Corsair CX430 Power Supply Review

Primary Analysis

On this page we will take an in-depth look at the primary stage of the Corsair CX430. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU806 rectifying bridge on its primary, which, unfortunately, isn’t attached to a heatsink. This component supports up to 8 A at 100° C (if a heatsink is used; the manufacturer doesn’t say how much current this bridge supports when not attached to a heatsink), 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 this component, and the real limit will depend on all the other components in this power supply.

Figure 10: Rectifying bridge

The active PFC circuit uses two STP14NK50ZFP MOSFET transistors, each one supporting up to 14 A at 25° C or up to 7.6 A at 100° C (not
e the difference temperature makes) in continuous mode, or up to 48 A in pulse mode at 25° C. This transistor presents a 380 mΩ resistance when turned on, a characteristic called RDS(on). The lower this number the better, meaning that the transistor will waste less power and the power supply will have a higher efficiency.

Figure 11: Active PFC transistors and diode

The electrolytic capacitor that filters the output of the active PFC circuit is from Samxon and labeled at 85° C.

In the switching section, two AOTF10N60 power MOSFETs are used in the traditional two-transistor forward configuration. Each one supports up to 10 A at 25° C or up to 7.2 A at 100° C in continuous mode, or up to 36 A at 25° C in pulse mode, with an RDS(on) of 750 mΩ, which is very high.

Figure 12: Switching transistors

The primary is controlled by the omnipresent CM6800 active PFC/PWM combo.

Figure 13: Active PFC/PWM combo controller

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