As we mentioned on other articles, 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 than that, usually removing the MOV, which is essential for cutting spikes coming from the power grid, and the first coil.

On this section this power supply is flawless, as it has more components than the necessary – one extra X capacitor, four extra Y capacitors and one extra coil. This power supply also features an X capacitor after the rectifying bridge.

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Figure 8: Transient filtering stage (part 1).

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Figure 9: Transient filtering stage (part 2).

A very interesting feature from this power supply is that its fuse is inside a fireproof rubber protection. So this protection will prevent the spark produced on the minute the fuse is blown from setting the power supply on fire. As you can see on Figures 6, 7 and 9 all coils used on this power supply are also protected by the same material.

In the next page we will have a more detailed discussion of the components used in the TX750W.