December 2007, San Jose, California: It seems a long time ago.
I walked into a big networking company to head their small
Power over Ethernet (PoE) applications team. Surprisingly,
I hardly knew anything about PoE prior to that day, having been a
switching-power conversion engineer almost all my life. But it
seemed a great opportunity to widen my horizons. As you can see,
one notable outcome of that seemingly illogical career choice five
years ago is the book you hold in your hands today. I hope this small
body of work goes on to prove worthy of your expectations and also
of all the effort that went into it. Because, behind the scenes, there is a
rather interesting story to relate—about its backdrop, intertwined
with a small slice of modern PoE history, punctuated by a rather res-
tive search for our roots and our true heroes, one that takes us back
almost two centuries
