Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
In a single switch, forward (buck), transformer-coupled switching regulator, it is necessary to provide a mechanism to reset transformer core flux during the OFF time of the switching device to avoid core saturation and to limit the peak voltage seen by the switch. A demagnetization winding on the transformer with a series diode or a resistor/capacitor/diode dissipative clamp circuit can be used, but impose limitations on duty cycle range or dissipate magnetization and leakage energy stored in the transformer during the ON time. Also, these approaches limit the allowable core flux excursions to the difference between remanance and saturation, requiring a larger core for a given ON volt-time. Fig.