A Look Inside

Before reading this page we strongly suggest to take a look at this article, which will help you understand the internal components of a PSU much better.


The main PCB features a very clean layout, without wires taking over all the space and the design used is completely different from what we see in most of today's PSUs. Enermax instead of putting the APFC and the primary on the left side of the PCB and the secondary on the right side, chose to house the APFC/primary side on the first front half of the board while the secondary side takes over the rest of the PCB. Using this layout they managed to keep airflow at good levels thanks to the specially designed heatsinks while the main advantage is the reduced heat dissipation since the secondary side is now very close to the modular PCB. A plain simple but clever idea.


The AC receptacle incorporates a line EMI filter, YO15T1, provided by Yunpen. On its terminals we also find two Y caps. On the main PCB we meet the rest of the transient filtering stage, three CM chokes, one X and two Y caps and an MOV.


The main PCB is connected to the main switch through two crimp terminals. This makes the removal of the PCB a breeze.


The single, powerful, bridge rectifier is provided by Shindengen and its model number is LL25XB60. In front of it resides the large APFC choke.


To the far left heatsink four FQA 24N50 mosfets are bolted, two on each side. These are used by the APFC circuit along with a boost diode.


The three parallel caps (330μF, 400V, 105°C, HC series) are provided by Panasonic/Matsushita. Their combined capacity is 990μF.


On the heatsink in front of the hold up caps we find the main switchers, four MDF18N50 mosfets. The topology utilized by this unit is Zero Voltage Switching (ZVS) Phase-Shifted Full-Bridge. It's a state of the art topology which offers the best efficiency possible since it minimizes energy losses on the main switches.


Between the APFC and the primary heatsink resides the NTC thermistor responsible for inrush current protection and the electromagnetic relay which cuts it off the circuit, once its job finishes.


On the left side of the main PCB we find two small vertical boards. The right one houses the PFC controller, an ICE2PCS01 and a LM393 voltage comparator which assists in overvoltage and undervoltage protection. On the left board resides a UCC28950 IC which is the controller responsible for the main switchers. The second IC on this board is a UCC27324, a high speed low-side power mosfet driver.


In front of the primary heatsink there is the high density main transformer and right in front of it the secondary heatsink which holds six IRFB3004 mosfets. Two large toroidal chokes are used to rectify/filter +12V. In front of the chokes there are ten Rubycon filtering caps (1500μF, 16V, 105°C, ZLK series).


The +12V rail is transferred to the modular PCB through eight bus bars which Enermax calls copper-bridge transmission array. These bars substantially increase conduction thus decrease voltage drops. The shunt resistors, used by OCP, are soldered on the bottom side of the modular PCB.


The VRMs that generate the minor rails are housed on the modular PCB. In each one we find an APW7073A PWM controller and four APM2556N mosfets.


On the face of the modular PCB resides the protections IC, a PS238 which provides OCP for up to six +12V channels, matching this way the virtual rails that the unit has.


The 5VSB circuit is controlled by a TOPSwitch-JX TOP265 integrated of-line switcher which provides high efficiency at standby.


On the solder side of the main PCB we were quite satisfied by the soldering quality in general, although we spotted some rather long component leads. In the second photo above you see the large copper plate which enhances the PCB's conductivity in the +12V area thus decreasing voltage drops especially in cases where high currents pass through. Finally, as it seems Lora signed this PCB.


The cooling fan has an Enermax logo on it and its model number is ED142512S-DA (139mm, 12V, 0.6A, 900 ~ 2000rpm). It features twister bearings for increased lifespan and at low RPM it's fairly quiet.