Aerocool HorsePower 750 W Power Supply Review

Secondary Analysis

This power supply has four Schottky rectifiers on its secondary heatsink.

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%.

The +12 V output is produced by two STPS6045CW Schottky rectifiers connected in parallel, each one supporting up to 60 A (30 A per internal diode at 150° C, 0.84 V maximum voltage drop), giving us a maximum theoretical current of 86 A or 1,029 W for the +12 V output.

The +5 V output is produced by one STPS40L45CT Schottky rectifier, which supports up to 40 A (20 A per internal diode at 130° C, 0.70 V maximum voltage drop), giving us a maximum theoretical current of 57 A or 286 W for the +5 V output.

The +3.3 V output is produced by another STPS40L45CT Schottky rectifier, giving us a maximum theoretical current of 57 A or 189 W for the +3.3 V output.

It is always good to see the secondary highly overspec’ed like this.

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: +12 V, +5 V and +3.3 V rectifiers.

The outputs are monitored by two integrated circuits, a PS229 and a WT7518. There is no technical information available on the first one, and the second one is a four-channel over current protection circuit, possibly added to expand the over current protection from the PS229 into four channels.

Figure 14: Monitoring circuit.

The electrolytic capacitors from the secondary are from Samxon and labeled at 105° C as usual.