Teardown & Component Analysis
Before proceeding with this page we strongly encourage you to a look at our PSUs 101 article, which provides valuable information about PSUs and their operation, allowing you to better understand the components we're about to discuss. Our main tools for disassembling PSUs are a Thermaltronics soldering and rework station and a Hakko FR-300 desoldering gun. Finally, for the identification of tiny parts we use an Andonstar HDMI digital microscope.
|Manufacturer (OEM)||Great Wall|
|Transient Filter||4x Y caps, 2x X caps, 2x CM chokes, 1x MOV|
|Inrush Protection||NTC Thermistor|
|Bridge Rectifier(s)||2x GBU1508 (800V, 15A @ 100°C)|
|APFC MOSFETs||2x Vishay SiHG30N60E (650V, 18A @ 100°C, 0.125Ω)|
|APFC Boost Diode||1x BYC15-600 (600V, 15A @ 98°C)|
|Hold-up Cap(s)||2x Chemi-Con (450V, 180uF each, 2000h @ 105°C, KMR)|
|Main Switchers||2x ROHM Semiconductor R6020ANX (600V, 9.7A @ 100°C, 0.22Ω)|
|APFC Controller||Champion CM6500 & CM03AX Green PFC Controller|
|LLC Resonant Controller||Champion CM6901X|
|Topology||Primary side: Half-Bridge & LLC Resonant Controller Secondary side: Synchronous Rectification & DC-DC converters|
|+12V MOSFETs||4x APEC AP9992GP-A-HF (60V, 115A @ 100°C, 2.99mΩ)|
|5V & 3.3V||DC-DC Converters: 6x Alpha & Omega AOD508 (30V, 55A @ 100°C, 4.5mΩ) PWM Controller: APW7159C|
|Filtering Capacitors||Electrolytics: Nippon Chemi-Con (1-5,000 @ 105°C, KZE), Rubycon ZLH (6-10,000h @ 105°C), Rubycon ZLJ (1-5,000h @ 105°C), 1x Elite (4.7uF, 50V, 105°C) Polymers: 10x Chemi-Com|
|Supervisor IC||Sitronix ST9S429-PG14 (OCP, OVP, UVP, SCP, PG) & LM358|
|Fan Model||Yate Loon D12SM-12 (120mm, 12V, 0.30A, 1650RPM, 70.5 CFM, 33 dB(A), Sleeve Bearing)|
|FET & Rectifier||1x APEC AP04N60H-HF (600V, 2.2A @ 100°C, 2.5Ω) & 1x PFR20L45CT SBR (45V, 20A)|
|Standby PWM Controller||Leadtrend LD5760|
Upon removing this PSU's top panel, we got the impression that Riotoro's PR-BP0650-SM should sport a higher efficiency rating. That's because Great Wall uses a half-bridge topology, along with an LLC resonant converter on the primary side. On the secondary side, we find a synchronous design and DC-DC converters. Similar platforms are normally utilized in much higher-efficiency PSUs, so this is a nice surprise.
Continuing with the good news, almost all of this platform's capacitors are provided by respected Japanese manufacturers (Chemi-Con and Rubycon), and although most of them don't belong to high-end lines, they still outperform the Taiwanese and Chinese caps typically used in similarly-priced PSUs. In general, this looks to be a very good platform that should be highly competitive.
The first part of the transient filtering stage is on a small PCB; it includes a single X cap and two Y ones. The same filter continues on the main PCB with another round of the same caps, in addition to two CM chokes and an MOV.
An NTC thermistor provides protection against large inrush currents. The only problem is that there is no bypass relay to support it, so it remains in the circuit once the PSU's start-up phase finishes. This won't allow its temperature to drop, which would allow it to offer its services again in the event of a short power loss draining the bulk caps. On top of that, even at high temperatures this thermistor still has some resistance, so energy is lost on it.
Two GBU1508 bridge rectifiers are bolted on a dedicated heat sink.
We find two Vishay SiHG30N60E FETs and a single BYC15-600 boost diode in the APFC converter. The bulk caps are provided by Chemi-Con (450V, 180uF each, 2000h @ 105°C, KMR), and although their quality is high, their combined capacity (360mF) is very low for a 650W PSU. The PFC controller is installed on the main PCB; it is a Champion CM6500, and it's supported by a CM03AX Green PFC controller.
The primary FETs are two ROHM Semiconductor R6020ANXs arranged into a half-bridge topology. The LLC resonant controller, a Champion CM6901X, is on the solder side of the main PCB. It's weird to see an LLC resonant controller in a PSU with such low efficiency certifications. GW probably had to try hard to achieve this.
Here's the LLC resonant part and a small detail on the board, an arrow shape showing the direction of soldering.
Four APEC AP9992GP-A-HF FETs regulate the +12V rail. On their heat sink, we also notice a thermistor that most likely provides data to the fan control circuit.
The majority of filtering caps is provided by Chemi-Con (KZE) and Rubycon (ZLH, ZLJ). We only spot a single Elite electrolytic capacitor, it likely doesn't play a great role in filtering. All electrolytic caps are rated at 105°C, and 10 polymer Chemi-Cons also filter the rails. They're mostly installed on the front side of the modular PCB.
The modular PCB is quite small, but it's fully equipped with ripple-filtering caps.
The supervisor IC, a Sitronix ST9S429-PG14, is supported by a LM358 IC.
We don't have any complaints about Great Wall's soldering quality. It's actually quite good.
The cooling fan is provided by Yate Loon and it uses a single sleeve bearing. Its model number is D12SM-12 (120mm, 12V, 0.30A, 1650 RPM, 70.5 CFM, 33 dB[A]). Although we would like to see a higher-quality fan, you can't be too picky in this price range.
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