> The second drawing has a single ground reference. Multiple grounds off > a single winding is my concern Yes, I see what you mean. I'm trying to consider the current flows when the AC reverses polarity ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2016.0.7998 / Virus Database: 4756/13888 - Release Date: 02/03/17 --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .