NZXT HALE82 850 W Power Supply Review

Primary Analysis

On this page we will take an in-depth look at the primary stage of the NZXT HALE82 850 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses two GBU806 rectifying bridges, attached to an individual heatsink. Each bridge supports up to 8 A at 100° C, so in theory, you would be able to pull up to 1,840 W from a 115 V power grid. Assuming 80% efficiency, the bridges would allow this unit to deliver up to 1,472 W without burning themselves out. Of course, we are only talking about this particular compo
nent. The real limit will depend on all the components combined in this power supply.

Figure 10: Rectifying bridges

The active PFC circuit uses three FDP18N50 MOSFETs, each one supporting up to 18 A at 25° C or 10.8 A at 100° C in continuous mode (note the difference temperature makes), or 72 A at 25° C in pulse mode. These transistors present a 265 mΩ resistance when turned on, a characteristic called RDS(on). The lower the number is, the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.

Figure 11: The active PFC transistors

The output of the active PFC circuit is filtered by two 330 µF x 400 V Japanese electrolytic capacitors from Chemi-Con, labeled at 105° C. Since they are connected in parallel, they are equivalent to one 660 µF x 400 V capacitor.

In the switching section, two SPP24N60C3 MOSFETs are employed using the traditional two-transistor forward configuration. Each transistor supports up to 24.3 A at 25° C or 15.4 A at 100° C in continuous mode or 72.9 A at 25° C in pulse mode, with an RDS(on) of 160 mΩ.

Figure 12: One of the switching transistors and the active PFC diode

The primary is controlled by a CM6802 PWM/active PFC combo controller.

Figure 13: Active PFC/PWM controller

Let’s now take a look at the secondary of this power supply.