> not enough inductance I'd put that off till last as winding inductors is not one of my favourite things. I'll have to dig out enough thick wire for a large inductor, not even sure if the biggest toroid I've got is big enough to make a 1mH 5A Looking around Google for what a 1mH might look like I see these, I've got several from dead PC PSUs https://www.alibaba.com/product-detail/iron-core-coils-1mh-inductor_1938724= 065.html Are they suitable ? Joe=20 ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2016.0.7998 / Virus Database: 4749/13861 - Release Date: 01/29/17 --=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 .