>Maybe a $1.50 inductor will be part of the solution for
>my project, but in my country is not possible to get the
>adequate inductors as new parts.


I am sure that you could make a suitable one. In most cases the number of
microhenries needed is small enough to be only a few turns on a piece of
ferrite rod.

For your purpose I suspect that you could use a suitably uprated version of
the discrete transistor regulators that people like Russell or Roman Black
designed. Russell had one that took 150V input for a small (5-10V IIRC)
output voltage. Such a design should be reasonably happy with a wide-ish
(Russell again) range of inductor values.

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist