try: power.ti.com/seminars and click "On-line Training and Tech Webcasts".
audio webcasts on:

DC/DC Converter with Current Doubler Synchronous Rectification Achieves 92%
Efficiency (by Laszlo Balogh)

Practical Considerations in Troubleshooting and Optimizing Power Supply
Control Circuits and PCB (by Bob Mammano, Bill Andreycak and Jim Noon)

Magnetics Design (by Lloyd Dixon)

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