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.

Even though this power supply has one X capacitor and two Y capacitors more than the minimum required plus one extra coil and one extra X capacitor after the rectification bridge, it doesn’t come with a MOV, which is the component in charge of removing spikes coming from the power grid. This stage from the 400 W model is superior, as it features a MOV.

OCZ StealthXStream 500 W Power SupplyFigure 7: Transient filtering stage (part 1).

OCZ StealthXStream 500 W Power SupplyFigure 8: Transient filtering stage (part 2).

In the next page we will have a more detailed discussion about the components used in the OCZ StealthXStream 500 W.

Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.