I have made a normal linear power supply using bridge rectifier, capacitor....Its i/p 240vac 50hz & o/p 220Vdc & load it up to 6A.
I have seen the input current waveform at scope ,I think it is like harmonics current ?
And found that the input isolation transformer become very hot.
How to reduce or eliminate the input harmonics current produced by the non-linear diode ?

 

I have made a normal linear power supply using bridge rectifier, capacitor....Its i/p 240vac 50hz & o/p 220Vdc & load it up to 6A.
I have seen the input current waveform at scope ,I think it is like harmonics current ?
And found that the input isolation transformer become very hot.
How to reduce or eliminate the input harmonics current produced by the non-linear diode ?

maybe you put a big value capacitor for filtering and it draws much current from the supply due to the harmonics.

 

This is a problem solved by power factor correction (PFC). See the article:

http://en.wikipedia.org/wiki/Power_factor_correction

 

When 240VAC is rectified and filtered it produces 337VDC, not just 220VDC.
So I think 117V x 6A= 702W is lost in the isolation transformer.

 

http://www.silentpcreview.com/article28-page5.html

Well that's very interest and I thank your for the pointer Mr. Electrician.