Thanks for sharing, Colin! I had been wanting to initiate a thread to get a HiQ feeling for how the Voltage range of inductors in general, be it electromotors or transformers, should be considered possible and efficient. Naturally the low Voltage limit is not much of a mental problem for me to imagine, or kind of visualize the formulas to estimate, either in static (electromagnet) or dynamic sense (max frequency of field change). So if the voltage gets larger and the pulses get thinner, I guess factors like switching frequency and gate charge, may become sources for inefficiency that will establish limits to what makes sense... I do recall sites like 400 Hertz net where people where advocating for smaller AC induction motors with higher RPM to save weight and still have powerful tools and vehicles. But I also am wondering about the direct drive type of motors (for example a permanent magnet bicycle hub motor) that can do gearless efficiency energy recovery (ok not that much Voltage and efficiency :), what would be the implications of thin pulses of lets say 10times specification of system Voltage during a smooth start-up? Sorry for hijacking the thread! Any interesting thoughts or references highly appreciated! On 8/28/14, CDB wrote: > Just happened upon this web page that contains the old Unitrode training > manuals containing tutorials on SMPS design. > > PDf's from 1983 - 2001. > > http://www.smps.us/Unitrode.html > > Colin > > -- > cdb, 28/08/2014 > > -- > > > > > colin@btech-online.co.uk > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=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 .