Series and parallel operation
Serial connection allows the connection of two or more power supplies serially to obtain a higher voltage rating. For serial connection, it is recommended that all power supplies operate under the constant voltage (CV) mode.
The images below show connections between two 3303D power supplies. One unit is set at 30V/2A and the other at 20V/3A. The image on the right shows the serial connection voltage/current output versus load changes.