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Angry_Games

Who is the best with power supplies?

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Load build finished!

 

Load fully wired here:

 

psuload04bo4.th.jpg

 

Connected to power supply here:

 

psuload05qe9.th.jpg

 

Connected the power supply up to maximum load and temperatures of load good. The cooling fans appear to be doing a good job. Can't say the same for the power supply though. The power supply is my Atrix 500T, stated maximum is 650W, actual load approx. 450W and it makes an awful noise. Sounds like a coil or transformer vibrating. Not a good start.

 

I will start my first review now that I have everything.

 

More news soon I hope.

 

Regards

 

Paul

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The finished piece looks impressive but did you use AS5 paste on all the resistors? :)

Classic symptoms of a stressed out cheap PSU, the coils squeek.

 

Nice job and I look forward to the review.

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Not wasting AS5 on this. Went through nearly 20 grams of the stuff. Used a cheaper industrial heatsink compound by Servisol.

 

Regards

 

Paul

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You know I wasn't being serious about the AS5? ;)

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LOL, I sure didn't.

Bit of British humor, eh?

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Sharp

 

I was going to offer to change the servisol stuff for AS5 as long as you supplied it!

 

Regards

 

Paul

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I now have everything I need to do my first power supply review but I feel it should be made clear that, initially at least, the reviews are written by "computer enthuiasts for computer enthuiasts".

 

My reviews will not cover everything as laid out in the ATX12V Version 2.2 specification but will cover the most important points and provide important information to assist in the decision on the purchase of the power supply under consideration. I do not and can never really have all the necessary test equipment to "properly" test a power supply (unless I win the lottery!) and I think this should be made clear. I have read several reviews on the internet, some good, some bad, and the vast majority give the impression that the review gives the definitive answer on whether the power supply is worth buying or not. Lets face it all power supplies on the market today will run a PC in one form or another trouble free for years. The information that needs to be provided, at least on this forum, is will a particular power supply be suitable to power what will on the whole be a high performance system requiring clean, stable power and usually lots of it.

 

I can only give advice and hopefully with the assistance of several other knowledgable members of DIY Street I think we can give advice, as good as, if not better than other similar sites. If a power supply clearly fails then thats what we write. If it basically passes with reservations then we pass on the information. If it's consider excellent, in our opinion, then thats what we say. Most important of all I think we should leave it up to the prospective buyer to read the review and, armed with advice/information we give them, let them make their own decision on whether to buy or not.

 

Before any reviews are posted I think it would be a good idea to inform the reader, in the first post possibly, exactly how the power supplies are being tested. To this end I will initially submit a description of the testing method and then my first power supply review to Praz (if thats OK Praz). He can then go over them, pass them round, etc., and let me know what he and "the management" thinks.

 

I have all the measurements etc., for my first review it just needs writing up. I mentioned earlier in the post that the power supply was the Atrix 500T and that it would possibly make a good example of what not to buy. Well it does! If OK I think it would make an excellent subject for the first review as it is a fine example of what not to buy and why.

 

Regards

 

Paul

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That's what we need to see. A real crappy PSU. Hard for users to appreciate well built supplies without a bad one to compare too.

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That's what we need to see. A real crappy PSU. Hard for users to appreciate well built supplies without a bad one to compare too.

 

Agreed 100%

 

Paul, outstanding work so far. Thank you.

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Please find listed below a brief outline of the tests I propose to do on the Atrix 500T power supply for my first review.

 

ATX POWER SUPPLY TESTING

 

Introduction

 

The main aim of the reviews will be to test the power supplies against the manufacturers quoted specification and the ATX12V V2.2 standard and from the results offer advice on the suitability of the power supply for enthusiast/high performance computers. I will mention at this stage that testing a power supply “properly” requires some specialised equipment costing several thousand pounds which unfortunately is outside the budget of DIY Street. Having said that I think we can, with the equipment available, put the power supply through some pretty rigorous tests which will adequately test the unit and provide enough valid information on which to base any recommendations. The series of test performed on the power supplies is listed below along with a detailed explanation of the methods. I would hope to expand on these tests in the future should the reviews prove successful.

 

Electrical Safety

 

Electrical safety is hardly ever given a thought in power supply reviews but I think it’s important. (It probably comes from my background as a medical equipment service engineer). If I am going to be testing any power supply it would at least be reassuring to know it can pass a basic electrical safety test. All ATX power supplies will have to conform to one electrical safety standard or another and the one that immediately springs to mind is EN 60950 (Safety Of Information Technology Equipment) which all power supplies will have to meet if sold in Europe and I think the USA. The basic requirements of the standard state the power supply must meet the following criteria:

 

• The resistance between the earth connection point at the AC inlet and the power supply casing should not exceed 0.1Ω. Because I will be testing the unit with a mains lead attached I will be looking for a resistance of no more than 0.2Ω at a test current of 10A from the earth pin on the AC supply plug to any point on the power supply casing.

• The insulation resistance between the live and neutral conductors connected together and earth must exceed a certain level when subjected to a high AC or DC test voltage. This test gets rather involved and all I am going to say here is that I will be looking for an insulation resistance of >2MΩ at 500VAC.

• The earth leakage or touch current which simply put is the current flowing down the earth conductor under normal operating conditions should not exceed 3.5mA. This is quite important because if due to some sort of fault condition the earth is disconnected whilst the live and neutral remain this current will flow through anybody touching the case.

 

I won’t go into much detail here and just give a pass/fail on the review. If the result in my opinion is a fail I will give a briefly explain why.

 

Physical Weight

 

Usually, but not always, the heavier a power supply the better quality it will be. A rather simplistic test you could say but if a power supply contains more components, heavier heat sinks, etc., you can get a good idea as to its build quality. This one will possibly become more evident as more power supplies are tested. We will see.

 

DC Output Load Regulation

 

Custom Built Load

 

+3V3 @ 3.3A, 9.7A or 16.5A

+5V0 @ 5.0A, 10.6A or 17.5A

+12V0(1) @ 2.5A, 8.5A or 12A

+12V0(2) @ 2.5A, 8.5A or 12A

+12V0(3) @ 2.5A, 8.5A or 12A

+12V0(4) @ 2.5A, 8.5A or 12A

-12V0 @ 0.4A (Fixed)

+5VSB @ 2.3A (Fixed)

 

To try and simulate real world operation the power supply under test will be connected to the custom built load and subjected to a moderately heavy load for a burn in time of four hours. The output voltages will then be measured and checked against the limits given in the ATX12V standard. A simple pass/fail will be given for each rail.

 

Efficiency and Power Factor

 

The power supply under test will be connected to the custom built load and subjected to a low, medium and heavy load. The mains input power and power factor will be measured and recorded using the Prodigit 2000MU power meter. The DC output voltages and currents will be checked and recorded from which the total DC output power will be calculated and the efficiency and power factor given for each load level. The results will be checked against the limits given in the ATX12V standard. A simple pass/fail will be given at each load level.

 

AC Ripple On DC Outputs

 

The maximum level of AC ripple and noise will be checked while the power supply under test is loaded to its maximum level using an oscilloscope. The highest levels of noise are likely to occur at the mains input frequency and power supply switching frequency so particular attention will be paid to the levels at these frequencies. (At 50Hz and >20kHz). The results will be checked against the limits given in the ATX12V standard. A simple pass /fail will be given for each DC output rail.

 

Temperature, Fan Speed And Noise Levels.

 

These will, at the moment, be relatively simple tests but they will give a reasonably good idea of what to expect. The temperature will be measured using a type K thermocouple placed at the air outlet grill, kept in the same position at all stages, and the temperature of the air leaving the power supply recorded at low, medium and high loads. The fan speed however will be more accurate as I will be using an optical tachometer which will require the placement of a piece of reflective tape on one of the fan blades. The speed of the fan will then be measured, once stabilised, at low medium and high loads. Noise level will unfortunately depend on my judgement and I appreciate that what I may feel is quiet could to somebody else be noisy but for the moment this will have to do. (I may at some time in the future be able to get my hands on a sound level meter). There isn’t really any standard I can compare to in ATX12V so I will not be giving a pass/fail result in this section. It will be up to the reader to make their own judgement.

 

I think that will be all for now but as I said previously if the reviews prove successful I have ideas in mind for future improvements.

 

I thought a posting in this section would be best as only the VIPs can see it at the moment. Please read it and let me know what you really think. I won't be offended by any constructive comment or criticism. If I am going to do it I would like it done right!

 

Regards

 

Paul

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Paul,

 

I'm no power supply genius by any means, so I'll let Praz chime in with all the technical stuff. But from a layman's point of view, your testing methodology appears very solid.

 

Great stuff so far.

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Any chance of a bit more feedback please!;)

 

Back to Call Of Duty 4 for a while I think.

 

Regards

 

Paul

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