Akasa Essential Power 350 W Power Supply Review

Secondary Analysis

This power supply has three 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. Since on power supplies based on half-bridge topology the duty cycle is of 50%, we just need to add the total maximum current of all diodes connected to the specific line in question.

The +12 V output is produced by one F20C20C rectifier, which supports up to 20 A (10 A per internal diode at 125° C, 1.30 V maximum voltage drop, which is ridiculously high – meaning low efficiency), giving us a maximum theoretical current of 20 A or 240 W for the +12 V output. It is important to note that this rectifier isn’t from the Schottky type but from the Fast type, which presents lower efficiency.

The +5 V output is produced by one S20D45C Schottky rectifier, which supports up to 20 A (10 A per internal diode at 125° C, 0.65 V maximum voltage drop), giving us a maximum theoretical current of 20 A or 100 W for the +5 V output.

The +3.3 V output is produced by another S20D45C Schottky rectifier, giving us a maximum theoretical current of 20 A or 66 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 12: +3.3 V, +12 V and +5 V rectifiers.

The outputs are monitored by a discrete circuit based on an AZ339 integrated circuit (which has four voltage comparators inside) instead of using a ready-made monitoring integrated circuit.

Figure 13: Monitoring circuit.

The electrolytic capacitors from the secondary are from a company called BH.