SilverStone Strider ST50F 500 W Power Supply Review

Primary Analysis

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 100° 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.

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 25° C or 13.1 at 100° C in continuous mode, or up to 62.1 A at 25° 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 25° C or 7.6 at 100° C in continuous mode, or up to 48 A at 25° C in pulse mode). Once again we can’t tell about ZM460B-APS as we haven’t reviewed this unit yet.

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 25° C or 11A at 100° C or up to 72 A at 25° 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 25° C or 5.4 A at 100° C in continuous mode, or up to 36 A at 25° 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.

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.

Figure 14: PFC and PWM controller combo.