As we mentioned on other articles and reviews, 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 and the first coil.

On this stage this power supply is flawless, providing two extra Y capacitors, one extra X capacitor and a ferrite bead attached to the main AC cable. This power supply also provides an X capacitor after the rectifying bridges.

click to enlarge
Figure 6: Transient filtering stage (part 1).

click to enlarge
Figure 7: Transient filtering stage (part 2).

Now let’s have a more detailed discussion on the components used on iPower 660.