nilton61:
Ecellent text, and really needed. What could be added is that power supplies should be unregulated with a filter/reservoir capacitor with a value of:
Thank you (and everyone else) for the kind words.
I have noted your very useful views about power supplies elsewhere but I don't feel competent to write a text about it myself. Perhaps you could find the time to write a few sentences which can either stand here as a separate post or I might incorporate it into my text.
My own experience is that a computer power supply (18v or so) and a large 12v lead-acid battery work fine. I haven't tried an unregulated supply myself to see if it would be better.
And I don't want to discourage or prevent newcomers from using a satisfactory power supply that they happen to have, even if it is sub-optimal.
...R