Fly Back Converter
In fly back converter an inductor is used is primary winding of transformer.
Inductor stores the energy when unregulated DC input is given to the circuit with turning ON the transistor Q. In this condition a voltage appears across the primary of transformer. Due to this voltage an indicated voltage appears across the secondary of transformer which gives rectified output through diode D2. When Q is OFF inductor releases its energy through diode D1 and capacitor C. A resistor R is used across the capacitor C to limit the current when capacitor C discharges. The power is dissipated in this resistance in each cycle, when diode D1 is OFF. The regulated DC output is obtained at the output terminal of the circuit.