There are two technical indicators on the DC stabilized power supply: 

1.Index of characteristic, which reflect the intrinsic property of the DC stabilized power supply, such as input voltage, output voltage, current output, etc.

2.Index of quality, which reflect the good and bad of the DC stabilized power supply, such as the stability, equivalent internal resistance current cause to the change of the mains input.

Effect of the supply noise. For example, the supply noise has a important influence on the communication quality. Output end over-voltage influence. The short black out effect.