On 3/13/2017 12:28 PM, Joerg wrote:

snip

You could stick in a Murata LXDC55FAAA-203
http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf
instead of the zener and do a USB version also with only three parts.
But I know that you love designing your own switchers.


$3.50? Mon Dieu! :-)

I got some of the Murata LXDC55FAAA-203 units from Digikey for use at
work. I guess I didn't realize from the picture on the data sheet just
how tiny these things are. Maybe I'll buy some more and try building
some dynamo to USB adapters.