PC Power & Cooling Silencer 610 EPS12V Power Supply Review

Secondary Analysis

This power supply uses four Schottky rectifiers on its secondary.

The +12 V output uses two 30A50CT in parallel, each one capable of handling up to 30 A at 125° C (15 A per internal diode). The maximum theoretical current the +12 V line can deliver is given by the formula I / (1 – D), where D is the duty cycle used and I is the maximum current supported by the rectifying diode (which in this case is made by two 15 A diodes in parallel). Just as an exercise, we can assume a typical duty cycle of 30%. This would give us a maximum theoretical current of 43 A or 514 W for the +12 V output. The maximum current this line can really deliver will depend on other components, in particular the coil used.

The +5 V output uses one 30L30CT, which is capable of handling up to 30 A at 140° C (15 A per internal diode). The maximum theoretical current the +5 V line can deliver is given by the formula I / (1 – D), where D is the duty cycle used and I is the maximum current supported by the rectifying diode (which in this case is made by one 15 A diode). Just as an exercise, we can assume a typical duty cycle of 30%. This would give us a maximum theoretical current of 21 A or 107 W for the +5 V output. The maximum current this line can really deliver will depend on other components, in particular the coil used.

The +3.3 V output uses one 30A40CT, capable of handling up to 30 A at 135° C (15 A per internal diode). Using the same math the +3.3 V output would have a maximum theoretical power of 71 W.

Even though this power supply has a separated rectifier for the +3.3 V output, this rectifier is connected to the same transformer output as the +5 V line, so the maximum current +5 V and +3.3 V can pull together is limited by the transformer.

As we said earlier, the maximum power the power supply can deliver depends on other components used – like the transformer, coils, the PCB layout, the wire gauge and even the width of the printed circuit board traces. The numbers presented are just a theoretical exercise.

Figure 10: The four Schottky rectifiers used on the secondary.

This power supply uses a tiny semiconductor thermal sensor located on the solder side of the printed circuit board, under the secondary heatsink (see Figure 11). This sensor may go unnoticed by an untrained eye. The purpose of this sensor is controlling the speed from the power supply fan.

Figure 11: Thermal sensor.

This power su
pply uses a mix of Japanese (Chemi-Con) and Taiwanese (OST) electrolytic capacitors. The big electrolytic capacitor from the active PFC circuit is rated at 85° C while all other smaller capacitors are rated 105° C.