High Squareness Ratio of a Transformer

[NV&H]

I have noticed that "high squareness" Cobalt Amorphous cores seem to have very high permeabilities and very low coercivities. Because of this, a high magnetic flux remains in the core after having been saturated and then followed by current being removed from the primary coil. High Br.

That doesn't sound very good for an audio transformer but because the coercivity is so low, very little reverse magnetic flux (induced by changing polarity of the coil voltage) is needed to reverse the flux in the core. Low Hc. That, on the other hand, sounds very good for an audio transformer.

So, my questions is this: Does the very low Hc sufficiently counter the negative effects of the high Br in such cores to make for a good transformer?

[jlsem]

That's a good question. Cobalt amorphous cores with very square B-H loops tend to be very non-linear (like most square-loop alloys) and really aren't suitable for audio, not to mention the high cost. I thought about playing around with Deltamax for push-pull transformers, but I ended up feeling that the fast switching properties couldn't outweigh the non-linearities.

John