==== ZVS ===== http://www.intersil.com/data/an/an1246.pdf http://www.deltartp.com/dpel/dpeltechjournals/Soft-Switched%20PFC_YJ.%20and%20MM%20Jovanovic.pdf http://www.molla.org/DIY-CDI/SC-DIY-CDI-article-hires.pdf