This module came up last week.
To those of you trying to create something similar, has anyone looked at the
'reverse engineering' speculation at
http://www.geocities.com/soho/museum/4459/diy/sergewsh.html ? It has scope
traces of the module being put through its paces. It does look like a clever
series of biased full-wave rectifiers.
Again, that's from a printout, so I can't verify from here that it works
(I'm not actually at my PC at the moment...)