Apparatus and method for providing multiple functions and protections for a power converter

A method for providing multiple functions or protections for a power converter including a transformer having a primary winding connected between a power input and a power switch, and a secondary winding connected to a power output, and operative to deliver power from the power input to the power output by switching the power switch by a control signal, the method comprising the steps of:

• generating an induced voltage by an auxiliary winding inductively coupling to the primary or secondary winding in such a manner that when the power switch is at a first switch state, the induced voltage reflects an input information of the power converter, and when the power switch is at a second switch state, the induced voltage reflects an output information of the power converter;
• generating a first detection signal from the input information;
• and
• generating a second detection signal from the output information;
• whereby the first and second detection signals are used to implement the multiple functions or protections.