Secondary Analysis
Contents
On this page we will take an in-depth look at the primary stage of the Antec High Current Gamer 520 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.
This power supply uses one GBU806 rectifying bridge, attached to an individual heatsink. This bridge supports up to 8 A at 100° C, so in theory, you would be able to pull up to 920 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 736 W without burning itself out. Of course, we are only talking about these particular components. The real limit will depend on all the components combined in this power supply.
Figure 10: Rectifying bridge
The active PFC circuit uses two FDP18N50 MOSFETs, each supporting up to 18 A at 25° C or 10.8 A at 100&d
eg; 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 the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.
Figure 11: One of the switching transistors, active PFC diode, and active PFC transistors
The output of the active PFC circuit is filtered by a Japanese capacitor, from Chemi-Con, labeled at 85° C.
In the switching section, another two FDP18N50 MOSFETs are used in the traditional two-transistor forward configuration. The specifications for these transistors were discussed above.
Figure 12: The other switching transistor
The primary is controlled by an ICE1CS02 active PFC/PWM combo controller.
Figure 13: Active PFC/PWM combo controller
Let’s now take a look at the secondary of this power supply.
