>By the way, Joerg suggested we add an overvoltage protection >circuit, e.g., conceptually like this crowbar (in German, sorry): > >http://www.elektronik-kompendium.de/public/schaerer/crowbar.htm > >The overvoltage protection would have to be synchronized such >that an excursion - e.g., when 3V3 and 5V are shorted - on >3V3 would also shut down 5V. > >While I don't think anybody would be too eager to implement such >a thing for M1r4, I think it's something we should keep in mind >when the time for a more comprehensive redesign of the M1 power >circuit comes. > >If taken into account at design time and when selecting >components, we can probably find a solution that has this sort >of overvoltage protection with no or only a small number of extra >components. > >- Werner
The rationale for this been (Werner's) worries about accidentally creating a path from +5V to +3V3 by some shortcircuit e.g. by misplacing J21 plug. For a ruggedized experimental board such a crowbar OVP would cause 3V3 OVP to trip in this case (via clamp diodes, for GPIO) which ideally shuts down both 3V3 and 5V in no time before any component suffers permanent damage. /j _______________________________________________ http://lists.milkymist.org/listinfo.cgi/devel-milkymist.org IRC: #milkymist@Freenode
