I have found a webinar I really want to view but the national semiconductor website has broken. I can't seem to find a mirror anywhere, any help is greatly appreciated:
http://sva.ti.com/en/videos/introduction_to_push_pull_cascaded_power_converter_topologies.html
http://sva.ti.com/en/videos/introduction_to_push_pull_cascaded_power_converter_topologies.html