Sorry for being absent from this group for a couple of weeks. I have been at APEC for a week, then teaching our workshop in Atlanta.
Using Bridges for High Reliability Applications
We've had a lot of discussion about the LLC in another thread. I don't think it can go much further as I discovered at APEC. Many people contacted me privately about their experiences since much of what they know is confidential.
I hoped to get an answer to the real inside of phase shifted bridges and LLC converters, but it's not forthcoming yet. We have seen a posting that one online specification for power supplies explicitly bans the phase-shifted bridge, and other people have voiced their frustration about working with the LLC.
However, I have dug deeper, and found there is a more fundamental question that seems to be being asked in the industry - that is, should bridges even be used at all? There are failure events associated with the antiparallel diode of FETs, and questions about whether they can ever be reliable enough.
I welcome any comments on this.