Cascading the Outputs of the PXI-4110 to Extend Voltage and Current Ranges
Updated Feb 4, 2020
This tutorial is part of the National Instruments Measurement Fundamentals series. Each tutorial in this series, will teach you a specific topic of common measurement applications, by explaining the theory and giving practical examples. This tutorial describes how increase the voltage and current output by cascading the outputs of a multi-channel power supply or supplies.
Cascading Power Supply Channels to Increase Voltage Output
Sometimes an application requires more voltage than a single channel of a programmable power supply can output. If your power supply offers isolated outputs or a combination of isolated and non-isolated channels, you can easily extend the maximum output range by cascading channels in series.
For example, the NI PXI-4110 triple output power supply offers default configuration shown in figure 1.
Figure 1. (A) The PXI-4110 Default configuration and (B) Cascading two channels to create a single +40V@1A channel
NOTE: When cascading modules, be sure to not exceed the maximum common mode of a power supply. For example, the PXI-4110 has a maximum common-mode of +60VDC from ground
Cascading Power Supply Channels to Increase Current Output
If your power supply offers isolated outputs or a combination of isolated and non-isolated channels, you can easily extend the maximum output range by cascading channels in parallel. This type of configuration is sometimes quicker or even costs less than purchasing a new higher-current power supply.
For example, you can extend the current output of a single NI PXI-4110 power supply by cascading an isolated and non-isolated channel, as shown in figure 2.
Figure 2. (A)Cascading two channels to create a single +6V@2A channel (B) Cascading the +20V channel from two PXI-4110 modules to create a single +20V@2A channel