# DC-DC power modules

The APU board we are using supports a fixed voltage of 12V. Since we have to deal with cable losses, we have to make sure to convert the incoming voltage to a stable 12V source. This is done using DC-DC power modules.

DC-DC power modules comes in many schapes and sizes. Erricsson provides a nice [Test Guide] to verify the DC-DC power modules in many different ways.


[Test Guide]: <http://archive.ericsson.net/service/internet/picov/get?DocNo=28701-EN/LZT146243&Lang=EN&HighestFree=Y>