2022 ITTSB Project: Triple Rail DC dummy load 330W for ATX PSU testing

[Kiriakos GR]

Since the year of 2003 it was in my plans to make one dedicated ATX PSU load tester.
Back then, market was full of 350W PSU, and 10% load testing it was enough as quick test.

By accepting at 7/2022 thee PSU from Seasonic for me to review, the idea of Triple Rail DC dummy load this awaken again.

New problems on this equation:
a) The average ATX PSU this grown from 350W (2003) to 750W
b) Spesific timing for DIY projects making, this is the worst ever:
1) All European citizens are now in fear of highest ever prices for natural gas and electric energy.
2) Pricing of parts for DIY projects won in a day 50% of higher cost in Greece (September 2022).
3) Business activity half frozen, and I am also feel scared and unable to predict the future.

The new solution: 
To go ahead and make my new Triple Rail DC dummy load tester, by the use of salvaged parts that I do all ready own, plus few new parts that they are required.

The new PSU Tester exterior design this started in simulation, by me using the Corel-Draw software.   
Within several hours I did succeed to complete the design of face-plate. 

Metal case for this project: UPS MGE Pulsar ESV 22+
Height: 240mm
Width:  170mm
Length:  430mm

One picture 1000 words, but I will demonstrate shortly detailed pictures of all parts. 

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Triple Rail DC dummy load 330W for ATX PSU tester features:

a) 5V, 3.3V, 12V: Load test at 10% & 50%  (according to 80PLUS testing process) for 750W.
b) 12v Rail five step loading at increments of 4.5A (22A max)
c) Actively cooled
d) cement resistors 5% 15 Watt
e) H4 12V 60/55W 
f) Banana plugs / DC voltage monitor 
g) BNC Plugs /  AC Ripple  (oscilloscope input)

Notes:
a) immune to magic smoke. 
b) Signed reliability by Kiriakos Triantafillou - Real electrician ! 

 

[Andrew-88]

Over the years Kiriakos did proved his talent as iron-man 
Extreme demonstration of high-end craftsmanship when he is dealing with all sort of metals.

Past made VARIAC project this had 5.5mm thickens of aluminum face plate, which Kiriakos successfully deal with it !!
http://www.ittsb.eu/forum/index.php?topic=1240.0

This new project it does have a first significant challenge, all parts at face-plate, they should be installed with extreme caution to detail regarding precision placing next to its other.
I am looking forwards to see all steps of upcoming progress of it, with great interest. 

In our times they are not many hero, which they do deliver high-end craftsmanship just by the use of their bare hands.   

[Kiriakos GR]

Best advice prior any one starting any high-end craftsmanship project = have a real good night sleep first 

[overvolt]

New adventure ahead ! 
This metal case seems huge, and has good design speaking of potentials for active ventilation.
I will get in the line too, so to watch the rest of the progress.  

[Kiriakos GR]

Mix of new and used parts in my ownership, so to retain total costs at minimum

Beginning of September project parts price gained 50% increase = 2.5 ~3.0 EUR per a single toggle switch.   

I am not planing to deliver any electrical schematic about this project, I am not that generous these days.
Especially when this year, Blog donations fall down to zero.

Below are detailed pictures of my part list, so my readers to use as inspiration.
 

[Andrew-88]

Now I have good clues of where the huge heatsink of welder, this will be used at. 
(Post #1)

[overvolt]

Mix of new and used parts in my ownership, so to retain total costs at minimum

My quick costs pricing estimate, by also including the wiring costs, this is close to 90 EUR, and if you get a new project box? this is plus 50E.
Sum could be 170E ~ 190E including several DC fan.
Just my note for the ones who might think to replicate it.     

[Kiriakos GR]

I will give detailed sum of costs at the project end.
Parts plus portion of electric energy used 

Today's work = progress
a) Metal sheet (front-face) this were cut internally, and now it become a frame with 12mm surround wall, for the addition of screws.
b) Aluminum sheet this were cut accordingly.
c) First aluminum sheet this is 1mm of thickness = soft, and I was forced to cut and a second and identical one, and to add both as one = sum of 2mm of thickness.
d) Both aluminum sheet were centered - drilled - bolted.
e)  Sum of work hours = around five  (for retention of accurate made work at its step.

   

[Kiriakos GR]

Today's work = progress

a) Construction of accurate paper model of panel meter dimensions.
b) Accurate positioning of top side parts.
c) Accurate slow motion cutting of ammeter hole.
d) Marking and drilling of power switch holes, all in perfect alignment.

 

[Kiriakos GR]

Skipped one day and now I am moving on.
Working with aluminum this requires of you to have other than skills and a good and mistake-less strategy = systematic work.

Plan, drill, clean all particles, REPEAT
Plan, drill, clean all particles, REPEAT

This is a taste of after drill period 

[Kiriakos GR]

This thing started looking as planed !! 
Plus four work hours up to this point. 

[Kiriakos GR]

Today's work = progress (Sunday)

a) The aluminum face plate, this is now 99% ready.
The aluminum were cleaned, all major parts are now installed.
b) All wiring for measuring points, three multimeter along three BNC for Oscilloscope connections, all are in place, tested and ready.
c) Power on switch (remote control) with 5 VSB voltmeter, in place and functional.

To do:
a) wiring up to load control switches
b) ammeters wiring
c) dummy load three circuits
d) installation of PCI-E and CPU (add-on cables harness)  at the front plate as it was planned.

By me completing the construction of the front plate, due 100% of mistake-less work, 80% of my own worries or personal fears they are now vanished. 
There is still work to be made, but I feel now other than very tired also very confident, about the final mission success.   

(My digital camera, Olympus C2100, this has high sensitivity at the frequencies Ultraviolet and the colors of blue LED they look as burned)