power dissipation

Hi
Does any one has article on
" calculating the power dissipation of the regulator in a DC power supply"
Or any relevant info would be much appreciated.
Thankyou

Sure. For a linear voltage regulator you multiply the load current by the voltage drop across the regulator and that is how much heat the regulator needs to dissipate.

For a switcher it gets a bit more complicated, but if you can measure or compute the output power and you know or can measure the input power then the difference will be dissipated in the switch and the magnetics.