Compare different soft-switching techniques and their applications.

Soft-switching minimizes switching losses by ensuring zero voltage or zero current at switching instant. ZVS (zero-voltage switching): voltage falls to zero before turn-on using resonant discharge or active clamp - suitable for MOSFETs whose turn-on loss dominates. ZCS (zero-current switching): current falls to zero before turn-off - better for IGBTs with tail current. Quasi-resonant converters achieve ZVS/ZCS through LC resonance but have variable frequency. Active clamp and resonant transition add elements to achieve soft switching at fixed frequency. Trade-offs include additional components, control complexity, and circulating current.