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[nextpage title=”Introduction”]

HEC (a.k.a. Compucase) is a traditional OEM manufacturer, meaning that their core business is to manufacture power supplies (and cases) to other companies. They decided to enter the retail business but in order to not compete with their customers they decided to launch products with lower specs. According to HEC, their goal is to deliver high-quality power supplies costing less than high-end competitors. We’ve got a WinPower 480 W to see if this is really true. Let’s take an in-depth look at this power supply.

We would classify WinPower 480 W (WIN 480UB) as a mid-range product: it doesn’t have all the fancy features found on high-end power supplies, but at the same time it is far from being a low-end product, as we will see throughout this article.

In order to achieve HEC’s goal, this power supply doesn’t have active PFC and also doesn’t have a modular cabling system, like fancy high-end power supplies. Its design, however, resembles a high-end product. As you can see in Figure 1, it uses a big 120 mm fan on its bottom, using a mesh on the back. As you should already know, regular power supplies have only a 80 mm fan on its back. The solution used by HEC provides not only a far better airflow but also a lower noise level, as 120 mm fans are quieter than 80 mm parts.

Figure 1: HEC WinPower 480 W.

In Figure 1, you can see that this power supply has a 110/220 V switch, indicating that it doesn’t have PFC circuit (power supplies with active PFC don’t have a 110/220 V switch).

In Figure 2, you can see the power supply cables. Like we mentioned it doesn’t use a modular cabling system, however it uses a plastic sleeving on each cable in order to protect the wires and help the PC internal airflow.

Figure 2: HEC WinPower 480 W cables.

This power supply has six peripheral power cables: two Serial ATA power cables containing two SATA power connectors each; two peripheral power cables containing two standard peripheral power connectors and one floppy disk drive power connector each; one peripheral power cable containing two standard peripheral power connectors; and one PCI Express auxiliary power cable containing two auxiliary PCI Express power connectors for SLI or CrossFire configurations. This power supply also comes with an EPS12V adapter that can be installed on any standard peripheral power connector from the power supply.

[nextpage title=”Introduction (Cont’d)”]

High-end power supplies would use two separated auxiliary PCI Express power cables instead of using two connectors sharing the same cable (see Figure 3) and also they would use a separated cable for EPS12V connector instead of using an adapter (see Figure 4).

Figure 3: The two auxiliary PCI Express power connectors share the same cable.

Figure 4: EPS12V connector is provided through an adapter.

This power supply uses two main cables, the main motherboard cable with a 20/24-pin connector and an ATX12V cable. Like we explained, this power supply provides an EPS12V connector through an adapter.

Figure 5: Transforming its 24-pin power connector into a 20-pin one.

The gauge of the wires used on the main motherboard cable is 18 AWG, but all other wires are 20 AWG, which is thinner.

Only one aesthetic detail HEC could have worked on is regarding the plastic sleeving used by the cables. The sleeving doesn’t come from inside the power supply housing, so the wires are exposed when they come out of the power supply housing.

Figure 6: The wires are exposed when they come out of the power supply housing.

This power supply is really manufactured by HEC, as we could check by reading its UL number.

We decided to fully disassemble this power supply to take a look inside.

[nextpage title=”A Look Inside The WinPower 480 W”]

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 inside and to compare this power supply to others.

In this page, we will have an overall look, while in the next page we will discuss in details the quality and rating of the components used.

We can point out several differences between this power supply and a very low-end (a.k.a. “generic”) one: the construction quality of the printed circuit board (PCB); the use of more components on the transient filtering stage; the power rating of all components; the design; etcetera.

On Figures 7 and 8 you can have an overall look from inside this power supply.

Figure 7: Inside WinPower 480 W.

Figure 8: Inside WinPower 480 W.

[nextpage title=”Transient Filtering Stage”]

As we mentioned on other articles, 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 than that, usually removing the MOV, which is essential for cutting spikes coming from the power grid, and the first coil.

This power supply from HEC has more than the minimum recommended number of components for this stage. In addition to the above list, it uses one extra metalized polyester capacitor (X capacitor), see Figures 9 and 10.

Figure 9: Transient filtering stage (part 1).

Figure 10: Transient filtering stage (part 2).

A very interesting feature from this power supply is that its fuse is inside a fireproof rubber protection. So this protection will prevent the spark produced on the minute the fuse is blown from setting the power supply on fire.

In the next page we will have a more detailed discussion about the components used in the WinPower 480 W.

[nextpage title=”Primary Analysis”]

We were very curious to check what components were chosen for the power section of this power supply and also how they were set together, i.e., the design used. We were willing to see if the components could really deliver the power announced by HEC.

From all the specs provided on the databook of each component, we are more interested on the maximum continuous current parameter, given in ampères or amps for short. To find the maximum theoretical power capacity of the component in watts we need just to use the formula P = V x I, where P is power in watts, V is the voltage in volts and I is the current in ampères.

We also need to know under which temperature the component manufacturer measured the component maximum current (this piece of information is also found on the component databook). The higher the temperature, the lower current semiconductors can deliver. Currents given at temperatures lower than 50° C are no good, as temperatures below that don’t reflect the power supply real working conditions.

Keep in mind that this doesn’t mean that the power supply will deliver the maximum current rated for each component as the maximum power the power supply can deliver depends on other components used – like the transformer, coils, the PCB layout, the wire gauge and even the width of the printed circuit board traces – not only on the specs of the main components we are going to analyze.

For a better understanding of what we are talking here, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU806 rectifying bridge in its primary stage, which can deliver up to 8 A (rated at 100° C). No heatsink was used to cool down this component. This is more than adequate rating for a 480 W power supply. The reason why is that at 115 V this unit would be able to pull up to 920 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 736 W without burning this component. Of course we are only talking about this component and the real limit will depend on all other components from the power supply.

On the switching section two 2SK2749 power MOSFET transistors are used under a modified single-transistor forward configuration. Usually this configuration uses only one transistor, but on this power supply two transistors were connected in parallel in order to double the maximum current.

Each one has a maximum rated current of 21 A at 25° C in pulsating mode, which is the mode used, as the PWM circuit feeds these transistors with a square waveform, or 7 A at 25° C in continuous mode.

If you pay close attention in Figure 11 you will see a small copper plate between the transistors and the aluminum heatsink, put there to improve heat dissipation.

Figure 11: MOSFET transistors used on the primary.

[nextpage title=”Secondary Analysis”]

This power supply uses four Schottky rectifiers on its secondary.

The +12 V output is produced by two MBR20100CT Schottky rectifiers, which can deliver up to 20 A each (10 A per internal diode, measured at 133° C). The maximum theoretical current the +12 V 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 (which in this case is made by two 10 A diodes in parallel). Just as an exercise, we can assume a typical duty cycle of 30%. This would give us a maximum theoretical current of 29 A or 343 W for the +12 V output. The maximum current this line can really deliver will depend on other components, in particular the coil used.

The +5 V output is produced by one MBR6045PT Schottky rectifier, supporting up to 60 A (30 A per internal diode, measured at 125° C). The maximum theoretical current the +5 V 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 (which in this case is made by one 30 A diode). Just as an exercise, we can assume a typical duty cycle of 30%. This would give us a maximum theoretical current of 43 A or 214 W for the +5 V output. The maximum current this line can really deliver will depend on other components, in particular the coil used.

The +3.3 V output is produced by another MBR6045PT Schottky rectifier. Using the same math this output has a maximum theoretical current of 43 A or 141 W.

Even though the +5 V line and the +3.3 V line have separated rectifiers, they share the same transformer output. So the maximum current both lines can deliver will depend a lot on the transformer.

The problem here is that apparently this unit uses an outdated design. As you can see the +12 V output has a far lower current limit compared to the +5 V and +3.3 V outputs, a scenario that was typical several years ago. Nowadays PCs pull more current/power from +12 V and we want see a higher limit on this output.

On Figures 12 and 13 you can see the four power Schottky rectifiers used on the secondary section of this power supply. As you can see, a copper plate is used between the +5 V rectifier and the heatsink in order to provide a better heat dissipation.

Figure 12: Power rectifiers used on the secondary.

Figure 13: Power rectifiers used on the secondary.

This power supply uses Taiwanese electrolytic capacitors from Teapo and CapXon. The two big capacitors from the voltage doubler are rated 85° C while all other smaller capacitors are rated 105° C.

[nextpage title=”Power Distribution”]

In Figure 14, you can see WinPower 480 W label stating all its power specs.

Figure 14: Power supply label.

This unit has two +12 V rails, distributed like this:

• +12V1 (solid yellow wire): Main motherboard cable, peripheral power
  connectors, SATA power connectors and half ATX12V connector.
• +12V2 (yellow with blue stripe wire): Video card auxiliary power cable and half ATX12V connector.

From the previous page we came with some maximum theoretical numbers for the +12V output (343 W), +5 V (214 W) and +3.3 V (141 W).

As we mentioned earlier the maximum current/power each line can really deliver will depend on other components, especially the transformer, the coil, the wire gauge and even the width of the printed circuit board traces used.

For the +12 V output HEC stated 17 A for +12V1 and 16 A for +12V2. This would give a 204 W and 192 W, respectively, or 396 W.

For the + 5 V output HEC stated a 35 A maximum current, which translates to 175 W, while for the +3.3 V output the manufacturer stated a 30 A maximum current, or 99 W. On the label, however, HEC says that the combined power of +3.3 V and +5 V outputs is of 220 W (since they are connected to the same transformer output).

Unfortunately we don’t have the necessary equipment to make a true power supply review; we would need to create a real 480 W load to check if this power supply could deliver its labeled power or not.

[nextpage title=”Main Specifications”]

HEC WinPower 480 W power supply specs include:

• ATX12V 2.2
• Nominal labeled power: 480 W.
• Efficiency: 75%.
• Active PFC: No.
• Motherboard Connectors: One 20/24-pin connector, one ATX12V connector and one EPS12V connector (adapter to be installed on one peripheral power connector).
• Peripheral Connectors: two Serial ATA power cables containing two SATA power connectors each; two peripheral power cables containing two standard peripheral power connectors and one floppy disk drive power connector each; one peripheral power cable containing two standard peripheral power connectors; and one PCI Express auxiliary power cable containing two auxiliary PCI Express power connectors for SLI or CrossFire configurations.
• More Information: https://www.hecgroupusa.com
• Average price in the US*: USD 46.00

* Researched at Shopping.com on the day we published this First Look article.

[nextpage title=”Conclusions”]

This power supply is far from being a low-end unit. Its internal design and the components used make it more like a mid-range power supply targeted to users that want a good power supply but are not willing to buy a very expensive model.

The components used internally are really good – the transient filtering stage, for instance, has more components than the necessary. The only thing we missed to say that everything is perfect in this power supply is the fact that its electrolytic capacitors aren’t Japanese. But that would be too much for its price range.

Its price is REALLY impressive: costing only USD 50 in the US, this is the power supply with the best cost/benefit ratio we’ve seen to date.

If you don’t mind missing four features found only on high-end models – active PFC, 85% efficiency (this power supply is labeled as having 75% efficiency), Japanese capacitors and modular cabling system – this is the power supply you should buy. Period.

This is the perfect choice for users assembling a PC and willing to buy a good power supply but don’t want to spend a lot of money. With the money you will save you can add more features to your PC (more RAM memory, for instance).