Xigmatek Tauro 700 W Power Supply Review

Primary Analysis

On this page we will take an in-depth look at the primary stage of the Xigmatek Tauro 700 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses one BU1506 rectifying bridge, which is attached to an individual heatsink. This bridge supports up to 15 A at 80° C. So, in theory, you would be able to pull up to 1,725 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,380 W without burning itself out. Of course, we are only talking about this particular component. The real limit will depend on all the components combined in this power supply.

Figure 10: Rectifying bridge

The active PFC circuit uses two SPW24N60C3 MOSFETs, each supporting up to 24.3 A at 25° C or 15.4 A at 100° C in continuous mode (see the di
fference temperature makes) or 72.9 A at 25° C in pulse mode. These transistors present a maximum 160 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.

The output of the active PFC circuit is filtered by one 390 µF x 420 V electrolytic capacitor from Teapo, labeled at 85° C.

In the switching section, another two SPW24N60C3 MOSFETs are employed using the traditional two-transistor forward configuration. The specifications for these transistors were already discussed above.

Figure 11: The switching and active PFC transistors

The primary is managed by the famous CM6806 active PFC/PWM combo controller. 

Figure 12: Active PFC/PWM combo controller

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