We were very curious to check what components were chosen for the power section of this power supply and also how they were set together, i.e., the design used. We were willing to see if the components could really deliver the power announced by Cooler Master.
From all the specs provided on the databook of each component, we are more interested on the maximum continuous current parameter, given in ampères or amps for short. To find the maximum theoretical power capacity of the component in watts we need just to use the formula P = V x I, where P is power in watts, V is the voltage in volts and I is the current in ampères.
Keep in mind that this doesn’t mean that the power supply will deliver the maximum current rated for each component as the maximum power the power supply can deliver depends on the other components used – like the transformer, coils, the PCB layout and the wire gauge – not only on the specs of the main components we are going to analyze.
For a better understanding of what we are talking here, please read our Anatomy of Switching Power Supplies tutorial.
This power supply uses two U8KBA80R rectifying bridges in parallel in its primary stage. As each bridge supports up to 8 A continuous current, the maximum continuous current supported by the primary rectifying section of this power supply is 16 A. This stage is highly overspec'ed: at 115 V this unit would be able to pull up to 1,840 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,472 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.
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Figure 11: Rectifying bridges on this power supply.Rectifying bridges on this power supply.
On the switching section the main transistors used are two SPW20N60C3. These transistors have a maximum rated current of 13.1 A at 100º C in continuous mode or 62.1 A at 25º C in pulse mode each. They are connected using the two-transistor forward configuration.
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Figure 12: Main switching transistor.
In Figure 13, you can see the active PFC circuit controller board.
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Figure 13: Active PFC controller.
