As we mentioned on other articles, the first place we like to take a look when opening a power supply to have a hint about its quality is its filtering stage. The recommend 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 – two extra X capacitors, two extra Y capacitors and one extra coil.

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Figure 8: Transient filtering stage.

On almost all power supplies we’ve seen lately some components from the filtering stage are attached to the power cord connector, which isn’t the case of this power supply.

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.

Now let’s have a more detailed discussion on the components used on BFG 800 W.