I think the confusion is that caps alone will provide a 'solution', as Andrew is saying, as that is what a capacitor is (a DC blocking device for cyclic signals). And the diodes provide protective functions for the capacitors.
The diodes only technique appears to me to also provide a solution, as the current peak that is associated with the transformer entering saturation is typically situated at the voltage zero-crossing part of the waveform (as that is where core flux is maximum for a sinusoidal voltage waveform, and superimposed is a DC current flux that pushes core in to saturation on one polarity of excursion) and so that current peak would be blocked to zero - apparently enough to alleviate the effect. Example waveforms in
http://www.diyaudio.com/forums/powe...id-transformers-what-right-4.html#post2105213
That said, I'd vote for the cap solution with protective diodes as the solution to apply.
The diodes only technique appears to me to also provide a solution, as the current peak that is associated with the transformer entering saturation is typically situated at the voltage zero-crossing part of the waveform (as that is where core flux is maximum for a sinusoidal voltage waveform, and superimposed is a DC current flux that pushes core in to saturation on one polarity of excursion) and so that current peak would be blocked to zero - apparently enough to alleviate the effect. Example waveforms in
http://www.diyaudio.com/forums/powe...id-transformers-what-right-4.html#post2105213
That said, I'd vote for the cap solution with protective diodes as the solution to apply.
An X2 66mF capacitor would not need diode protection.
That X2 would make an excellent DC blocker to prevent the "DC effect" of non symmetrical waveforms pushing a susceptible transformer towards saturation.
That X2 would make an excellent DC blocker to prevent the "DC effect" of non symmetrical waveforms pushing a susceptible transformer towards saturation.
"It was there for everyone to see. "
trobbins gets it:
"The diodes only technique appears to me to also provide a solution, as the current peak that is associated with the transformer entering saturation is typically situated at the voltage zero-crossing part of the waveform (as that is where core flux is maximum for a sinusoidal voltage waveform, and superimposed is a DC current flux that pushes core in to saturation on one polarity of excursion) and so that current peak would be blocked to zero - apparently enough to alleviate the effect. Example waveforms in
Variations of DC Main Filter against buzzing Toroid Transformers - what is the right?"
trobbins gets it:
"The diodes only technique appears to me to also provide a solution, as the current peak that is associated with the transformer entering saturation is typically situated at the voltage zero-crossing part of the waveform (as that is where core flux is maximum for a sinusoidal voltage waveform, and superimposed is a DC current flux that pushes core in to saturation on one polarity of excursion) and so that current peak would be blocked to zero - apparently enough to alleviate the effect. Example waveforms in
Variations of DC Main Filter against buzzing Toroid Transformers - what is the right?"
link is death. This URL goes open:
Mains DC and Transformers
check out post 178 under
https://www.diyaudio.com/forums/pow...zzing-toroid-transformers-18.html#post6442795
Mains DC and Transformers
check out post 178 under
https://www.diyaudio.com/forums/pow...zzing-toroid-transformers-18.html#post6442795
Last edited:
new Elliott link
Blocking Mains DC Offset From Transformers
© 2008, Rod Elliott (ESP)
Mains DC and Transformers
Blocking Mains DC Offset From Transformers
© 2008, Rod Elliott (ESP)
Mains DC and Transformers
Hi, I don't know if this was mentioned here before but looking around about various DC trap circuit I wondered why the pair of electrolytic caps sometimes are disposed in a antisymmetrical fashion sometimes in another. I mean is there a precise orientation (polarity) or that's indifferent for a proper working of the circuit? Most part of schematics report the capacitors are faced with the (+) each other but some in the opposite way. Until now I didn't find a useful explanation even though I suppose there's no preferable orientation due to the fact they're acting like like a unique bipolar capacitor.