To show a schematic or sketch will require me to clean it up a bit..time. Any way what is E? EMF need I ?? Any way How do I get the EMF DC? Full bridge and a filter or two. No sweat at this time for worries about EMF varying with the load. My tests will all be in a steady state mode. I'll force them to be in that state for initial testing.
I am coming off a 15A circuit at the box to a std duplex receptacle, to a power strip w 10A resettable overload breaker I, then to a PS switch, then fused at 8A, then xformer, then to a rectifier and filter, then to another fuse (usually sized for the anticipated test load), then to a banana plug, then to my use building or trouble shooting things. Ok I want an Led just after each fuse to let me know when and if the device has exceeded my assessment (or name plate data) of I draw.at this time. I always have a handful of fuses. I tried to find a ckt breaker below 1 A but unless I pick a magnetic rather then thermal the price is way up there. Fuses and holders and led are much cheaper.
Later I may want to add better output regulation but my PS/Variack has worked well for over 15 years without it). I only wanted to add DM's and get rid of analog meters and the project got out of hand (bigger). Maybe thats since things have gotten more complex? I always break down the functions (of a device) in to steady state before proceeding with other tests. That usually finds the problem, 99% of the time if a smoke test does not for trouble shooting. In design if I blow a fuse (goofed, replace it try again). If it still blows a fuse increase the EI size until it works.
I'll sketch it up now but where and how do I include a drawing?