This power supply uses four 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 two MBR20H100CT Schottky rectifiers connected in parallel, which can deliver up to 20 A each (measured at 162º C), thus the maximum theoretical current the +12 V line can deliver is of 40 A, which equals to 480 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. The Green Star 450 W model we reviewed used different rectifiers, STPS20S100C, but they have the exact same specs from the rectifiers used on this power supply.

The +5 V output is produced by one STPS30S45CW Schottky rectifier, which support up to 30 A (measured at 135º C). So the maximum theoretical power the +5 V output can deliver is of 150 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. This is the exact same rectifier used on Green Star 450 W.

The +3.3 V output is produced by another STPS30S45CW Schottky rectifier, which support up to 30 A (measured at 140º C). So the maximum theoretical power the +3.3 V output can deliver is of 99 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. This is the exact same rectifier used on Green Star 450 W.

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 12: The four Schottky rectifiers used on the secondary.

This power supply thermal sensor is located close to one of the ends of the secondary heatsink, as you can see on Figure 13. This sensor is used to control the fan speed according to the power supply internal temperature and also to shut the power supply down if it implements over temperature protection (OTP), which isn’t the case of this power supply.

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Figure 13: Thermal sensor.

This power supply uses a SG6105 monitoring integrated circuit, which is in charge of the power supply protections. This IC features over voltage protection (OVP), under voltage protection (UVP), short-circuit protection (SCP) and over power protection (OPP). As you can see this IC doesn’t support over current protection (OCP) but Huntkey implemented this protection using a quad-comparator integrated circuit (AS339).

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Figure 14: Protection integrated circuits.

Analyzing the printed circuit board we could clearly see each +12 V rail connected to the OCP circuit. Also, each +12 V rail had its own filtering circuit (own coil and own electrolytic capacitor), which is nice to see.

The electrolytic capacitors used on the secondary are from Teapo and Fcon and rated at 105º C.

In summary, Dynex 400 W (Huntkey Green Star 400 W) is IDENTICAL to Huntkey Green Star 450 W.