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[nextpage title=”Introduction”]

From time to time we like to test power supplies from obscure brands or from brands that are popular in other countries but not in the United States. This is the case today, with our review of the AK 500 power supply from the South Korean 3R System. Let’s see if this power supply is a viable option or if it is a piece of Chinese garbage with a South Korean passport.

Compared to the iCEAGE IA500HP80 from the same manufacturer, the AK 500 starts off on the right foot, as it has active PFC and standard 80 Plus certification, which are not present on the IA500HP80.

3R System AK 500 power supplyFigure 1: 3R System AK 500 power supply

3R System AK 500 power supplyFigure 2: 3R System AK 500 power supply

The 3R System AK 500 is 5.5” (140 mm) deep, using a 120 mm sleeve bearing fan on its bottom (Yate Loon D12SM-12).

This unit doesn’t have a modular cabling system. All cables are protected with nylon sleeves, which come from inside the unit. This power supply comes with the following cables:

  • Main motherboard cable with a 20/24-pin connector, 17.3” (44 cm) long
  • One cable with two ATX12V connectors that together form an EPS12V connector, 24.4” (62 cm) long
  • Two cables, each with one six/eight-pin connector for video cards, 17.3” (44 cm) long
  • Two cables, each with three SATA power connectors, 14.2” (36 cm) to the first connector, 5.9” (15 cm) between connectors
  • One cable with three standard peripheral power connectors and one floppy disk drive power connector, 18.1” (46 cm) to the first connector, 5.9” (15 cm) between connectors

All wires are 18 AWG, which is the minimum recommended gauge, except for the video card cables, which use thicker 16 AWG wires, which is unusual to be seen in an entry-level product.

The cable configuration is very good for an entry-level 500 W product, with six SATA power connectors and two video card power connectors.

3R System AK 500 power supplyFigure 3: Cables

Let’s now take an in-depth look inside this power supply.

[nextpage title=”A Look Inside the 3R System AK 500″]

We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our “Anatomy of Switching Power Supplies” tutorial to understand how a power supply works and to compare this power supply to others.

On this page we will have an overall look, and then in the following pages we will discuss in detail the quality and ratings of the components used.

3R System AK 500 power supplyFigure 4: Top view

3R System AK 500 power supplyFigure 5: Front quarter view

3R System AK 500 power supplyFigure 6: Rear quarter view

3R System AK 500 power supplyFigure 7: The printed circuit board

[nextpage title=”Transient Filtering Stage”]

As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil. 

In this stage, this power supply is flawless, with one X capacitor, two Y capacitors, and one ferrite coil more than the minimum required.

3R System AK 500 power supplyFigure 8: Transient filtering stage (part 1)

3R System AK 500 power supplyFigure 9: Transient filtering stage (part 2)

On the next page, we will have a more detailed discussion about the components used in the 3R System AK 500.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the 3R System AK 500. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses one U15K80R rectifying bridge, which is not attached to a heatsink. This bridge supports up to 15 A at 100° C, so in theory, you would be able to pull up to 1,725 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,380 W without burning itself out. Of course, we are only talking about this particular component. The real limit will depend on all the components combined in this power supply.

3R System AK 500 power supplyFigure 10: Rectifying bridge

The active PFC circuit uses two MDF18N50 MOSFETs, each supporting up to 18 A at 25° C or 11 A at 100° C in continuous mode (note the difference temperature makes), or 72 A at 25&deg
; C in pulse mode. These transistors present a 220 mΩ resistance when turned on, a characteristic called RDS(on). The lower the number the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.

3R System AK 500 power supplyFigure 11: The active PFC diode and transistors

The output of the active PFC circuit is filtered by a capacitor from Samxon, labeled at 105° C.

In the switching section, another two MDF18N50 MOSFETs are used in the traditional two-transistor forward configuration. The specifications for these transistors were discussed above.

3R System AK 500 power supplyFigure 12: The switching transistors

The primary is controlled by a CM6805 active PFC/PWM combo controller.

3R System AK 500 power supplyFigure 13: Active PFC/PWM combo controller

Let’s now take a look at the secondary of this power supply.

[nextpage title=”Secondary Analysis”]

The 3R System AK 500 uses a regular design in its secondary, with Schottky rectifiers.

The maximum theoretical current each line can deliver is given by the formula I / (1 – D) where D is the duty cycle used and I is the maximum current supported by the rectifying diode. As an exercise, we can assume a duty cycle of 30 percent.

The +12 V output uses two PFR60L60CT Schottky rectifiers (60 A, 30 A per internal diode at 100° C, 0.65 V maximum voltage drop). This gives us a maximum theoretical current of 86 A or 1,029 W for the +12 V output.

The +5 V output uses two FCH30A10 Schottky rectifiers (30 A, 15 A per internal diode at 105° C, 0.88 V maximum voltage drop). This gives us a maximum theoretical current of 43 A or 214 W for the +5 V output.

The +3.3 V output uses two PFR30L45CT Schottky rectifiers (30 A, 15 A per internal diode at 100° C, 0.52 V maximum voltage drop). This gives us a maximum theoretical current of 43 A or 141 W for the +3.3 V output.

3R System AK 500 power supplyFigure 14: The +3.3 V, +12 V, and +5 V rectifiers

This power supply uses a GR8323 monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), over current (OCP), and over temperature (OTP) protections. This chip offers two +12 V OCP channels.

3R System AK 500 power supplyFigure 15: Monitoring circuit

The electrolytic capacitors that filter the outputs are from Kingcon and labeled at 105° C, as usual.

[nextpage title=”Power Distribution”]

In Figure 16, you can see the power supply label containing all the power specs.

3R System AK 500 power supplyFigure 16: Power supply label

This power supply has two +12 V rails. We could clearly confirm this by the presence of two “shunts,” one for each +12 V rail, and the monitoring integrated circuit supports two +12 V over current protection channels. Click here to understand more about this subject.

3R System AK 500 power supplyFigure 17: The two +12 V shunts

The two rails are distributed as follows:

  • +12V1: ATX12V/EPS12V connectors and main motherboard cable
  • +12V2: All other connectors

This is a typical distribution for power supplies with two +12 V rails.

How much power can this unit really deliver? Let’s find out.

[nextpage title=”Load Tests”]

We conducted several tests with this power supply, as described in the article, “Hardware Secrets Power Supply Test Methodology.”  

First we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each load.

If you add all the powers listed for each test, you may find a different value than what is posted under “Total” below. Since each output can have a slight variation (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. In the “Total” row, we are using the real amount of power being delivered, as measured by our load tester.

The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test, the +12VA input was connected to the power supply +12V1 and +12V2 rails, while the +12VB input was connected to the power supply +12V1 rail.

Input Test 1 Test 2 Test 3 Test 4 Test 5
+12VA 4 A (48 W) 7 A (84 W) 10.5 A (126 W) 14 A (168 W) 17.5 A (210 W)
+12VB 4 A (48 W) 7 A (84 W) 10.5 A (126 W) 14 A (168 W) 17.5 A (210 W)
+5 V 1 A (5 W) 2 A (10 W) 4 A (20 W) 6 A (30 W) 8 A (40 W)
+3.3 V 1 A (3.3 W) 2 A (6.6 W) 4 A (13.2 W) 6 A (19.8 W) 8 A (26.4 W)
+5VSB 1 A (5 W) 1 A (5 W) 1.5 A (7.5 W) 2 A (10 W) 2.5 A (12.5 W)
-12 V 0.5 A (6 W) 0.5 A (6 W) 0.5 A (6 W) 0.5 A (6 W) 0.
5 A (6 W)
Total 102.8 W 195.6 W 300.4 W 403.0 W 503.4 W
% Max Load 20.6% 39.1% 60.1% 80.6% 100.7%
Room Temp. 46.5° C 45.3° C 45.0° C 45.6° C 48.6° C
PSU Temp. 49.4° C 49.4° C 49.6° C 51.8° C 53.8° C
Voltage Regulation Pass Pass Pass Pass Pass
Ripple and Noise Pass Pass Pass Pass Pass
AC Power 124.7 W 230.5 W 355.6 W 487.3 W 632.0 W
Efficiency 82.4% 84.9% 84.5% 82.7% 79.7%
AC Voltage 117.9 V 116.4 V 115.1 V 114.0 V 111.7 V
Power Factor 0.952 0.975 0.985 0.988 0.990
Final Result Pass Pass Pass Pass Pass

The 3R System AK 500 can really deliver its labeled wattage at high temperatures.

Efficiency was between 82.7% and 84.9% when we pulled between 20% and 80% of the power supply labeled wattage (i.e., between 100 W and 400 W). These are terrific numbers for an entry-level power supply. At full load, however, efficiency dropped a little bit below the 80% mark, at 79.7 percent. This is very common, as we test power supplies at very high temperatures (between 45° and 50° C), while the 80 Plus certification tests are performed at 23° C, and efficiency drops with the temperature.

Interestingly, this unit officially received the 80 Plus Bronze certification, but the manufacturer decided to sell it as a standard 80 Plus unit. This was a very honest move, as this product can’t provide 82% efficiency at real-world temperatures.

Voltages were closer to their nominal values (3% regulation) during tests three through five, which is great. During test one, the +5 V and +12 V outputs were outside this tighter range (at +5.19 V and +11.61 V, respectively), but still inside the allowed margin. During test two, only the +5 V output was outside this tighter range (at +5.15 V), but again, inside the allowed margin. The ATX12V specification states that positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values.

Let’s discuss the ripple and noise levels on the next page.

[nextpage title=”Ripple and Noise Tests”]

Voltages at the power supply outputs must be as “clean” as possible, with no noise or oscillation (also known as “ripple”). The maximum ripple and noise levels allowed are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures. We consider a power supply as being top-notch if it can produce half or less of the maximum allowed ripple and noise levels.

The 3R System AK 500 provided ripple and noise levels inside the appropriate range, as you can see in the table below.

Input Test 1 Test 2 Test 3 Test 4 Test 5
+12VA 32.4 mV 26.4 mV 33.4 mV 49.0 mV 83.2 mV
+12VB 32.2 mV 26.8 mV 32.2 mV 49.8 mV 82.6 mV
+5 V 14.2 mV 16.6 mV 20.8 mV 27.4 mV 39.6 mV
+3.3 V 16.4 mV 17.6 mV 20.4 mV 24.6 mV 28.8 mV
+5VSB 16.2 mV 16.6 mV 18.8 mV 21.4 mV 24.6 mV
-12 V 60.4 mV 57.6 mV 61.4 mV 71.4 mV 89.4 mV

Below you can see the waveforms of the outputs during test five.

3R System AK 500 power supplyFigure 18: +12VA input from load tester during test five at 503.4 W (83.2 mV)

3R System AK 500 power supplyFigure 19: +12VB input from load tester during test five at 503.4 W (82.6 mV)

3R System AK 500 power supplyFigure 20: +5V rail during test five at 503.4 W (39.6 mV)

3R System AK 500 power supplyFigure 21: +3.3 V rail during test five at 503.4 W (28.8 mV)

Let’s see if we can pull more than 500 W from this unit.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. We couldn’t pull more than that because the power supply shut down, showing that its protections were working well. During this test, all voltages were still inside the tighter 3% regulation, but ripple and noise levels at the +12 V, -12 V, and +5 V outputs were touching or slightly surpassing the maximum allowed levels at 122.3 mV, 115.6 mV, and 53.4 mV, respectively.

Input Overload Test
+12VA 20 A (240 W)
+12VB 20 A (240 W)
+5 V 10 A (50 W)
+3.3 V 10 A (33 W)
+5VSB 3 A (15 W)
-12 V 0.5 A (6 W)
Total 589.4 W
% Max Load 117.9%
Room Temp. 43.4° C
PSU Temp. 46.4° C
AC Power 752 W
Efficiency 78.4%
AC Voltage 110.0 V
Power Factor 0.990

[nextpage title=”Main Specifications”]

The main specifications for the 3R System AK 500 power supply include:

  • Standards: ATX12V 2.3
  • Nominal labeled power: 500 W
  • Measured maximum power: 589.4 W at 43.4° C ambient
  • Labeled efficiency: 80 Plus Bronze certification (officially), downgraded to standard 80 Plus by the manufacturer
  • Measured efficiency: Between 79.7% and 84.9%, at 115 V (nominal, see complete results for actual voltage)
  • Active PFC: Yes
  • Modular Cabling System: No
  • Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form an EPS12V connector
  • Video Card Power Connectors: Two six/eight-pin connectors on separate cables
  • SATA Power Connectors: Six on two cables
  • Peripheral Power Connectors: Three on one cable
  • Floppy Disk Drive Power Connectors: One
  • Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over current (OCP), over power (OPP), over temperature (OTP), and short-circuit (SCP) protections

  • Are the above protections really available? Yes
  • Warranty: NA
  • More Information: https://www.3rsys.com
  • MSRP: NA

[nextpage title=”Conclusions”]

The 3R System AK 500 is an honest entry-level power supply. If you are looking for an inexpensive 500 W unit and you can find this unit for sale in your country, it may be a good option, as long as the price is right (e.g., lower than 500 W 80 Plus Bronze units from OCZ). It provides very good efficiency for its class (between 79.7% and 84.9%), voltages closer to their nominal values than required most of the time, and ripple and noise levels within the proper range.

Here we have to give kudos to 3R System, as this power supply got the 80 Plus Bronze certification, and the manufacturer decided to downgrade it to the standard 80 Plus, as the unit can’t provide 82% minimum efficiency at real-world temperatures. It would be really nice if other manufacturers followed this basic principle of honesty with consumers.