Introduction

We would like to thank Raijintek for supplying the review sample.


Raijintek entered the PSU market with an SFX line featuring 450 W and 550 W capacity units. I will take a look at the Ermis 550B in this review. Let me start by saying that since I am Greek, I like the naming scheme of all Raijintek products based on Greek mythology. For those of you unaware, Ermis (Ερμής or Hermes) is an Olympian god, the protector of heralds, travelers, thieves, merchants, and orators. He is also incredibly fast. The Flash DC character and Hermes share many similarities since both are so very fast.

The Ermis 550B is 80 PLUS Bronze and Cybenetics Silver certified. It also has the Cybenetics A- noise certification. Raijintek used a non-modular cable configuration to reduce cost, which will probably disappoint some. That said, there are only a few cables because of the small form factor and low capacity. The specifications include an 80 mm sleeve bearing fan and the three-year warranty. The OEM behind both Ermis units is Casecom, which also makes many Kolink and Aerocool units.

Specifications

Photos

The box is small, and at its face is the PSU with its fixed cables meticulously hidden.


Protection inside the box is adequate.


It is nice to find an SFX to ATX adapter bracket in the bundle for installing the PSU into standard ATX cases.


The typical honeycomb-style exhaust grille is used. Unfortunately, there is no power switch.


The power specifications label is on one of two sides.


The cables are fixed, but flat.


The pile of fixed cables looks large against the small PSU.


Some more photos of the PSU from various angles.

Cables and Connectors

This is an SFX PSU and, as such, for small cases, so all of its cables are short. The distance between all connectors is long enough, especially for the peripheral connectors. Because of the low capacity, there is only one EPS connector accompanied by a pair of PCIe connectors.


Three SATA connectors are enough for a small system. I would like to see just as many 4-pin Molex.

Component Analysis

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



The OEM is Casecom. Under proper guidance, this OEM is capable of delivering good high performance per dollar products. The PCB is small since this it is an SFX unit. The heatsinks are not that large, and there is enough clearance between the parts for adequate airflow. The fixed cables don't significantly get in the way of airflow for the filtering caps on the secondary side, which increases their lifetime. The main issue with fixed cables on PSUs is that many wires traverse the secondary side, messing with airflow. This is one of the main reasons I prefer modular PSUs over non-modular ones. Build quality is decent for this price range. The design is a mix of old and new elements. We find an older design with a double-forward topology on the primary side. In contrast, on the secondary side, we have a synchronous design with DC-DC converters to generate the minor rails. Thankfully, Casecom didn't use passive parts for the +12 V rail's rectification, which would lead to increased energy losses.


The transient filter starts on the AC receptacle and continues on the main PCB. There is no MOV to handle voltage surges, which is a big shame.


An NTC thermistor lowers inrush currents. There is no bypass relay to support it. To save money, no such relay is usually installed in Bronze or Silver PSUs.


The single bridge rectifier can handle up to 8 A. For 230 V input, there won't be any problems, but there is not much room left for 100 V input.


The APFC converter uses three First Semiconductor FETs and a strong WeEn Semiconductor boost diode. The bulk caps are by HCON and offer 440 uF combined capacity. They are rated at 105°C, which is the only specification for these I could find. There is no information on the expected lifetime at 105°C.


A blast from the past, the common APFC and PWM controller is a Champion CM6800UX.


The two PTA20N50A primary switching FETs are installed in a double-forward topology.


The main transformer is next to the standby transformer.


Three FETs regulate the +12 V rail.


The electrolytic caps on the secondary side are by Asia'x. There are also three polymer caps.


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


The standby PWM controller is an SC2521Q.


The supervisor controller is a Grenery GR8313.


Soldering quality is decent.


The cooling fan is from an unknown brand. It measures 80 mm across and uses a sleeve bearing.

Test Setup