We were very curious to check what components were chosen for the power section of this power supply, especially because it uses the same project as Zalman ZM360B-APS and ZM460B-APS.

This power supply uses one GBU806 rectifying bridge in its primary stage, which can deliver up to 8 A (rated at 100º C). This bridge is attached to the same heatsink where the switching transistors are located. Zalman ZM360B-APS uses a GBU606 bridge, which can deliver less current (6 A). We can’t tell about ZM460B-APS as we haven’t reviewed this unit yet. This is more than adequate rating for a 500 W power supply. The reason why is that at 115 V this unit would be able to pull up to 920 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 736 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 bridge.

On the active PFC circuit two 20N60C3 power MOSFET transistors are used, each one capable of handling up to 20.7 A at 25º C or 13.1 at 100º C in continuous mode, or up to 62.1 A at 25º C in pulse mode. These transistors are located on a separated heatsink, together with the active PFC diode. Zalman ZM360B-APS uses two STP14NK50ZFP, which are capable of handling less current (14 A at 25º C or 7.6 at 100º C in continuous mode, or up to 48 A at 25º C in pulse mode). Once again we can’t tell about ZM460B-APS as we haven’t reviewed this unit yet.

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Figure 12: Active PFC transistors and diode.

On the switching section this power supply uses two STF21NM50N power MOSFET transistors in two-transistor forward configuration. Each one of these transistors can deliver up to 18 A at 25º C or 11A at 100º C or up to 72 A at 25º C in pulse mode, which is the mode used. Here again the components were upgraded, as Zalman ZM360B-APS uses two FQPF9N50C, which can deliver less current (9 A at 25º C or 5.4 A at 100º C in continuous mode, or up to 36 A at 25º C in pulse mode). Once again we can’t tell about ZM460B-APS as we haven’t reviewed this unit yet. As mentioned, these transistors are located on the same heatsink as the rectifying bridge.

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Figure 13: Switching transistors.

The primary section is controlled by a CM6800 integrated circuit, which is a very popular active PFC and PWM controller combo. It is located on a small printed circuit board attached to the main board.

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Figure 14: PFC and PWM controller combo.