This is what I was going to suggest. 48vdc distribution, small 48vdc to whatever voltage buck converter at each location. If you use a switchmode buck converter, the 48vdc current will be much lower. The converters will automatically adjust for the varying voltage created by the varying load. You could also do 24v if the current isn't that high. Depending on the robustness vs cost trade-off you can either get something really cheap and likely to be reliable or spend a bit more and get something from a known brand. I personally have had good luck with meanwell converters. On Oct 13, 2017 7:22 PM, "Jason White" wrote: > It may be easier to buy small 5v regulator modules and place them at each > load. Readily available on ebay or as evaluation boards on digikey. > > On Fri, Oct 13, 2017 at 8:26 PM, Justin Richards < > justin.richards@gmail.com> > wrote: > > > On 13 October 2017 at 23:09, Bob Ammerman wrote= : > > > > > Why not run a higher voltage around (12V?) and regulate (switcher?) a= t > > each > > > location. This will result in less IR loss because the current will b= e > > > less, > > > and the regulators will hide a lot of garbage on the supply from the > > load. > > > > > > ~ Bob Ammerman > > > RAm Systems > > > > > > This is do-able. I have a bunch of switching regulators. > > > > My initial concern was less to do with volt drop but more with spikes, > > inrush currents and ways to be generally nice to the PSU and the device= s > > connected along the run.. > > > > The UNO has a 5v regulator which I thought would be perfect but sadly r= an > > too hot running from 12v in. Spec is 7-12v. > > > > Slightly related, EEVBLOG and TheSignalPath have recently discussed > > switching PSU's and related noise but I am interested in a discussion > about > > how much noise the mainstream digital devices such as ESP's and Arduino= 's > > can tolerate. > > > > The general wisdom seems to be, keep noise to a minimum but that is a b= it > > vague. > > > > I understand if sensitive analog measurements are required then noise i= s > > paramount but for general processor operation what is an acceptable noi= se > > level or W/Hz. > > > > I have repaired a bunch of old arcade PCB's from the 80's and on severa= l > > occasions during repair I examined the power rails at various points. > The > > hash on these rails is huge and often assumed that was the cause of the > > failure but was never the case. I was regularly amazed that these PCBs > > continued to run flawlessly considering what I saw on the scope. > > > > Justin > > -- > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > > > > > -- > Jason White > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .