This power supply uses three Schottky rectifiers on its secondary. The problem is how they are connected. Instead of using the same design adopted by all current power supplies, the reviewed power supply uses an old design. To see the difference between them, take a look on the Secondary section from our Anatomy of Switching Power Supplies tutorial. This power supply secondary uses the design described as “A” on this tutorial, while almost all power supplies currently on the market uses the design described as “B”.

The +12 V output is produced by one S30D60C Schottky rectifier, which can deliver up to 30 A (measured at 25º C), which equals to 360 W. The maximum current this line can really deliver will depend on other components, especially the transformer, the coil, the capacitor and the wire gauge used. It is also important to notice that almost all power supplies nowadays use two rectifiers connected in parallel on the +12 V line instead of just one.

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Figure 10: +12 V rectifier.

The +5 V output is produced by one S60D40C Schottky rectifier, which support up to 60 A (measured at 25º C). So the maximum theoretical power the +5 V output can deliver is of 300 W. Of course the maximum current (and thus power) this line can really deliver will depend on other components, especially the transformer, the coil, the capacitor and the wire gauge used, as mentioned before.

The +3.3 V output is produced by another S60D40C Schottky rectifier, which support up to 60 A (measured at 25º C). So the maximum theoretical power the +3.3 V output can deliver is of 198 W. Of course the maximum current (and thus power) this line can really deliver will depend on other components, especially the transformer, the coil, the capacitor and the wire gauge used, as mentioned before.

Even though this power supply has a separated rectifier for the +3.3 V output, this rectifier is connected to the same transformer output as the +5 V line, so the maximum current +5 V and +3.3 V can pull together is limited by the transformer.

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Figure 11: +3.3 V and +5 V rectifiers.

Here it is crystal clear to us that this power supply uses an obsolete design adapted to meet current market demands – in order words adding SATA power connectors on an old power supply doesn’t mean that the power supply is new! We say that because the +5 V and +3.3 V rectifiers are capable of delivering far more current (and thus power) than the +12 V rectifier. This was the typical scenario with power supplies from SEVEN years ago. Nowadays most power is pulled from the +12 V as the components that pull most of the power – CPU’s and video cards – are connected to the +12 V line.

This power supply thermal sensor is located inside the +12 V coil, as you can see on Figure 12. This sensor is used to control the fan speed according to the power supply internal temperature and also to shut it down in the case of an overheating situation on power supplies that implement over temperature protection (OTP).

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Figure 12: Thermal sensor.

On this power supply the big electrolytic capacitors from the voltage doubler are rated at 85º C, while the electrolytic capacitors from the secondary are rated at 105º C. We couldn’t find out their brands.