Enermax PRO87+ 500 W Power Supply Review

Transient Filtering Stage

As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil. 

In this power supply, this stage is flawless. It has two Y capacitors and one coil more than the minimum required, plus one X capacitor after the rectifying bridge.

Figure 7: Transient filtering stage (part 1)

Figure 8: Transient filtering stage (part 2)

In the next page we will have a more detailed discussion about the components used in the Enermax PRO87+ 500 W.