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 Antec.

From all the specs provided on the databook of eachcomponent, 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 a GBU1006 rectifying bridge in its primary stage, which can deliver up to 10 A of continuous current. This component 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.

click to enlarge
Figure 10: Rectifying bridge on this power supply.

On its primary stage, four power MOSFET transistors are used, two 20N60C3 for the active PFC circuit (20 A maximum at 110º C each) and two FQA18N50V2 (12.7 A maximum at 100º C each) for the switching section, which uses a two-transistor forward configuration. For a better understanding on the relationship between these transistors, we drew a simplified diagram of this section of the NeoPower 550 power supply, see Figure 11.

click to enlarge
Figure 11: Simplified diagram of this power supply showing the location of the four MOSFET transistors.

click to enlarge
Figure 12: MOSFET transistors used on this power supply.

The primary is controlled by a CM6800 integrated circuit, which is an active PFC and PWM controller combo. It is located on a small printed circuit board shown in Figure 13.

click to enlarge
Figure 13: Active PFC and PWM controller integrated circuit.