Understanding Series And Parallel Operation

The following will explain how multiple power supply channels can be connected in series or in parallel to increase their maximum output voltage or current.

Many DC benchtop power supplies have multiple channels and in most cases these channels are used independently to provide power to separate devices or loads. It is often also possible to combine the outputs of multiple power supply channels to increase the output voltage or current beyond that which can be provided by a single channel.

The only requirements for combining channels in this way is that the channels must be floating and galvanically isolated:

• Floating: the channels are not connected to the common instrument ground
• Isolated: the channels are independent of each other with no current flow between them

There are two ways power supply channels can be combined. If the channels are connected in series, this enables higher voltages. If the channels are connected in parallel, this enables higher currents. These connections are typically made externally, although in some cases these connections may be made within the supply itself.