.:!Work Log!:. PSU Load Tester Build (XATE-984)

[mpilchfamily]

XCPU's XATE-984 Load Tester (Build).
Latest image: All done except for some possible future mods.


The time has finally come. After about 4 months of planning and finally securing funding and resources for the build it has come time to start the work log. You can find the development and planning for the build at the following threads.

Building a PSU Dummy Load/ Test Bed
Designing a PSU load tester.
PSU Load Tester Design 4

The design went threw many changes and revisions. All in an effort to stream line the design and keep the total cost down. In the end the total cost is just over $700. This may have been much higher if it hadn't been for donations of wire and the 2 large heat sinks made by kwalker and blunc. Also a big thanks to brentpresley for the $700 in funding for the build.

So last night i received the case for the build as well as the connectors for it. Of course i had to jump right into prepping the case. Al many of you know from keeping track of the design stage of the build i have already built the cooling cannon that will hold and cool all the resistors.

Well the first thing i did was to strip down the case and see where everything needs to go. luckily there are only 10 rivets on the entire case. Every thing else on the case is held together with screws. This made the strip down allot easier. So first I'll offer what it looks like before i stripped it down.
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Then i try to get a feel for where the PSU and cooling cannon need to go.


After that i start trying to figure out what I'm replacing the back panel of the case with. So i take a piece of mesh that i salvaged from an old IBM server to see if it will fit.


Looks pretty good but was a bit short on the sides. Luckily all i had to do was flatten out the side and it was more then long enough to fill the hole where the I/O shield and PCI slots where. So after a bit of cutting with my tin snips and drilling holes for rivets i had the back covered.


After some more test fitting of the items i decided it was best to strip the PSU out of its case and mount it directly to the motherboard tray. I had to take the 80mm fan in the PSU and mount it on top of the PSU's heat sink to ensure proper cooling of the unit.


The PSU is a bit of a permanent fixture in the case so i wanted it to look like part of the case. So the connector for the power cord was mounted to the mesh. I also took the 120mm fan that came in the front of the case and moved it to the back.


To finish off the nights work i re aligned the Cooling Cannon to work around the PSU and leave plenty of room around it for running wires.


I'm still undecided about weather I'll ad a window mod to the top of the case with the XCPUs logo. But it is something i can work on as i wait for the other parts to arrive. Most of them should be here later today. Then i can start figuring out the layout of all the switches and meters on the front panel. I suspect I'll have a bit of cutting to do on the front to accommodate the panels and switches.

There will be allot of wires running threw this thing. I almost dread the wiring I'll have to do on this thing. I'll be updating the work log as often as i can. It all depends on when i can get a chance to work on the system.

[MagicLess]

Nice work on this.

Can't wait to see the finished look, but then again, I bet you're a hundred times more excited.

[mpilchfamily]

You bet i am. And I'm just getting started.

I received the temp monitors this morning and I'm expecting the order from Mouser.com to come in tonight. They where nice enough to upgrade my shipping to 2 day air for free. In that shipment is one of the switches for the panel meters, the panel meters, shunt resistors and terminal blocks. Once that arrives i can begin arranging how everything will be mounted to the front of the case.

Here you can see the front of the case and the front opened. Much of the panel behind the front face will be removed to make way for the switches and meters.



Now that i have the temp monitors it seams the slots in the front are going to be a problem.

They where smaller then expected. There size is such that cutting a hole to mount them in isn't possible. The slots all line up just right so that the hole will always be too big.


So I'll be forced to get a sheet of black anodized aluminum and completely modify the front face. I'll cut out all the slots and rivet the aluminum panel in its place. I think the slot spacing would have presented a problem for the switches as well.

That about covers it for now. We'll see what else comes up as i get more parts in. I still haven't heard back from Radio Shack yet so i don't know if/when the parts shipped. But all the other switches and the solder are coming from the Shack. I also have to put in the last order from Mouser.com and get all the Resistors shipped. Then the real fun begins. I've already got my wire all set up and ready to go when everything gets here.

[huddy]

Looks like a good start!

[mpilchfamily]

Time for another update.

While waiting for the next shipment of parts to arrive i went about working on the PSU connectors. Mainly it was converting the 2 extra 24 pin connectors i ordered into the 4 PCI-e connectors i needed.

After some hacking i had 3 connectors from a single 24 pin connector.


In preparation for the terminal blocks and shunts arriving i removed the front face of the case.


The case is a bit flimsy so i took the drive cages and mounted them back into the case. Now because the HDD cage got in the way i had to modify it a bit but in the end it all worked out great.



Well not long after that a knock came and the door. It was my friendly neighborhood UPS guy. My package from Mouser.com has arrived minus a switch that is on back order. But now i have the Shunts, terminal blocks and the panel meters. I was surprised at how small the meters where and how large the terminal blocks are.


With all of this now in hand i went about mounting the Shunts into the 5.25" bays and wiring the connectors to it. I also mounted the shunts there and got them wired in as well.



All the +12v wires are on one terminal block and the ground wires are on there own block. All other wires are wired into a third terminal block. As you can see in the pictures the +12V wires are split so each of the +12V rails takes 3 of the terminal. Then each group of 3 is jumpered together and then wired to there own shunt. The 3.3V and 5V rails each have there own shunt. Then the 2 +12V shunts will be wired to the back ordered switch so i can toggle from one to the other to get the amperage reading from those rails.


The other large terminal of the shunts will be wired to the switches. Still waiting for Radio Shack to send those. I'm amazed at the progress I've already made. But there is still so much more to do.

By tomorrow the rest of the money for the build will be in the account. So I'll be ordering a sheet of black anodized aluminum sheet from FrozenCPU. Then i can start working on the front face of the system and prepping it for the switches and meters.

My finger tips are sore from all the stripping and twisting of the wires. And there is allot of that in the weeks to come. Every bit of the ground wire will be stripped of its isolation. I'm not really sure if I've got thick enough wire. I may have to double up on the 12GA. If that is the case then every bit of wire needs to be stripped.

[Lionhardt]

Wow, this is a great job you're doing. You must have some insane dexterity for some of this stuff. Keep up the nice work.

[SirRobin4ever]

Wow Mpilch.....this thing is VERY impressive. Then again, with the amount of planning put into it, it should be!

Looking forward to seeing some results with this thing.

Oh, and I especially like the reuse of the old Coolermaster blower fan.

[Tark]

its nice to finally see something physical after all the months of planning. *thinks of mplich like a giddy child at this point*

[mpilchfamily]

Thanks

Its been a tight fit getting in there to tighten the screws on the terminal block. Things will be tighter as i start to wire everything.

I've spent the last 2 hours working to make a good templet for the meters.


Took allot of nibbling and filing. The templet for the temp meter is a bit big but thats OK. After tracing the templet out on the front of the case it will be a bit smaller. So it will all work out.

I also finally got word that the shipment from radio shack with all the switches and solder have been sent today.

[Lionhardt]

Its been a tight fit getting in there

That's what she said.

[Farhang]

You rock Thunder God!

[Blunc]

Wow, that is a tremendous amount of work. You da man!

I would suggest (if you have the time, and for future rework/repair purposes) that you label the shunts and major assembly points(as to which circuit they are in). Someday in the distant future when some part can't hold up you may want some easy reference points on your parts to speed your repairs.

I look forward to seeing how the concept of the "heatsink cannon" works.

[mpilchfamily]

Its all pretty easy to tell what is what since the cables going into the terminal blocks are color coded according to there voltage. The positive voltages are on the side terminals and the ground is at the bottom. The connectors are all labeled so that i know which 12V bank they go to. When the resistors arrive some time in the next week or 2 they will be mounted to the cooling cannon. The +12V1 resistors will be on top and the +12V2 on the bottom. The 3.3V will be on one side and the 5V on the other. The 5VSB resistor will be on the side with the +5V and the -12V resistor will be on the 3.3V side. This week I'll be sorting out the cables from the system's PSU. I'll also be adjusting the PSU so that i can fit a second 120mm fan in the back just behind the PSU. Other then that there isn't much else i can do till more parts arrive. I hope to have the switches and solder before the end of the week. This will allow me to lay out where everything on the front panel will go. Then i can cut the venting out of the front panel and place a new aluminum plate in its place. I plan to have the plate mounted on to with some spacers used to allow intake air to enter around the front panel.

My schedule has just changed as of today. I've been asked to take up a leadership position in my churches Boy Scout troop. So Thursday nights will be Scout night for me. Thursday is one of my off days and was one of the days I'd use to work on this project. But i don't see it getting in the way much.

[mpilchfamily]

Well i have some bad news here. As much as i would like the completion date to be the end of this month it may be 3 or 4 months till the system is completed.

According to Mouser there are 4 resistors on backorder. This i already knew. What i just found out however is that 3 of them will not be shipped till March. To be exact one ships on or about the 17 and the other on or about the 31. So this is a bit of a set back. I also know that the switch needed to have one of the panel meters switch form 1 12V bank to the other is on backorder but i have no idea on its arrival time.

Lets see the resistors that are missing are:

• 1X 1.65 Ohm for the 3.3V bank, ETA- unknown
• 2X 3 Ohm one for each 12V bank, ETA- 3/31/08
• 1X 2.5 Ohm for the 5V bank, ETA- 3/17/08

So that is the 4A load on the 12V banks, 2A on the 3.3V bank and the 2A on the 5V bank. This limits the ability of the load tester but it will still be operational. Except for the inability to have an curate amperage reading from the +12V banks. That alone is the largest setback so far. Till i can get that switch or another DPDT switch that can handle about 50A the Load Tester is just going to be sitting here. Time will tell.

This kind of thing happens when you have a large array of parts involved.

[SirRobin4ever]

Sorry to hear that Mpilch. Hope you can find another vendor or luck is with you, and the parts show up early!

[mpilchfamily]

Well there is more then enough to do in the mean time. Like i said the switch is the real thing holding me back. The resistors can always be added later and can be worked around for now what reviewing. But reviews will only start once i have all the equipment. Meaning i still need an O-scope. Mouser may have other Resistor of the same spec in stock but the manufacture of those charge more. Money is already tight as is.

But earlier today i went to Home Depot to pick up some miscellaneous items. I needed to get a couple more bolts for supporting the Cooling Cannon. I just finished up a new addition to the case. After adding the new retaining nuts to the cooling cannon supports i moved the PSU forward a bit so that i could add a second fan. Because of clearance issues, and the fact that i didn't want to break out the Dremel and hack up the back end of the motherboard trey, i had to mount the fans ****eyed. Other wise I'd only be able to used the bottom of the fans to screw them into place.

The fan on the right is the one that came with the case and the one on the left came out of a cheap $20 PSU.


As you can also see I've taken out the Cooling cannon for now. I also went around and put a dab of hot glue around the nuts on the cooling cannon mount so they won't get spun out of there position.

I expect the switches to show up this week as well as the aluminum panel for the front face. Then I'll be able to work out the position of everything on the front of the system.

If anyone can find me a DPDT switch that can handle no less then 41A then let me know.

[unholy]

If anyone can find me a DPDT switch that can handle no less then 41A then let me know.

What you need there is a circuit breaker. Otherwise u want to use a Horn Relay (they go upto about 100A ratings i believe, generally SPDT though but u can always hook it up to make two a single DPDT )

Coming along nicely, i like those small shunts .

[mpilchfamily]

Well the switch i have ordered is only $7. I really don't have much more then that to spend on it. But if i have to go with 2 SPDT switches then so be it but I'd rather keep it at one switch. I'm afraid things are going to be a bit crowded on the front face of this thing. So i might have the panel meters, there switches and the temp monitors on a separate stand of some sort that plug into the front of the system. We'll see what happens there. I'll be exploring my options more while I'm at work tonight.

[mpilchfamily]

Well according to Mouser they have 4 of the switches on order. I clicked on the link they offer for viewing delivery date and it said 12/12/2012.

I'm online with a rep from Mouser now trying to find out when i might get my hands on the switch. Like i said the Resistors can wait a while. Well it seams they have not gotten an estimated ship date from the manufacture on that item. A new option will be found in the mean time.

[mpilchfamily]

Can someone tell me if a switch is rated at 50A @ 125VAC will work with 50A @ 12VDC?

I'm starting to think my best cource of action will be an old school aproche. Use a single panel meter and set it up like an old style telephone switch board. Have 2 connectors coming from the panel meter to the outside of the case. Then plug the connectors into the apropriout test point on the front to get my reading. At least then i could return one of the panel meters and the other DPDT switch. I think banana jacks will do the trick. As a temporary fix till the switch arives i can put the second meter in a project box. In the place of where the second panel meter will eventually go i'll have a molex connecto there to plug into the panel meter for power. The Bnanna terminals will be mounted to the back of the project box so i can plug the meter into the 2 different teast points for the 12V banks of resistors. But that means useing dual test points on the 12V banks. One test point for either side of the shunt resistor. Wires hanging out of the mounting hole i guess. I think i can work around the back order parts without any problem.