Please see my recent upload, Autotransformer.zip

 

I need some tutorials regarding autotransformer modelling!

I was intrigued by Hassan's AC Stabilizer and tried to model TR1

The model differed from my expectations in several ways.

1: Why do the tap-to-tap voltages differ, with equal inductances?

2: Why is the separate 18V winding so different?

2a: Why is it more different when I separate the Kxxx directives?

3: Why do the outputs throw infinities with small or megohm loads, but not when 1G or open??

It's not quite the same as your schematic, but I uploaded an autotransformer model earlier this year. If you searched the Files section for examples of "Autotransformer" you wouldn't have found it, because I called it a "Variac", which was actually an old trademarked name, but I guess it stuck.

Briefly, I investigated Helmut Sennewald's previous model and found where that was going wrong, and fixed it. (I continue to be amazed how much work Helmut put into this group.)

You might find the workings of the model useful in modelling autotranformers with more taps, or just in general. It was deceptively difficult to accurately model a variac properly, which is presumably why I didn't find any other working models out there.

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