On Sun, 26 Apr 2009 19:39:23 +1000, Sylvia Else wrote:

http://www.onsemi.com/pub_link/Collateral/NCP1653-D.PDF
Sylvia.

Most interesting! I'd been wondering how it's done. Basic circuit is
quite simple. Although I didn't read carefully, it seems that only at the
end did I learn that it can provide 300 VDC to the inverter; wasn't sure
until then whether the complete circuit was for low voltage output.

I'd guess that total component cost is pretty modest.

Regards,
nb