This application discloses a converter and a power adapter, to reduce an energy loss of the power adapter. The converter includes: a DC power supply, a primary power transistor, an auxiliary power transistor, a first capacitor, a transformer, and a control...

A power supply apparatus is provided with a power supply transformer; excitation circuit portions provided at a primary side of the power supply transformer, for exciting the power supply transformer by means of a commercial power supply; and control circu...