Corsair GS500 Power Supply Review

Secondary Analysis

The Corsair GS500 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 four Schottky rectifiers, two SBR30A60CT (30 A, 15 A per internal diode at 110° C, 0.60 V maximum voltage drop) for the direct rectification and two SBR40U60CT (40 A, 20 A per internal diode at 25° C, 0.60 V maximum voltage drop) for the “freewheeling” part of the rectification. This gives us a maximum theoretical current of 43 A or 514 W for the +12 V output. 

The +5 V output uses two STPS3045CT Schottky rectifiers (30 A, 15 A per internal diode at 155° C, 0.84 V maximum voltage drop). This gives us a maximum theoretical current of 43 A or 214 W for the +5 V output.

The +3.3 V output uses one STPS4045CW Schottky rectifier (40 A, 20 A per internal diode at 140° C, 0.94 V maximum voltage drop). This gives us a maximum theoretical current of 29 A or 94 W for the +3.3 V output.

Figure 14: The +12 V, +5 V, and +3.3 V rectifiers

This power supply uses an ST9S429 monitoring integrated circuit, which apparently is a rebranded S3515. This chip supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. Even though this chip provides two +12 V over current channels, the manufacturer decided to configure this unit as a single-channel model.

Figure 15: Monitoring circuit

The electrolytic capacitors that filter the outputs are from Teapo and Samxon and labeled at 105° C, as usual.