[ebswift]

This is informational/for info if anyone wants to copy what I am using here. I have a replacement MRS module in the mail and this has alerted me to the fact that if I need to code it I also need a PSU. So, I made one today, it hasn't yet been used in anger, but at least some initial testing has been done and it might be of some interest. The unit I chose is an ATSN 7001044, I also have a couple of DPS-700EB units on the way that are a little bit better tested in the community though don't have the amps of the 1000W unit (though research shows that may not be a big deal). I have 240V here in AU so get the full current output capability of the supply assuming it is going to work as expected.

First up, there is some conflicting info around setting the voltage output of the ATSN 7001044, as well as overriding overvoltage protection. These are two things I might have solved (I'm certainly not the pioneer here but couldn't find many decent references, especially in one place...).

Firstly, the basic blade wiring, this is pretty well documented, though for reference I used a 15K resistor to get the 12V output up to 13.67V as well as the other recommended hookup wires (initially I used 1K5 as per a set of instructions I found and the unit briefly output over 18V before I killed the power which wasn't good, but it doesn't seem to have destroyed the unit):

Top:


Bottom:


Next, disable OVP, otherwise the unit will not power on https://www.rcgroups.com/forums/show...&postcount=235

This is the jumper I installed, not overly easy, but where there's a will there's a way:



Power on result (no more power cutout after switching on):


For the heavy leads I used 140A leads:


Now for testing, clamped the positive lead:


The load, some coiled up wire submerged in water:


Measured load, this is 52 Amps:


Recorded voltage under load:


This load was rated to 52A, so the supply wasn't pushed to the limit, and the test was only run for a few minutes due to time limitations. It held voltage over that time, and dropped amps probably due to the load warming up, increasing resistance. In a few days, that's the next test, up the load and then let it sit for a while to see how it goes.

This was just the test setup. To polish everything off I have a nice Anderson connector in the mail and I'll rig something up (maybe 3D print) to hold everything solidly in place. As mentioned, I didn't invent this idea, but I haven't seen an end-to-end solution for getting these particular units working for our purposes, hopefully it is useful.

[ebswift]

Okay, the day arrived where I could do a decent load test. This time I pushed it up to 70A.



I ran the test for 1 hour and 20 minutes, the water got to 91 degrees C pulling up to about 930 watts at the start (dropping to about 830 I think it was later as the load heated up):



The fan speed steadily increased at the start and then levelled out, just whirring away steady. The PSU also got gradually warmer but evened out after about 5 minutes and didn't get any hotter. Touching the sides it felt like maybe 35-40 degrees C, I didn't have the thermal imaging gun handy unfortunately.

The load steadily dropped and evened out at about 62A:



The connections on the load test were not very good which contributed to the losses (this should not happen on the car):



Voltage dropped to a minimum of 13.5V at the terminals to the load. The terminal leads got lukewarm, I'd say no more than 30 degrees C. So this PSU seems rock solid, I now regret buying the two extra DPS-700EB units because these ATSN 7001044 PSU's push out a fair bit more power so likely won't work as hard in the biggest load scenario powering the car. I'll probably try it this weekend when I replace the MRS module (rain permitting), it may not be overly necessary but is good insurance anyhow.

[gamesfrager]

Your images are not showing. You need to share them from your google drive/photos.

[ebswift]

Originally Posted by gamesfrager

Your images are not showing. You need to share them from your google drive/photos.

Ah, I was blissfully unaware, they all showed up for me. I have fixed them now and tested in a guest window. Thanks for the heads-up!

[mp-E46]

Nicely done.
How is the ATSN 7001044 holding up? I need to get a PSU for coding and such. Would be nice if it can be fitted in a case or such to protect it.

[Sensible_]

Nice project!

[CarAbuser]

Interested in doing this. How would a PSU like this compare to one of those Schumacher INC-700A?

I can pick up a ATSN 7001044 for £20 on eBay. Seems like a crazy bargain when all that's needed is a bit of soldering.

[mp-E46]

ebswift - Any update you can share with us? Thanks

[ebswift]

Originally Posted by mp-E46

ebswift - Any update you can share with us? Thanks

Oops, I got side tracked for a bit

Anyway, my MRS didn't need coding, I actually went through a couple before the last one stuck, I learned as long as you match the part number you are good. My '06 320D is still going after a few common repairs but has been beaten to death by hail and the clear coat has pretty much failed. Still a very nice driver...

Anyway, back on topic, I added the Anderson plug and added a power meter sourced from banggood:

https://www.banggood.com/100A-DC-Dig...p-1087119.html

The shunt resistor is connected inline on the negative supply where you see the heat shrink:





It all looks nice and seems to work great but I haven't needed to use it .

Anyway, I hope this wraps up where this build ended up.