I've attached recent photos of my AC rectifier setups here at "FB" office at my place.
One shows the 50 Volt rectifiers, filter caps on the main switchboard frame in the teleg office proper,
The other shows the 140 and 70 volt telegraph supplies on the power board in the garage.

These are basic simple transformer-rectifier-filter supplies. I used fullwave bridge rectifier module wired in a special way to obtain both positive and negative DC outputs.multiple 25 volt transformers with their primaries in parallel take 120VAC, from commercial.mains. The secondaries are wired in series to give 50 (two transformers) or 100 (four transformers) volts AC to the rectifiers. One side of the transformer secondary string goes directly to earth ground. The other side of the secondary string goes to the FWB rectifier module with the "AC" sides tied together. Then the positive and negative outputs of the rectifier module then go to the filter capacitors and bleeder resistors, with proper observation of polarity on the electrolytic caps. Outputs are run thru heat coils or Fuse distribution

This results in about 140 and 70 volts of both polarities from each supply at well over 1 Ampere for distribution. The lamp fields (40 Watt, 120 Volt lamps each)below the rectifiers and fuse boards serve as isolation and current limiting protection to various telegraph circuits