ET5410 Electronic Load mod: add external sense

[cybermaus]

I have made a small mod for the (too loud) fan.
I use a lot 40°C Thermal Switch (Normally Open) for many devices which have too loud fan (I don't know the real name of this component).

Hmm, that is not a bad idea. Simple enough.
It's just called a thermostat. Probably this model uses a simple bi-metal switch.
Next time I order some stuff I should have some come along.

Can I suggest to you that you put some sort of isolation on the scews for the heat-sinc stands?
They are connected to the Red (+) terminal. One small dent in the side, and you are shorting the latter to ground.
I just put some felt pads between the screws and the sides. It not only isolates, but also helps prevent dents and reduce vibrations.

[ceut]

I have made a small mod for the (too loud) fan.
I use a lot 40°C Thermal Switch (Normally Open) for many devices which have too loud fan (I don't know the real name of this component).

Hmm, that is not a bad idea. Simple enough.
It's just called a thermostat. Probably this model uses a simple bi-metal switch.
Next time I order some stuff I should have some come along.

Can I suggest to you that you put some sort of isolation on the scews for the heat-sinc stands?
They are connected to the Red (+) terminal. One small dent in the side, and you are shorting the latter to ground.
I just put some felt pads between the screws and the sides. It not only isolates, but also helps prevent dents and reduce vibrations.

Hello,
Thank you for your great advice !
I have teardowned again my ET5410 because I have received an Arctic F8 fan (airflow=31CFM), to try it inside.

And you are totally right ! The (+) is on the heatsink 
In fact, it is because there are no thermal isolation pad between the mosfet tabs and the heatsink (maybe the heatsink is a part of the current sinking :-? )
So I have put 2 pieces of ductape on each of the 2 opposites screws.

For the F8 Fan: it is a failure  the airflow is too low 

I have checked all good PC fan brands (Noctua, Arctic, Coolermaster, Antec, bequiet and other brand) and I can't find any that matches the one inside (I have looked for a 0.35A / 4.2W fan at 4000rpm).
I have ordered a little UT363 to check the airflow, but I'm stuck.

Mine has an horrible metallic noise when it's rotating: I think there is a bad ballbearing inside.
Fortunately the "thermostat" saves me    (it is a simple bi-metal switch as you say=>there is a very little "clic" like a relay when it is activating)

If someone has an idea to replace the 80mm fan inside ?


Edit: I have ordered a Arctic "P8" version: it is the high static pressure version, to try it...

[vav]

Hi, I'm the new owner and I made some adjustments. I placed the
1.USB port on the front panel
2. I added terminals for 4W measurement
3. I added a 2W / 4W switch
English is not my native language, I use a translator.

[cybermaus]

Hi, I'm the new owner and I made some adjustments. I placed the
1.USB port on the front panel
2. I added terminals for 4W measurement
3. I added a 2W / 4W switch
English is not my native language, I use a translator.

looks nice.

[T3TRIS]

Well, I'm reviving this one, hopefully!
I bought an East Tester ET5410A+ DC load and have been using it for testing LiFePO4 battery builds. It has worked fine so far and has been useful for capacity tests. However, one of these capacity tests is pointing to an issue with battery I made, and I now want to test individual cells. The issue that brings me here is the voltage sense wires. They aren't critical for an assembled battery with BMS but for single cell tests, it's a pain. I had started a 40A load test on one cell, telling the load to stop at 2.5V. However I quickly noticed the 0.5V voltage drop between the cell terminal and the load (using 6AWG cables and crimped lugs).
Anyhow, I now want to do this voltage sense wire mod, but apparently the A+ version of the ET5410 doesn't look friendly to that!

I can solder some wires to banana plugs, but to be honest, finding where to solder on this board seems to be above my pay grade.

Has anyone ever figured this one out?

I also sent an email to East Tester directly to see if they can assist.

Thanks

[Hotcooler]

Has anyone ever figured this one out?

I also sent an email to East Tester directly to see if they can assist.

Did you get any reply? In theory there is a compenstation function that seem to work on videos, have you tried it?

[T3TRIS]

Oh I have not!! I didn’t know this was a thing (didn’t see a video). What I’ve done so far is use oversized wires and decrease the amperage toward the end of the test, which reduces the voltage drop. I’ll have to find that video, thanks!

[Hotcooler]

Oh I have not!! I didn’t know this was a thing (didn’t see a video). What I’ve done so far is use oversized wires and decrease the amperage toward the end of the test, which reduces the voltage drop. I’ll have to find that video, thanks!

Here you go : https://youtu.be/pT5kuc2fNRQ?t=1778

I have one on order, since it was.. very attractively priced compared to the older version or even the DL24E in a resonable setup, so yet to test that myself.

[T3TRIS]

Here you go : https://youtu.be/pT5kuc2fNRQ?t=1778

I have one on order, since it was.. very attractively priced compared to the older version or even the DL24E in a resonable setup, so yet to test that myself.

So simple! Thank you for sharing. I’ll test it when I get back home.

[kawal]

Post some more pictures of the board with focus on the area close to the metal bars.  Shine a light behind the board to  see the traces. Most likely the voltage measurement is in the area of the op amps close to the metal bars.  There are probably some tiny traces going away from the bars area to measure voltage. 

[kawal]

Anyone want to do the remote on ET5410+ this is how:

Cut traces going to the terminal
Solder wires to resistor pads as shown . Other side will be your sense connections.

[mawyatt]

If these are cut/opened don't you run the risk of having unknown voltage sensing without the sense cables connected?

Would think a safer approach would be to add some series R of equal value, maybe 1K, in each leg where you would have the opens, then wire the sense terminals as you've shown. If the sense cables aren't attached or fall off you still have voltage feedback, and if the sense cables are utilized they short out the 1K added resistors to compensate for the load current carrying cables.

Anyway, just some thoughts.

Best,

[andyB2022]

How I would do it, First cut the traces mentioned by kawal, now we have an open middle point (the place we cut) from the lef of the cut run 2 wires to the middle conection of a DPDT switch, then from one of the switch positons run wires back to the side going to the resistors (right of the cut) and another pair of wires (using the last contacts on the switch) towards an external connector. I would do it with a BNC.

Cost-effective and reliable.

Here is how my ET5410 looks:

[cybermaus]

Those new A+ versions of the EastTester. What firmware version is it, and did anyone manage to get to the FLASH and download it?

[andyB2022]

Those new A+ versions of the EastTester. What firmware version is it, and did anyone manage to get to the FLASH and download it?

Did you manage to get the flash?

[cybermaus]

No, and also looking at the buttons a bit better, it's clearly different hardware, so the firmware would not work.
Still, what is, and who has, the latest firmware for the old model.

The latest mentioned here is  v1.02.2030 (year 20, week 30), but I do not even have that, I have V1.0.1942 (year 19, week 42)

[DaneLaw]

Got one of the old ones' just in the final weeks before the new (A) was the norm, but it was from Banggood from their EU store, when they cleared EU stock at attractive prices, so the unit I got' could have been in storage for some time.. - it arrived with this FW&SW.  (8 pictures down)  https://tinyurl.com/4ujvpybv

But its usually bag'ed for mobility, in lack of a dedicated lab bench.. https://tinyurl.com/yc64xbmp

[andyB2022]

Got one of the old ones' just in the final weeks before the new (A) was the norm, but it was from Banggood from their EU store, when they cleared EU stock at attractive prices, so the unit I got' could have been in storage for some time.. - it arrived with this FW&SW.  (8 pictures down)  https://tinyurl.com/4ujvpybv

But its usually bag'ed for mobility, in lack of a dedicated lab bench.. https://tinyurl.com/yc64xbmp

Is there any way you could try to dump the firmware off the STM32? I need it for my unit...

[DaneLaw]

Hi Andy, I saw your comment about your issue, but extracting the fw of the STM32 is sadly not something I can help you with.
Have you tried to contact East Tester?

This seems to be their sales email.
sales1@east-tester.com
Phone
+86-13396517215
+86-571-56770221

[andyB2022]

Yeah, no response so far.

[DaneLaw]

Yeah, no response so far.

If you do not hear back through email, then try the telephone (it's quite cheap these phonecalls to CN nowadays) and have your details ready, like serial number  etc, and emphasize that the phone support starts a case on your behalf, and ask for that case/journal-number, so you have something tangible to build on, if you have to call back, as otherwise, you can risk they just sing you a tune, on how they "love you long time, & will get back to you" and never do, and you have to start over and explain it all again to the next phone support worker.

[andobovsayvkub]

Hello. I just made a connection for 4 wires on 5410A+. I cut the traces and simply added a 22 ohm resistor between +V and +SENSE. Setting more then 20 Ohm will lead to an measurement error with 2-wires, and low values will cause voltage drop with 4-wires.
This made it possible to use both a 2-wire connection and a 4-wire connection without adding a switch. The standard behavior of the device has not changed.
Yes, it is possible that a voltage error may occur with a 2-wire connection but no more than 1 in the last digit on the screen. Tested in the range of 5-60V, 0-25A. And it still measures absolutely accurately with 4-wires connection. Also thinking of diode protection, but later.

part of original


new one


appearance


And one more moment. The motherboards have been replaced due to a transistor that burned out on the first day. And I can't remember if the "software sense" function worked correctly when measuring the resistance of the wires connected to the battery or to other weak source.
The line resistance measurements are correct with a laboratory power supply. But when I try to measure the line resistance with the battery connected, I get incorrect data as the source voltage has a drawdown. Is it like this for everyone or is the new board also defective?
That was my the main reason to transfer it to 4-wires schema.