Enermax PRO82+ 525 W Power Supply Review

Primary Analysis

On this page we will take an in-depth look at the primary stage of Enermax PRO82+ 525 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU10J rectifying bridge in its primary, which support up to 10 A at 100° C. This bridge is attached to an individual heatsink and is clearly overspec’ed: at 115 V this unit would be able to pull up to 1,150 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 920 W without burning this component. Of course we are only talking about this component and the real limit will depend on all other components from the power supply.

Figure 9: Rectifying bridge.

The active PFC circuit uses two TK20J60T power MOSFET transistors, which one capable of handling up to 20 A in continuous mode or 40 A in pulse mode, both at 25° C. These transistors are located on the same heatsink as the switching transistors.

On the switching section this power supply uses another two TK20J60T power MOSFET transistors in the traditional two-transistor forward configuration.

Figure 10: Active PFC transistor (left) and switching transistor (right).

Figure 11: Switching transistor, active PFC diode, active PFC transistor and +5VSB switching transistor.

The primary section of this power supply is controlled by a CM6802B integrated circuit, which is a newer version of CM6800, the most popular active PFC/PWM controller combo around. On this new version the manufacturer guarantees at least 80% efficiency. Nice choice.

Figure 12: Active PFC/PWM controller combo.