It could be isolated; it is not drawn as isolated.

Thank you. Can you please tell me whether you were able to get my simulation running on your computer? That may be an indication as to whether anyone else would be able to run it. LTSpice can be tricky...

> 20 years ago I did a DC isolated doubled SEPIC converter. Whereas a SEPIC would normally have common ground, I broke that and used bridging capacitance >100 nF instead. This was taking 12V input and making DC isolated 48V if I remember correctly. The application was generally for audio. The customer was very happy with the low noise of this converter. So, it indeed turns out that these variations are useful. Coming at it as a power supply designer, it is difficult to anticipate who will use what, and why.

 

I reloaded spice and got a newer version. It works now, I need a faster computer, but I am not making money now and may have to live with this one for a while.

 

I reloaded spice and got a newer version. It works now, I need a faster computer, but I am not making money now and may have to live with this one for a while.

Thank you. Understood. My old oscilloscope is like your computer....