Primary Analysis

On this page, we will take an in-depth look at the primary stage of the Corsair GS700 Bronze. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses one GBU1506 rectifying bridge attached to an individual heatsink. This bridge supports up to 15 A at 100° C. So, in theory, you would be able to pull up to 1,725 W from a 115 V power grid. Assuming 80% efficiency, this bridge would allow this unit to deliver up to 1,380 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.

Corsair GS700Figure 11: Rectifying bridge

The active PFC circuit uses two SiHG20N50C MOSFETs, each supporting up to 20 A at 25° C or 11 A at 100° C in continuous mode (see the difference temperature makes) or 80 A at 25° C in pulse mode. These transistors present a maximum 270 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.

Corsair GS700Figure 12: Active PFC transistors

The output of the active PFC circuit is filtered by a 390 µF x 420 V Japanese electrolytic capacitor, from Chemi-Con, labeled at 105° C.

Corsair GS700Figure 13: Capacitor

In the switching section, two TK13A50D MOSFETs are employed using the traditional two-transistor forward configuration. Each transistor supports up to 13 A at 25° C in continuous mode or up to 52 A at 25° C in pulse mode, with a maximum RDS(on) of 400 mΩ. Unfortunately, the manufacturer doesn’t publish the current limits at 100° C.

Corsair GS700Figure 15: Active PFC/PWM controller

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

Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.