a main transformer having a primary winding, at least one secondary winding including the subject secondary winding; an auxiliary transformer having a primary coil and a secondary coil, wherein the primary coil of the auxiliary transformer is connected with the subject secondary winding of said main transformer in series, said secondary coil of said auxiliary transformer being coupled to a clamping diode; and a voltage conversion circuit for producing an output voltage having an output capacitor for receiving an output current from said subject secondary winding of said main transformer via an output rectifier diode for each secondary winding; wherein when the output current flows through said subject secondary winding, an induction voltage is produced across the secondary coil of the auxiliary transformer and the clamping diode couples the induction voltage to the output voltage of said voltage conversion circuit, thereby reducing said induction voltage of said subject secondary winding.