On 6/26/2013 1:24 PM, Paul Breed wrote:
In normal AC system DC bias is VERY rare. anytime a transformer is involved the dc bias goes to zero. Any AC powered device with a transformer in the front end of the power supply will likely fail in a catastrophic way if any significant DC bias is present. (You drive the transfomrer magnetic material into saturation and it stops being a transformer and becomes an air core inductor... with poor coupling
If fact, for DC the winding becomes just a wire, with a certain low resistance, and the DC voltage rapidly heats it to destruction. As noted.
Ol' Bab
