Be Quiet Dark Power Pro 10 550 W 8

Be Quiet Dark Power Pro 10 550 W

Voltage Regulation & Efficiency »

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 OEM of this unit is FSP and this is a new design from them. This platform uses a half bridge topology in the primary side along with an LLC resonant converter to boost efficiency and in the secondary synchronous rectification is used along with two DC-DC converters (or VRMs) for the generation of the minor rails. So all modern tricks are utilized in this design to provide the best possible performance and efficiency. Finally as you can see the PCB is quite large for the mere 550W capacity of this unit.


The transient filtering stage (or EMC/EMI filtering stage) starts right at the AC receptacle with one X and two Y caps. On the main PCB we find the remaining components: two CM chokes, one X and two Y caps and an MOV. This is one of the rare occasions that we meet an FSP made unit that features an MOV! Also in this section resides the thermistor responsible for protection against large inrush currents and the relay that cuts it off the circuit once it finishes its job.


The single bridge rectifier is bolted on a heatsink and its model number is LL15XB60.


Be Quiet states that they used a special high quality, plastic, capacitor to minimize the high-frequency noises coming out of the PFC stage.


In the APFC three STF22NM60N fets are used along with the necessary boost diode. The two parallel hold up caps are provided by Matsushita/Panasonic (220μF each or 440μF combined, 450V, 105°C).


As main choppers two STF22NM60N fets are used in a half-bridge topology. A resonant converter boosts efficiency by allowing loss-less switching of the main switchers.


The PFC controller is installed onto this small vertical PCB. Its model number is NCP1654B. The LLC resonant and PWM controller is installed on another vertical PCB and it is provided by Champion (CM6901).


In the secondary side synchronous rectification is used and the +12V generate four IRFB3206G fets. In the secondary we find also many polymer caps, provided by Capxon and some Nippon Chemi-Con electrolytics.


The minor rails are generated by two VRMs which are installed on the same PCB. The main PWM controller is an ANPEC APW7156 IC and each rail regulate four mosfets.


The protections IC is a SITI PS232F and it supports OCP for up to four +12V rails, matching this way the specifications of this unit.


On the front of the modular PCB we find many polymer Capxon caps for ripple filtering and a single electrolytic one. Also there are a sensor and a transistor (UTC MJE2955TL) on this PCB which are used for the temperature control of the external fans, making them electrically independent from the internal fan.


Soldering quality on the main PCB is quite good although not as good as the high-end implementations of the competition. Apparently the production still hasn't been perfected and some last minute touch ups had to be made on the main PCB.


The cooling fan features Fluid Dynamic Bearing and its model number is BQT T13525-LF15 (12V, 0.22A, 1500RPM max). This is a high quality fan which can last for up to 300,000 hours, according to Be Quiet and it is inaudible at any time.
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