What is Backup operation?
Use identical models for Power Supplies A and B.
Select the Power Supplies so that either one can supply the required load capacity.
When connecting Power Supplies for backup operation, always connect diodes (as shown in the diagram above) to prevent the failure in one Power Supply from affecting the Power Supply that is backing up operation. The following table shows the diode type, dielectric strength, and current characteristics.
Increase the setting of the output voltages of Power Supplies A and B by the forward voltage (VF) voltage drop of diode's D1 and D2. Also, the diodes will produce a power loss equal to Power Supplies' output current times the diodes forward voltage (IOUT × VF), so provide cooling so that the diode temperature remains below the specified catalog value.