Cooler Master Elite Power 400 W Power Supply Review

Primary Analysis

On this page we will take an in-depth look at the primary stage of Cooler Master Elite Power 400 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU806 rectifying bridge, which supports up to 8 A at 100° C if a heatsink is used, which is not the case, or up to 3.5 A at 100° C if a heatsink isn’t used. At 115 V this unit would be able to pull up to 403 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 322 W without burning itself out. Of course we are only talking about this component and the real limit will depend on all other components from the power supply.

Figure 8: Rectifying bridge.

This unit is based on the obsolete half-bridge topology using two 2SD209L power NPN transistors on its switching section. Each transistor is capable of handling up to 12 A at 25° C. Unfortunately the manufacturer does not provide the current limit at 100° C.

Figure 9: Switching transistors.

The switching transistors are controlled by an FSP3528 PWM controller, which is located on the secondary from the power supply. As you can see, this circuit is a half-bridge PWM controller that was relabeled by FSP and we are not sure of what circuit it is derived from (the pinout is different from other 20-pin half-bridge PWM controllers we know, like SD6109 and SG6105).

Figure 10: PWM controller.

The two electrolytic capacitors from the voltage doubler are from Teapo and labeled at 85° C.

Now let’s take a look at the secondary of this power supply.