DC to DC Flyback Converter

The flyback converter is a DC to DC buck-boost type converter with galvanic isolation. A flyback converter stores energy as a magnetic field in the inductor air gap during the time the converter switching element (transistor) is conducting. When the switch turns off, the stored magnetic field collapses and the energy is transferred to the output of the flyback converter as electric current. The flyback converter can be viewed as two inductors sharing a common core with opposite polarity windings. The voltage conversion ratio is (ns/np)×(D/(1-D)) where D is the duty cycle of the mosfet ns is the secondary turns and np is the primary turns of the transformer. In the example we have set the duty cycle at 50% and the ratio of ns/np is equal to 2 so with 50V in the input we expect that after the transients settle out to have 100V at the output. If you want to change the duty cycle just change the width of all voltage pulse sources (5% is 50% duty cycle and 10% is 100% duty cycle).

published 10 years ago