On Tuesday, December 12, 2017 at 3:38:21 AM UTC-5, GS wrote:


In my experience 10% droop is pretty good. 15% more common. I'm just
talking transformers in general. A Feroresonant one will do good.

Sola-type CV transformers put out a wretched wave-form. If your connected device is sensitive to mains noise, they will not work out so well. They will also back-feed noise in some cases.

It is important to understand that a purpose-made isolation transformer is designed not to sag, and is not-ever-never-ever operated at the margins of its theoretical design. They are operated at a limit well below their theoretical capacity for just this reason. Back-to-back kluges are the product of desperation or a McGyver type with a small brain, emphatically not any sort of long-term or permanent application.

Peter Wieck
Melrose Park, PA