Seasonic S12II Bronze 430 W Power Supply Review

Secondary Analysis

The Seasonic S12II Bronze 430 W uses a regular design in its secondary, with Schottky rectifiers.

The maximum theoretical current each line can deliver is given by the formula I / (1 – D) where D is the duty cycle used and I is the maximum current supported by the rectifying diode. As an exercise, we can assume a duty cycle of 30 percent.

The +12 V output uses two SBR30A50CT Schottky rectifiers (30 A, 15 A per internal diode at 110° C, 0.55 V maximum voltage drop), giving us a maximum theoretical current of 43 A or 514 W for the +12 V output.

The +5 V output uses one MBR30H30CTG Schottky rectifier (30 A, 15 A per internal diode at 138° C, 0.55 V maximum voltage drop). This gives us a maximum theoretical current of 21 A or 107 W for the +5 V output.

The +3.3 V output uses another MBR30H30CTG Schottky rectifier. This gives us a maximum theoretical current of 21 A or 71 W for the +3.3 V output.

Figure 13: The +12 V, +5 V, and +3.3 V rectifiers

This power supply uses an HY510N monitoring integrated circuit, which only supports over voltage (OVP) and under voltage (UVP) protections.

Figure 14: Monitoring circuit

The electrolytic capacitors that filter the outputs are also Japanese, from Chemi-Con, and labeled at 105° C, as usual.