More 11/750 PSU Qs

Lee, the point is: And this requires the over-current protection to not shut down the individual supply, but instead have it contribute as much as can safely be done. On the other hand... This will be inhibited by the above-mentioned load-sharing feature, so you need some kind of "communication" between the supplies in order to be able either to share load or to completely shut down all others instead of running them in current-limiting mode after some have failed. This would even take us further, into redundancy. Nice idea! The only thing that needs preparation for this may be mechanics: you wouldn't want to try unscrewing thick power wires and risking them to touch any other metal parts inside a running system... My remark... ... was referring to the effect of individual supplies going back and forth between current-limiting and voltage-limiting mode, which can indeed make them perform very poorly. I take this for agreed. With a constant load, you could avoid this problem by properly designing the system. Yes, if minimum loading would be required, things would get worse. In this case, you would need a way of shutting down one or more of the bunch completely in order to comply with the minimum loading requirement for the others. We get to a point where a microcontroller makes sense to control this, and I have seen this in real systems. So, I think the bottom line is: running PSUs in parallel is something that really can be done, but there are several bells and whistles you need to take into account. -- Andreas Freiherr Vishay Semiconductor GmbH, Heilbronn, Germany http://www.vishay.com