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, two extra Y capacitors, one extra coil and a ferrite bead on the main power cable. This power supply also features an X capacitor after the rectifying bridge.

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Figure 7: Transient filtering stage (part 1).

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Figure 8: 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.

In the next page we will have a more detailed discussion of the components used in the Silencer 610 EPS12V.