28VDC Power Supply
     Two power supplies feed the same DC line but are diode islolated. This keeps the power supples from "talking to each other" and prevents damaged to pass transistors, over current sensors etc.
   
 




       Some of my favorite power supplies use constant voltage transformers. Most of mine are made by Sola These type of power supplies are all most bullet proof.
 



      Sola Constant Voltage Supply.