Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the insides of a PSU better.



This is CWT's new GPX platform; it uses a full-bridge topology and an LLC resonant converter on the primary side. On the secondary side, we find FETs regulating the +12 V rail, and a pair of VRMs for the generation of the minor rails. The design is nice, leaving lots of space on the secondary side for increased airflow. The heatsinks on the primary side are medium-sized, while the +12 V heatsinks are relatively small. Full-bridge topologies can deliver higher power output compared to half-bridge ones if proper components are installed. That said, the latter emits less radiated EMI.

I would like to see a stronger boost diode in the APFC converter and higher quality switching FETs. These changes would notably increase the production cost, however.


The transient filter is complete and does a very good job filtering out both incoming and outgoing EMI emissions.


A discharge IC disconnects the bleeding resistors the transient filter's X caps use, providing a small efficiency boost.


It is always nice to find an MOV and an NTC thermistor supported by a bypass relay.


The single bridge rectifier is bolted to a thick heatsink so that it can reach its full potential.


The APFC converter uses two Great Power GP28S50 FETs and a boost diode by On Semiconductor with 6 A maximum current handling at 153 °C. For comparison, the Corsair RM850x (2018) uses a CREE C3D08060A (600 V, 8 A @ 152 °C). The bulk cap should be of higher quality as well, and rated at 105 °C.


The APFC controller consists of a Champion CM6500, and the CM03X by the same manufacturer is also used to restrict vampire power.


Four Silan Microelectronics FETs are arranged into a full-bridge topology. The LLC resonant controller handling them and the +12 V FETs is the omnipresent Champion CM6901X.


The main transformer of the PSU.


All six FETs that regulate +12 V are installed on the solder side of the PCB. The heatsinks on the other side of the PCB help with their cooling.


The filtering caps on the secondary side are not of high quality. They should at least use Elite caps if they want a low price and decent reliability. Thankfully, there are plenty of polymer caps on board, which are tolerant to high operating temperatures.


Two DC-DC converters generate the minor rails. The joint PWM controller is an ANPEC APW7159C.


The standby circuit uses a Power Integrations TNY287PG PWM controller.


The supervisor IC is a Sitronix ST9S429-PG14, which supports all the necessary protection features but OTP. The latter is implemented through another circuit.


Some bus bars transfer power to the modular sockets. Several polymer caps are used to reduce ripple further.


Soldering quality is good, which usually is the case with implementations from CWT.


The cooling fan is provided by Yate Loon and uses double ball bearings. This is a strong fan driven by a relaxed speed profile.