FSP300-60GHS Power Supply Review

Secondary Analysis

This power supply uses three Schottky rectifiers on its secondary, one for each main positive output (+12 V, +5 V and +3.3 V), and they are all from the same model: SBR30A50CT (30 A, 15 A per internal diode at 110° C, maximum voltage drop of 0.55 V).

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. Just as an exercise, we can assume a typical duty cycle of 30%.

This gives a maximum theoretical current of 21 A for each line. This translates into 257 W for the +12 V output, 107 W for the +5 V output and 71 W for the +3.3 V output.

All these numbers are theoretical. The real amount of current/power each output can deliver is limited by other components, especially by the coils used on each output.

Figure 13: Rectifiers.

The secondary is monitored by a PS229 integrated circuit. Unfortunately this device isn’t listed o its manufacturer website, so we can’t tell which protection it really supports.

Figure 14: Monitoring integrated circuit.

All electrolytic capacitors from the secondary are also from Teapo and labeled at 105° C, as usual.