i think smd34063 or similar modern switchers can be managed within the space used by the models quoted by boncuk. perhaps collins concept need not increase the board space. basically let us realize the fixed voltage versions and they could be home-brew cheaper than cost of item suggested by boncuk.
@dirtylude,
if the component suggested by boncuk is checked, it would also have all these components and , it would also be called generic DC-DC converter, but bulk made by a company.
thus we should not bother to use 5 to 6 components, and home-brew one.
@collins55,
34063 cant work as DC Dc converter, without other components.
just one inductor cant make it up.
If you had made one, please publish, as it is not indicated in any datasheets and cant be logically apt.