**Subject :**Power Electronics

**Unit :**DC to DC Converters

## Two mode operation of chopper ( Buck Converter DC-DC)

**Analysis of Buck Converters (DC-DC):**

*Fig: Step-down chopper using thyristor Fig: Buck inductor waveform: inductor current waveform*

The mode of operation of chopper (Buck Converter DC-DC) can be classified mainly as Operation in (a) Discontinuous Load current and (b) Continuous Load current.

**Discontinuous Load current:**

*Fig: Buck converter in Discontinuous load current*

when the amount of energy required by the load is small enough to be transferred in a time lower than the whole commutation period. The current through the inductor falls to zero during part of the period. The inductor completely discharges at the end of the commutation cycle.

**Continuous Load current: **

*Fig: Buck converter in Continuous load current*

If the current through the inductor (I_{L}) never falls to zero during the commutation cycle the converter is said to be functioning with a continuous load current.