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[nextpage title=”Introduction”]

The Huntkey Win7 6600, also known as LW-6600HGB, is a 500 W power supply, so we can’t understand where the “6600” in its name comes from. It has an active PFC circuit, but no 80 Plus certification, even though it presented efficiency above 80% on our tests. Let’s check it out.

Huntkey Win7 6600 power supplyFigure 1: Huntkey Win7 6600 power supply

Huntkey Win7 6600 power supplyFigure 2: Huntkey Win7 6600 power supply

The Huntkey Win7 6600 is 5.5” (140 mm) deep, using a 120 mm sleeve bearing fan on its bottom.

This power supply doesn’t have a modular cabling system, and only the main motherboard cable has a nylon sleeve, which doesn’t come from inside the unit. This power supply comes with the following cables:

  • Main motherboard cable with a 20/24-pin connector, 20.1” (51 cm) long
  • One cable with two ATX12V connectors that together form an EPS12V connector, 24.4” (62 cm) long
  • One cable with one six/eight-pin connector and one six-pin connector for video cards, 20.5” (52 cm) to the first connector, 5.9” (15 cm) between connectors
  • One cable with three SATA power connectors, 20.9” (53 cm) to the first connector, 5.9” (15 cm) between connectors
  • One cable with two SATA power connectors and one standard peripheral power connector, 20.9” (53 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, 20.5” (52 cm) to the first connector, 5.9” (15 cm) between connectors

All wires are 18 AWG, which is the minimum recommended gauge.

The cable configuration is adequate for a mainstream 500 W power supply.

Huntkey Win7 6600 power supplyFigure 3: Cables

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

[nextpage title=”A Look Inside the Huntkey Win7 6600″]

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.

Huntkey Win7 6600 power supplyFigure 4: Top view

Huntkey Win7 6600 power supplyFigure 5: Front quarter view

Huntkey Win7 6600 power supplyFigure 6: Rear quarter view

Huntkey Win7 6600 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 the transient filtering stage, this power supply is flawless, with two Y capacitors and one X capacitor more than the minimum required.

Huntkey Win7 6600 power supplyFigure 8: Transient filtering stage (part 1)

Huntkey Win7 6600 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 Huntkey Win7 6600.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the Huntkey Win7 6600. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses two T8KB80 rectifying bridges connected in parallel, attached to the same heatsink as the active PFC transistors and diode. Unfortunately, we couldn’t find the datasheet for these components, but it is clear that each bridge supports up to 8 A. So in theory, you would be able to pull up to 1,840 W from a 115 V power grid. Assuming 80% efficiency, the bridges would allow this unit to deliver up to 1,472 W without burning themselves out. Of course, we are only talking about these particular components. The real limit will depend on all the components combined in this power supply.

Huntkey Win7 6600 power supplyFigure 10: Rectifying bridges

The active PFC circuit uses two STP26NM60N MOSFETs, each one supporting up to 20 A at 25° C or 12.6 A at 100° C in continuous mode (note the difference temperature makes), or 80 A at 25° C in pulse mode. These transistors present a 165 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.

Huntkey Win7 6600 power supplyFigure 11: The active PFC diode and the active PFC transistors

The output of the active PFC circuit is filtered by one 330 µF x 450 V electrolytic capacitor from a company called TL, labeled at 85° C.

In the switching section, two STF13NM60N MOSFETs are employed using the traditional two-transistor forward configuration. Each transistor supports up to 11 A at 25° C or 6.93 A at 100° C in continuous mode, or up to 44 A at 25° C in pulse mode, with an RDS(on) of 360 mΩ.

Huntkey Win7 6600 power supplyFigure 12: Switching transistors

The primary is managed by the omnipresent CM6800 active PFC/PWM combo controller.

Huntkey Win7 6600 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 Huntkey Win7 6600 uses a regular design in its secondary, with Schottky rectifiers.

The maximum theoretical current that 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 four STPS30L60CT Schottky rectifiers, each one supporting up to 30 A (15 A per internal diode at 130° C with a 0.75 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 STPS30L30CT Schottky rectifiers, each one supporting up to 30 A (15 A per internal diode at 140° C with a 0.57 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 STPS2045CT Schottky rectifiers, each one supporting up to 20 A (10 A per internal diode at 155° C with a 0.84 V maximum voltage drop). This gives us a maximum theoretical current of 29 A or 143 W for the +3.3 V output.

Huntkey Win7 6600 power supplyFigure 14: One of the +5 V rectifiers, two of the +12 V rectifiers, and one of the +3.3 V rectifiers

This power supply uses a CG8513 monitoring integrated circuit, but this chip isn’t listed on its manufacturer website, so we can’t comment on the protections it supports. (We can assume that it supports over voltage and under voltage protections.) Additionally, the power supply uses an LM339 voltage comparator to expand the functionalities of the CG8513 integrated circuit.

Huntkey Win7 6600 power supplyFigure 15: Monitoring circuit

The electrolytic capacitors that filter the outputs are from Fcon 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.

Huntkey Win7 6600 power supplyFigure 16: Power supply label

According to the label, this unit has two +12 V rails. Inside the unit, even though the two +12 V “rails” use separate filtering components, they don’t have a current sensor (“shunt”), meaning that there is no individual over protection circuits monitoring them, a condition that is required for a power supply to have virtual +12 V rails. Therefore, this power supply in reality uses a single-rail design. Click here to understand more about this subject.

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 and +12VB inputs were connected to the single +12 V rail. (The EPS12V connector was installed on the +12VB input and the other connectors were installed on the +12VA input.)

Input Test 1 Test 2 Test 3 Test 4 Test 5
+12VA 3.5 A (42 W) 7 A (84 W) 10.5 A (126 W) 14 A (168 W) 18 A (216 W)
+12VB 3.5 A (42 W) 7 A (84 W) 10.5 A (126 W) 14 A (168 W) 17 A (204 W)
+5 V 1 A (5 W) 2 A (10 W) 4 A (20 W) 6 A (30 W) 9 A (45 W)
+3.3 V 1 A (3.3 W) 2 A (6.6 W) 4 A (13.2 W) 6 A (19.8 W) 9 A (29.7 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 102.4 W 208.4 W 294.8 W 395.6 W 503.3 W
% Max Load

20.5% 41.7% 59.0% 79.1% 100.7%
Room Temp. 46.0° C 44.2° C 43.9° C 44.7° C 44.4° C
PSU Temp. 45.9° C 45.9° C 45.8° C 46.4° C 46.6° C
Voltage Regulation Pass Pass Pass Pass Pass
Ripple and Noise Pass Pass Pass Pass Pass
AC Power 120.6 W 247.2 W 347.0 W 474.4 W 623.0 W
Efficiency 84.9% 84.3% 85.0% 83.4% 80.8%
AC Voltage 118.1 V 117.0 V 115.9 V 115.1 V 112.1 V
Power Factor 0.976 0.983 0.989 0.994 0.997
Final Result Pass Pass Pass Pass Pass

We had an interesting problem with the Huntkey Win7 6600: its protections are tightly configured. During our full load test, we had to increase the amount of current we were going to pull from the +12VA input from 17.5 A to 18 A, decrease the current on +12VB from 17.5 A to 17 A, and increase the current on +5 V and +3.3 V from 8 A to 9 A. If we tried to pull more from the +12 V outputs, the power supply would shut down. In fact, the power supply would shut down immediately if we tried to pull anything above 500 W from it.

Efficiency was between 80.8% and 85% during our tests. Therefore, this unit would be able to get the 80 Plus certification; however, the manufacturer chose not to.

Voltages were closer to their nominal values (3% regulation) during all tests, except the -12 V output during tests one and two, which was still inside the proper range at -11.42 V and -11.63 V, respectively. 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 Huntkey Win7 6600 provided  low ripple and noise levels.

Input Test 1 Test 2 Test 3 Test 4 Test 5
+12VA 23.6 mV 27.4 mV 30.4 mV 40.2 mV 50.4 mV
+12VB 23.2 mV 23.4 mV 25.6 mV 31.2 mV 38.8 mV
+5 V 16.6 mV 14.4 mV 16.0 mV 17.8 mV 20.8 mV
+3.3 V 6.4 mV 11.2 mV 9.2 mV 10.8 mV 12.8 mV
+5VSB 13.4 mV 12.4 mV 13.0 mV 15.0 mV 17.4 mV
-12 V 48.4 mV 41.2 mV 40.8 mV 46.0 mV 54.4 mV

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

Huntkey Win7 6600 power supplyFigure 17: +12VA input from load tester during test five at 503.3 W (50.4 mV)

Huntkey Win7 6600 power supplyFigure 18: +12VB input from load tester during test five at 503.3 W (38.8 mV)

Huntkey Win7 6600 power supplyFigure 19: +5V rail during test five at 503.3 W (20.8 mV)

Huntkey Win7 6600 power supplyFigure 20: +3.3 V rail during test five at 503.3 W (12.8 mV)

[nextpage title=”Main Specifications”]

The main specifications for the Huntkey Win7 6600 power supply include:

  • Standards: ATX12V 2.3
  • Nominal labeled power: 500 W
  • Measured maximum power: 503.3 W at 44.4° C
  • Labeled efficiency: NA
  • Measured efficiency: Between 80.8% and 85%, 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: One six-pin and one six/eight-pin connectors on one cable
  • SATA Power Connectors: Five on two cables
  • Peripheral Power Connectors: Four on two cables
  • Floppy Disk Drive Power Connectors: One
  • Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over current (OCP), and short-circuit (SCP) protections
  • Are the above protections really available? Yes
  • Warranty: NA
  • More Information: https://www.huntkeydiy.com
  • MSRP in the U.S.: NA

[nextpage title=”Conclusions”]

The Huntkey Win7 6600 proved to be a good mainstream power supply. It is nice to find a unit that always presents efficiency above 80%, yet the manufacturer has decided not to apply for the 80 Plus certification. Therefore, even though this power supply doesn’t have the 80 Plus certification, it consistently presents efficiency above 80 percent. Other highlights of this power supply include the excellent voltage regulation (three percent regulation for the positive outputs during all tests) and noise and ripple levels below half of the maximum allowed, which is what we like to see to consider a power supply “flawless” on this section.

The only issue with this power supply is its protections, which are tightly configured. We couldn’t pull more than 500 W from this unit. In fact, we couldn’t even use the same load pattern we usually use for testing 500 W power supplies. Some users will like to know that the protections of this power supply are in place. However, we prefer to see at least a 10% margin between the power supply labeled wattage and the maximum power we can really extract from the product. This would give us some margin for peak operation.

The Huntkey Win7 6600 accomplishes its goal of being a good mainstream power supply. Of course, if you want a power supply with higher efficiency, more cables and connectors, and some extra wattage between the unit’s labeled wattage and its protections’ trigger points, you will have to pick a different product.