Huntkey LW-3550HG has four Schottky rectifiers on its secondary, two for the +12 V output, one for the +5 V output and one for the +3.3 V output.

Since this power supply uses a half-bridge configuration to calculate the maximum theoretical current each output can deliver is easy: all we need to do is to add the maximum current supported by all diodes.

The +12 V output is produced by two BYQ30E200 Schottky rectifiers connected in parallel, each one capable of handling up to 16 A at 104º C (8 A per internal diode). So the maximum theoretical current the +12 V output from this power supply can deliver is of 32 A or 384 W. Of course this math is just an exercise and the actual limit depends on several other factors. These rectifiers have a lower current limit compared to the ones used on the 400 W and 450 W Green Star models.

The +5 V output is produced by one S30D40C Schottky rectifier, which is capable of handling up to 30 A at 80º C (15 A per internal diode). So the maximum theoretical current the +5 V output from this power supply can deliver is of 30 A at 80º C or 150 W. This is the same component used on the 400 W and 450 W models.

The +3.3 V output is produced by one STPS3045CT Schottky rectifiers, which is capable of delivering up to 30 A at 155º C (15 A per internal diode). So the maximum theoretical current the +3.3 V output from this power supply can deliver is of 30 A at 155º C or 99 W. The 400 W and 450 W models use a different component with a higher dissipation area (TO-247 packaging instead of TO-220 as used on this power supply) but with the same current limits.

It is always good to remember that the real current/power limit for each output will depend on other factors, like the coils and the width of the printed circuit board traces.

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Figure 10: +5 V rectifier and +12 V rectifier.

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Figure 11: +12 V rectifier and +3.3 V rectifier.

In Figure 12, you can see the thermal sensor available below the secondary heatsink, in charge of changing the fan speed according to the power supply internal temperature.

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Figure 12: Thermal sensor.

Instead of using a monitoring integrated circuit, the protections from this power supply are implemented discretely, using two LM339 voltage comparators. In Figure 13 you can also see the AZ7500B PWM controller, which is in charge of controlling the switching transistors.

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Figure 13: Monitoring circuit.

The electrolytic capacitors from the secondary are from Teapo and Fcon and labeled at 105º C, as usual.