Review of the Chieftronic SteelPower BDK-750FC 750 W power supply unit /


Today we have the Chieftronic BDK-750FC PSU on test, the older model in the SteelPower series, which also has 550 and 650 watt models. All of them have the 80 Plus Bronze certificate. This is a relatively budget series with modular cable connection, resonant LLC converter with synchronous rectifier and independent output voltage stabilization. The manufacturer also promises premium Japanese capacitors. Let’s evaluate how good he is.

Chieftronic SteelPower BDK-750FC

Chieftronic SteelPower 750W (BDK-750FC)

Model Chieftronic SteelPower BDK-750FC
Product page SteelPower BDK-750FC
Power, W 750
Certificate of energy efficiency 80 Plus Bronze
Form factor ATX
Cable connection diagram Modular
Channel power +12V, W (A) 750 (62,5)
Channel power +5V, W (A) 100 (20)
Channel power +3.3V, W (A) 66 (20)
Combined power +3.5V and +5V, W 120
Channel power – 12, W (A) 3,6 (0,3)
Channel power +5Vsb, W (A) 12,5 (2,5)
Active PFC +
Mains voltage range, V 100-240 V
Mains voltage frequency, Hz 47–63
Fan size, mm 120x120x25
Type of shaft Kulkova
Number of cables/connectors for CPU 1/2x EPS12V (4+4)
Number of cables/connectors for PCI-E 2/4x (6+2)
Number of cables/connectors for SATA 2/6
Number of cables/connectors for IDE 1/3
Number of cables/connectors for FDD 1/1
Protective functions OPP, OVP, UVP, SCP, OSR, OTP, SIP
Dimensions (WxHxD), mm 150x86x140
Warranty, month 60
Price n/a

The power supply comes in a medium-sized box with high-quality printing, which is used for all products in this series. On the front side there is a photo of the block, on the back side there is information about the technical characteristics of all SteelPower devices.

Chieftronic SteelPower BDK-750FCChieftronic SteelPower BDK-750FC

In addition to the unit itself, the delivery set includes a network cable, modular wires in a separate case, a bag with fasteners and instructions.

Chieftronic SteelPower BDK-750FC

Power supply unit with modular cables, their number and length are as follows:

  • one for powering the motherboard (65 cm);
  • one with two 8-pin (4+4) connectors for powering the processor (60+15 cm);
  • two with two 8-pin (6+2) connectors for powering a PCI-E video card (50+15 cm);
  • two with three connectors for powering SATA devices (50+15+15cm);
  • one with three power connectors for IDE devices and one FDD connector (50+15+15+15 cm).

All cables are made in the form of loops with black insulation, their length is quite long, it should be enough for cases with the lower location of the power supply unit.

Chieftronic SteelPower BDK-750FC

The body of the block is covered with black powder paint. The grille of the cooling fan is stamped, with a large number of partitions, which can negatively affect the level and nature of noise. There are black stickers on the side edges that organically fit into the appearance of the block. On the upper side there is a sticker with technical characteristics.

The unit is built on a modern CWT platform: with an active power factor corrector (APFC) and a wide input voltage range, with a power resonant LLC-converter and a synchronous rectifier on the +12 V line, as well as DC/DC converters for the +5 V lines and +3.3 V. Similar circuitry is used in “golden” power supplies.

A full-fledged impulse interference filter is unsoldered at the input, some of its elements are located on the network connector. The input rectifier is cooled by a small separate radiator, the power factor corrector is controlled by the CM6500UNX chip. The high-voltage filter is made on an electrolytic capacitor with a capacity of 390 μF and a voltage of 400 V with an operating temperature of 105 °C manufactured by Nichicon.

A pair of power transistors PTA20N50A (20 A, 500 V) of the resonant LLC converter are installed on a common radiator with APFC elements, the converter is controlled by the CM6901X microcircuit, which is located on a separate small board. The synchronous rectifier is made of four AP4N2R6 transistors (150 A, 40, 2.6 mΩ), which are unsoldered on the main board, two plates soldered next to each other are responsible for their cooling. The output voltage is filtered by six 470μF 16V polymer capacitors and a 3300μF 16V 105°C electrolytic capacitor from ChengX.

A step-down DC/DC converter assembled on a separate board is responsible for powering the +3.3 V and +5 V lines. A pair of 470 μF 16 V polymer capacitors are installed on it in the input circuit of the converter, a pair of chokes and a pair of polymer capacitors with a capacity of 1500 μF and an operating voltage of 6.3 V are located at the output. It was not possible to examine the type of controller and power switches, the back side of the board is covered by a screen .

Chieftronic SteelPower BDK-750FC

Polymer capacitors for additional filtering of output voltages are installed on the connection board of the modular cables: six at 470 μF 16 V and seven at 560 μF 6.3 V.

Chieftronic SteelPower BDK-750FC

The power converter of the standby mode is made on a PWM controller TNY287PG, at its output is installed an electrolytic Low ESR capacitor with a capacity of 2200 μF and a voltage of 10 V with an operating temperature of 105 °C manufactured by ChengX. All other capacitors in the block are also from ChengX and CapXon. Monitors the output voltage supervisor ST9S313-DAG from Sitronix.

Chieftronic SteelPower BDK-750FCChieftronic SteelPower BDK-750FC

A 120x120x25 mm fan marked HA1225H12F-Z (12 V, 0.58 A) and a two-pin connection is responsible for cooling the unit components. The fan is controlled automatically depending on the temperature of the transistors of the synchronous rectifier on the +12 V line. After turning on the unit to “cold”, the fan worked at 750 revolutions per minute and made almost no noise, with increasing temperature it should smoothly increase its speed to a maximum of 2200 rpm.

Chieftronic SteelPower BDK-750FC

The assembly and soldering are of high quality, the board is normally cleaned of flux.

Chieftronic SteelPower BDK-750FC

Testing methodology

The power supply unit was tested using a linear electronic load with the following parameters: current adjustment ranges on the +3.3 V line — 0–16 A, on the +5 V line — 0–22 A, on the +12 V line — 0–100 A , all contacts for connecting power supply cables with the same voltage are connected in parallel and loaded by the corresponding load channel. The current on each channel is smoothly regulated, and it is stable regardless of the output voltage of the unit. A Zotek ZT102 True RMS multimeter was used to accurately measure voltage and temperature. Fan revolutions were measured with a Uni-T UT372 tachometer. For each power line, the required current was set and the voltage on the load contacts was measured to account for losses on the wires.

Test results

The first test for the load capacity of the +12V main line, the current on the +3.3V and +5V lines was constant with a total load of about 120 W.

The load current on the +12V line, A The voltage on the line is +12 V, V Load power on the +12V line, W The voltage on the line is +5V at a current of 15 A Load power on the +5V line, W The voltage on the line is +3.3V at a current of 10 A Load power on the +3.3V line, W Total load power, W
0 12,12 0 5,02 75,3 3,32 46,5 121,8
10 12,12 121,2 5,02 75,3 3,32 46,5 243
20 12,12 242,4 5,02 75,3 3,32 46,5 364,2
30 12,11 363,3 5,02 75,3 3,32 46,5 485,1
40 12,10 484 5,02 75,3 3,32 46,5 605,8
50 12,09 604,5 5,01 75,1 3,31 46,3 725,9
55 12,09 665 5,01 75,1 3,31 46,3 786,4

According to the test results, we have excellent stabilization along all lines, which has already become the norm for all modern blocks with independent stabilization. There may be differences between the blocks only due to the quality of the wires, in this case the cables are of sufficient quality, the offsets are minimal.

A test of the load capacity of the +5V and +3.3V lines was made with a constant load of +12V to assess their influence on each other.

The load current on the +3.3V line, A The voltage on the line is +3.3V, V The load current on the +5V line, A The voltage on the line is +5V, V The load current on the +12V line, A The voltage on the line is +12V, V
0 3,34 0 5,03 15 12,12
0 3,34 5 5,02 15 12,12
0 3,34 10 5,02 15 12,12
0 3,34 15 5,01 15 12,12
5 3,33 0 5,03 15 12,12
10 3,32 0 5,03 15 12,12
15 3,31 0 5,03 15 12,12
15 3,32 15 5,01 15 12,12

According to the test results, we have good stabilization on the +3.3V and +5V lines, load distortions have almost no effect on the output voltage.

The unit efficiency test was carried out at a voltage of about 230 V.

Load power, % Load power, W Network current consumption, A Voltage in the network, V Efficiency, %
25 187 0,93 234 86
50 375 1,76 234 91
75 562 2,71 233 89
100 750 3,76 232 86

The efficiency of this device falls within the 80 Plus Bronze standard for a voltage of 230 V with a good margin, because in this design we have a slightly cheaper version of the budget “golden” block.

The heat test of the PSU components was performed at an indoor air temperature of 21 °C using a Scythe Kaze Master Pro panel, the sensors of which were fixed to the main components of the unit. The unit was loaded at maximum capacity and worked until the temperatures stabilized. At the end of the test, the temperature readings were fixed, after that the cover of the device was removed and the temperatures of other components were measured using a multimeter and its thermocouple. The test results are shown in the following photo of the block board:

Chieftronic SteelPower BDK-750FC

The temperatures of the components are generally not as high as for “bronze”, this is indicated by modern circuitry. Under prolonged maximum load, the cooling fan speed rose to 2020 rpm, while the unit was slightly noisier than other fans in the test bench. In the case of the PC, temperatures and noise will be different, it will all depend on the location of the unit, ventilation of the case and the temperature in the room.


The tested Chieftronic BDK-750FC gives all the declared characteristics with a good margin, built on a modern platform, which is usually used in “golden” power supplies, has excellent indicators of output voltage stability, quite high-quality wires, a good design, and even one Japanese capacitor. Build quality is good, but the element base is budget, including the rest of the capacitors. However, the manufacturer gives a guarantee of 60 months, apparently, with not very high heating, even Chinese capacitors live quite a long time. This unit is suitable for budget and medium-level systems – in this mode, the heating and noise level will be relatively low, and the unit will serve the stated warranty period without any problems.


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