Can the voltage of outdoor power supply be adjusted

Power supplies are usually set to a fixed output voltage to supply an electrical load with energy. Certain applications, however, require a variable generated voltage. This article will show how output voltages of a power supply may be adapted on-the-fly using dedicated digital-to-analog converters (DACs) developed for such purposes.

The output voltage of a power supply is usually a fixed voltage, but sometimes it may be necessary to adjust that output voltage. For example, you may be able to reduce the power dissipation in a low-voltage high-current processor – while still keeping performance high – by adjusting the voltage fed to the core.

AC-DC power supplies and DC-DC converters often feature an output voltage adjustment, the range of which is stated in the datasheet. An AC-DC power supply may have a potentiometer accessible to set the output voltage from the original factory set point. (See Figure 1).

Using AVS allows the processor to optimize the core voltage, thus improving performance and reducing power dissipation. This is just one example of how to create an adjustable-output power supply. For more information, see my latest Power Tips post on EETimes.

An AC-DC power supply may have a potentiometer accessible to set the output voltage from the original factory set point. Board mount DC-DC converters may also have an output voltage adjustment range, usually achieved via the “trim” terminal. The trim connection is either pulled high or low via a resistor depending on the product.

Any noise or voltage drop at the DAC output will cause unexpected output voltage variation. It should also be noted that when adjusting the output up in voltage, the maximum power rating of the power supply or converter is not exceeded. Likewise the maximum current must not be exceeded when the voltage is below the nominal set point.