Yes, true enough.
I suspect that the conventional current flow model of circuits, i.e; from +ve to -ve arose because it looked more sensible and was easier to follow. Circuits are usually drawn with the +ve voltage rail at the top and the -ve rail (which is often earth or chassis earth too), at the bottom. This makes 'reading' an electronic circuit much more intuitive - like a page of a book - one imagines the current flowing from top to bottom, and (usually) left to right, rather than what it actually does; from bottom to top. It makes no real difference to one's understanding of a circuit whether one is thinking of positrons (or 'holes') flowing from +ve to -ve, or electrons flowing in the opposite direction.
I suppose you could ask why we write words from left to right, and from top to bottom - it could be done differently, for example Chinese and some Middle Eastern languages, but it's just a convention I guess.
Now, can someone remind me why positive earth vehicles arose? It was to do with electrolytic corrosion I think - does anyone know?
U
Last edited by Uplinker; 7th March 2013 at 08:28.