Output voltage programming function in powerful RSP series power supplies from MEAN WELL

The developed functionality of power supplies is always one of the reasons why a decision is made in favor of one series or vice versa - replacing it with a simpler one. But, as a rule, the wider the set of available functions, the better. In the vast majority of switching power supplies from MEAN WELL, there is a slight adjustment of the output parameters, mainly the output voltage, which allows you to compensate, for example, for a voltage drop on the load connection wires or to obtain some non-standard value. However, the range of such adjustment is small - about ± 5 ... 10% of the nominal value, which greatly limits the possibility of using these power supplies in some non-standard cases.

Therefore, in order to expand the boundaries of possible applications, as well as provide the possibility of using switching power supplies in specialized or laboratory equipment, in powerful power supplies (from 750W and above), MEAN WELL implements the output voltage programming function (Output Voltage Programming or PV / remote voltage programming /remote adjust/margin programming/dynamic voltage trim). The limits of changing the output voltage level in the presence of this function are significantly expanded, and not only down, but also up - from 20-40% to 110-120% of the nominal value of the output voltage, depending on the family and series of MEAN WELL switching power supplies . So for power supplies of the RSP-750 series, the limits for changing the output voltage are possible from 40 to 110% when the voltage changes from 2 to 5.5V of an external DC voltage source:

Graph of output voltage change in RSP-750 series power supplies

For all additional functionality, a special connector with output contacts is installed in the power source to implement the function, and the Specification provides connection diagrams and / or connection of additional elements for its control and comments on use. On the example of power supplies of the RSP-750 series, the location of the additional connector and the connection diagram of the output voltage programming function by connecting an external voltage source (the circuit is highlighted in green):

Additional connector in RSP-750 series power supplies

Connection diagram of the output voltage programming function using the RSP-750 as an example

By default, when leaving the factory, the output voltage programming function is not activated, and the PV (pin5) and PS (pin6) pins are shorted with a jumper. If this function is not required, then the PV (pin5) and PS (pin6) pins should also be kept shorted, otherwise the power supply will not have an output. Note: similarly, the deactivation of other additional functions in the power supplies of the RSP-750 series is shown in a different color (the installation of jumpers in these places is implied).

However, the way to program the output voltage is possible not only by adjusting the voltage from an external DC voltage source within the required range of values. The second possible way is to program the output voltage using an external variable resistance. So, this method is implemented in the popular RSP-1000 series power supplies. To reduce the output voltage level, the external resistance R1 is connected in one way:

Optional connector and voltage reduction connection RSP-1000

Wiring diagram of the output voltage programming function to reduce

To increase the output voltage level, the external resistance R2 is connected differently:

Additional connector and connection to increase the voltage RSP-1000

Wiring diagram of the output voltage programming function to increase

The limits for changing the output voltage using external resistances R1 and R2, as well as the ratings of their maximum resistance values for power supplies of the RSP-1000 series are shown in the figure:

Limits of output voltage change with the help of external resistances RSP-1000

At the same time, there is also a way to program the output voltage using an external DC voltage source (the connection diagram and adjustment limits can be specified in the Specification). You can also clarify the availability of the output voltage programming function and how it is implemented in the Specification for any other selected series of powerful box-type power supplies (from 750W and above).

For questions related to the selection and use of MEAN WELL products, please contact Meanwell@chipdip.ru .