Building Of A Psu Load Tester + update 7/4/2010

[hardnrg]

I got a 10MHz digital handheld scope for

[road-runner]

I agree - much better than throwing it in a rig and going "yep, it works!"

Just working and doing what it is supposed to is entirely two different things...

[Verran]

You can get USB and PCI digital scopes for around the same price, with the added bonus of the inherent ability of data logging, something my handheld scope can't do (the next model up has an RS-232 serial interface)

That's what I meant by PC-based really. An analog probe/readout setup would be great for just personal evaluation, but for any sort of formal reviewing, I'd think logging would be an integral part. Once you've got the log data, it'd be easy to throw a ripple algorithm at it and get some presentable data.

 

For $150ish, I'd think that's really not that bad for what you could do with it in a reviewing environment.

[anthony]

Thanks for all the support guys! I would definitely like to see OCC build one too, im sure you guys would put something amazing together. I looked into building a transistor based load, but that went right over my head

 

USB O scopes are in the mid hundred range, perhaps the most popular one is the Stingray, quite a number of jonnyguru people use it, along with other sites

 

Right now, progress is halted for a bit, waiting for my US based contact to forward me a package... takes customs avoidance to a whole new level

 

edit: sorry I missed a few questions! As for load, I tried to cut back on costs by eliminating the number of resistors, so for example, the 12V rail, ill be using two different rating of resistors, allowing either increments of 144W or 48W. I do understand this undermines flexability, but its what I can afford to put into the project right now. My original plans called for about 30 50W 4R resistors, allowing for some incredibly small increments, but that would be too costly. Eventually, I do intend to add more resistors allowing finer tuning

[Waco]

edit: sorry I missed a few questions! As for load, I tried to cut back on costs by eliminating the number of resistors, so for example, the 12V rail, ill be using two different rating of resistors, allowing either increments of 144W or 48W. I do understand this undermines flexability, but its what I can afford to put into the project right now. My original plans called for about 30 50W 4R resistors, allowing for some incredibly small increments, but that would be too costly. Eventually, I do intend to add more resistors allowing finer tuning

That makes sense. A 48 watt (4 amp) jump isn't really that bad anyway.

[anthony]

yeah thats what I reasoned, the 4A might be a bigger problem with lower wattage units, not that I expect to come accross too many of those, but, if I do, thats where I will have a problem (points at seasonic)

[anthony]

Update time !

 

Besides whats already been mounted, I got a few more resistors today!

 

couldnt be bothered to edit this one

 

Those enormous mofos in the center are 150W ones =O

 

Thermal paste supplied by Arctic Silver

[anthony]

Hello all Now that school is done, I can finally get back to working on this thing Ive got all the parts in, minus screws and wires, so I began to play with layout.

 

One thing I noticed is, not too many test their PSUs under heated conditions. So one of my goals here is to make a heatbox. Im still debating material... something easy to work with, heat resistant and insulates, to some degree.

 

Heres a rough run down

 

(BIG PICTURE)

 

Probably not at all clear, so Ill try my best to clarify. The majority of it will be the heat assembly, its really a two part thing, bottom shelf being the heater, and the top shelf being the box, which is not built yet =P

 

 

Alright, so not shown is the bottom mounted fan which brings cool air from the ground up through the heatsinks and out the top and into the heatbox. (Ill have pots for the top fan, and an exhaust for the heatbox to control temps, along with a thermometer)

 

For cooling the resistors, I have panelled off the back and front side to make somewhat of an enclosed area. On either side will an enormous AC fan pushing air right onto the heatsinks.

 

So here is where I am working on

 

1) [bottom right picture] best place to mount the small heatsink to not disrupt airflow

2) suggestions for material for the heat box?

 

more updates to come tomorrow/ the day after that, im going to start drilling =)

[anthony]

BIG, BIG, BIG update

 

 

Resistors mounted, heatsinks mounted, along with crappy psu for cooling fans

 

 

Nother angle

 

Whats missing from this pcture are the fans. intake/ exhaust at either end of the heatsink column, intake at the bottom, towards the middle of the heatsinks, and an exuast at the top near the far right side.

 

 

Heres an idea of how the two pieces will fit. The empty space on the right houses a plexi box for enclosing the unit being tested, where it will recycle heat produced by the resistors in order to simulate a stressed testing environment.

 

The emtpy space to the bottom left are for amp meters (eventually).

[Verran]

BIG, BIG, BIG update

I'll say! That's looking sweet man. Very professional looking :thumbs-up: .

[hardnrg]

yeah looks ace

[anthony]

=D thanks guys! I ordered a bunch of other things tonight, bunch of molex connectors, pins, fan grills, a duct + adaptors (for my heat box)... and Im going to waste a perfectly nice Silverstone SFF case

 

 

A big hole is going into this, and a duct!

 

To come: stingray usb scope, amp meters for each rail, and maybe some more resistors... im feeling 1kw isnt beefy enough!