Author Topic: Applent AT8612 DC load - a quick tear down  (Read 24238 times)

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Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #25 on: November 19, 2015, 04:28:48 pm »
thx you all for sharing your experiences.
Just ordered one Applent AT8612 in UK
http://www.tester.co.uk/applent-at8612-dc-electronic-load

 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #26 on: December 03, 2015, 10:41:39 am »
FYI
Just received a new Firmware from Applent (  from : vera at applent dot com ), this is the Version A2.9
No revision history available.

Now the Batterytest also shows the AH readings after a hard off from a smartbattery....
 
The first test with the Software Rev.1 from Applent ( thx. to thefamilyman ) was disappointing,
better to call it unusable...all readings/values from the AT8612 seems to scaled incorrectly and some inputs from the PC are not possible..
I am in contact with Vera from Applent an will inform you here if get any news
Torsten

« Last Edit: December 03, 2015, 10:52:05 am by AgiRigSig »
 

Offline thefamilyman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #27 on: December 04, 2015, 02:01:51 am »
FYI
Just received a new Firmware from Applent (  from : vera at applent dot com ), this is the Version A2.9
No revision history available.

Now the Batterytest also shows the AH readings after a hard off from a smartbattery....
 
The first test with the Software Rev.1 from Applent ( thx. to thefamilyman ) was disappointing,
better to call it unusable...all readings/values from the AT8612 seems to scaled incorrectly and some inputs from the PC are not possible..
I am in contact with Vera from Applent an will inform you here if get any news
Torsten

could you upload the latest firmware please?
 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #28 on: December 04, 2015, 10:34:41 am »
Hi thefamiliyman,

PM me your email and I'll send it to you :)

Have you made some test with the Software for the DC-Load?

 

Offline Danjensen89

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Re: Applent AT8612 DC load - a quick tear down
« Reply #29 on: January 13, 2016, 09:23:20 pm »
Hi Guys.
Very happy i found this thread. I have 2 of those and uses them in my shop.
I see you guys knows more about the units then i found in the manual.
I have 3 questions.
How do i upgrade the firmware? usb front?
Anyone wants to share the 2.9 version firmware? the hard reset battery test thats resetting the measured capacity is a major draw back for me.
Last question, some one also talked about software from applent site, i have searched that site down to ground, and dident fint that software, it would make my use of the units SO much better. Can anyone provide an link?

Regards, Dan.
 

Offline diyaudio

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Re: Applent AT8612 DC load - a quick tear down
« Reply #30 on: January 13, 2016, 09:44:51 pm »
VERY interesting, while the interface is different, the load portion itself is very much related to the Mayuno M9812 but with upgraded parts.

Maynuo:


Yours:
https://www.eevblog.com/forum/testgear/applent-at8612-dc-load-a-quick-tear-down/?action=dlattach;attach=159539;image

Yours has upgraded vertical sandstone resistors instead of the flat laying large wattage resistors. Yours has a higher quality R-core transformer. In general, the fit and finish look much better on yours than the Maynuo but there is VERY clearly a strong relationship between the designs. Everything is in the same general locations, most of the same parts are there, etc. It looks like one is a revision of the other and that is it.

EDIT: Your LCD-POO comment made me actually laugh out loud.

Someone needs to start reverse engineering these designs already, they all look similar and pretty straight forward
 

Offline ahakman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #31 on: January 22, 2016, 01:00:26 am »
Well, you can add me to the AT8612 owners list... at least once it arrives.

I'll be needing to switch it to 120V operation, which I don't suspect will be too difficult based on a previous post mentioning the transformer has 2 120V primary windings that are connected in series in the 220V model.

I actually couldn't find a 120V version anywhere, and especially not on Aliexpress!
 

Offline ahakman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #32 on: February 01, 2016, 01:43:37 am »
So my AT8612 arrived on Friday, direct from HK via DHL. It wasn't double boxed, and slightly damaged in shipping (the banana jack got pushed in and broke the plastic on the front panel a little). It did arrive with a US (110V) power plug, and the 110V/220V selector switch set to 110V on the back! So, was it actually ready to roll on 110V... probably not (but I never actually tried it). After reading a previous post in this thread that the 110 / 220 v switch wasn't connected, I did what Dave would do, and didn't turn it on, but took it apart!!





So, what do we have... yup, indeed the 110V / 220V selector switch IS NOT CONNECTED AT ALL:


Also, a bit of a design flaw with the ribbon cable of the display rubbing on the corner of the transformer mounting bracket... not good... hopefully the screen will still work...


Looking at the transformer, it indeed has 2 110V primary windings, and 2 secondary windings: a 13vac winding, and a +/- 13vac winding with center tap. A little common sense and looking at the secondary wires from the transformer leads to decoding the Chinese characters for Yellow Black and Green. A little googling to look up the Chinese symbol for Red and Blue, and you can easily figure out all the labeling on the transformer:


So originally on the primary, there's a plug that comes from the board and has blue and red going to the transformer, and yellow and black are tied together under a piece of heat shrink. Just out of curiosity, I plugging it in with 110V and measuring the open circuit voltage on the secondaries. You'll get 8vac on the green pair, and 16vac on the yellow pair, when we're expecting 13vac and 26vac respectively as per the label on the transformer. It's probably not going to work as is on 110vac input...



To reconfigure the transformer primaries for 110V operation, both 110V coils must be wired in parallel. I cut the red and blue leads going to the connector, and cut the yellow and black apart that were connected initially on the transformer. I connected red from the plug to red and yellow on the transformer, and blue from the plug to blue and black on the transformer to put the 2 110V coils in parallel. It's important that red and yellow be tied together, and blue and black be tied together so that the coils are actually in parallel. Now connecting it to 110V input and measuring the secondaries, I saw 16VAC on green, and 32VAC on yellow. Slightly higher than the transformer label, but to be expected as I'm measuring the windings open circuit with no load.




So, ready to go with 110V operation. Let's hope the display still works...


Yes, it does luckily! I put some tape over the damaged ribbon cable to prevent it from rubbing on the transformer mount in the future. I also fixed the contacts to the banana jacks and got that straightened out, but didn't take a picture.

In the end, it's quite easy to convert this unit from 220V input to 110V input, but don't trust what line cord it comes with, or the input voltage switch on the back!!
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #33 on: February 01, 2016, 11:56:42 am »
Hi ahakman,

sorry for your damage; I also received the unit via DHL, but mine was very well packed and arrived in good shape.

I'm quite happy with this device, but some details clearly call for unprofessionalism.
The power selection switch for all: if the unit is set for 110V and the switch is unoperative, someday there may be a problem... I would prefer to properly wire the selector switch, so that if it says 220V there's no risk to fry the unit by plugging it into a 200+ V socket (actually, I didn't do it, but anyway my unit is set to 220V, so there's no risk of damage).

By the way, I found that this electronic load works fine well beyond its nominal parameters.
Making some quick evaluation, it should be able to continuously bear up to 500W and 300V [it might also be able to work up to 40A, but the firmware (correctly) limits the input current to 30A/300V in every possibile configuration].

In fact, I could proficiently use it up to >800W during a few minutes, and finally managed to blow it with a 1500 W power spike (around 75V at 20A).
One of the power mosfets (IRPF460) went shorted, but the unit went back to life by simply cutting it out.
Anyway, to be sure I replaced all of the 8 mosfets along with their insulating pads (a couple of them were broken), and now everything works like new -
no burning mark anywhere

Some criticism:
- I found that removing the input plugs' locking nuts was more difficult than needed
- Also, the power resistors placement made it difficult to replace 2-3 of 8 mosfets
- The blinking blue light is somewhat annoying to me  :)
- I'd like to be able to finely calibrate the device, but the service menu is password locked and I wasn't able to get the password from Applent (i.e. from Vera). And the firmware is encrypted, too. Maybe anybody could help?  ;)
- The remote control software (thanks thefamilyman!) is definitely less than perfect... but way better than the incredibly bad software usually released with many Chinese products.

All in all, nothing to really complain about, and I find this electronic load very good for its price (no rake-off from the seller...)

    Lucio.
 

Offline ahakman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #34 on: February 01, 2016, 10:38:24 pm »
Yeah, you could wire the selector switch like this and actually have it be functional (actually I think looking at the picture I drew the diagram backwards - the 220V selection is on the left side of the switch looking at the contacts, so flip around the blue and red and the black wire tying the two switch contacts together). I'll probably never have this in a 220V place, so I'm not overly concerned and probably won't bother.

What do you mean, "removing the input plugs' locking nuts was more difficult than needed"? Are you talking about the nuts holding the banana jacks to the thick leads that go to the board? I actually found that mine were tight, but not _that_ tight. Pretty sure they're much tighter now when I put it back together. Yes, they're kindof a pain, but not too bad. Would be really easy with a 12mm open ended wrench, which I couldn't find quickly (the set that I had at hand had 11mm and 14mm :( ), so I used some large bent nosed needle nose pliers to do it.

Yeah, the blue light is a little annoying - doesn't bother me that much, but you could always cover it with tape, or find it's resistor on the front panel board and increase the value so the led isn't as bright.

I also read about and saw where you have to enter the password on the service menu. I'd like to re-calibrate mine as well - the voltage reading is off by about 10mV. The current is a little off (few mA) compared to the Fluke DMM, but it's not linear across the range I checked it over... probably not that significant unless you're trying to do really precise things...
« Last Edit: February 01, 2016, 10:45:46 pm by ahakman »
 

Offline Zbig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #35 on: March 30, 2016, 09:39:12 am »
Does it have slew rate (ramp-up/down rate) control? After a quick glance at the manual, I'm under impression that it doesn't, while the Maynuo 9800 series, based on the "similar" analog backend, do. Am I correct?
 

Offline hipfan75

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Re: Applent AT8612 DC load - a quick tear down
« Reply #36 on: May 21, 2016, 12:46:10 am »
So, thanks to the work of the earlier posters in this thread, and the fact that I too would purchase a poo with a colour LCD attached, I am now the proud owner of an AT8612.

One thing I'd like to point out to other prospective buyers is that the unit I received did NOT have a 110/220V transformer. On my unit, the primary was 220V only (see pic).  I have contacted Applent/Anbai to see if I can purchase a 110/220V transformer as seen in the earlier pictures in this thread.  I'll let you know how that works out.  Failing that, I'll just run it through an external step-up transformer.

Right now, I'm running it through my variac which can step up 110V to 250V. Looking good so far.  My unit, received yesterday, came with firmware A2.9.
 

Offline hipfan75

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Re: Applent AT8612 DC load - a quick tear down
« Reply #37 on: May 29, 2016, 01:20:46 am »
I have contacted Applent/Anbai to see if I can purchase a 110/220V transformer as seen in the earlier pictures in this thread.  I'll let you know how that works out.  Failing that, I'll just run it through an external step-up transformer.

So, Vera at Applent quickly responded to my query with a quote of US$70 (shipped to Canada) for the transformer.  I decided to stick with an external transformer, but credit to Applent for their excellent customer service.
 

Offline ivanroberto

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Re: Applent AT8612 DC load - a quick tear down
« Reply #38 on: January 01, 2017, 08:23:42 pm »
Hi, 
I need to calibrate my unit.
Vera from Anbai, told me that pass word is 861200
The problem is that there is no procedure description about to do this, and some buttons and sentences are in Chinese....
So,  if someone can help me with this, I healy appreciate.

Thanks in advance
 

Offline zocra

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Re: Applent AT8612 DC load - a quick tear down
« Reply #39 on: February 14, 2017, 07:09:48 pm »
It would be very good to know the procedure of calibrating the device, it would be good that the new firmware translate part of the calibration device

If anyone has a calibration process it would be nice to share it with others, thanks

I have A8612A and I am satisfied with it

 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #40 on: March 17, 2017, 03:33:53 am »
Add me to the I-need-another-LCD-instrument club. Just got my AT8612 fresh from Aliexpress. So far so good :-)

And one more installment in the 110V vs. 220V saga  >:D

I got a fresh unit build in Jan 2017.

Surprise! It came with a US power cable, a beautiful 110V/220V switch _and_ a little sticker marked 110V.
My hopes were high that after all that time they had added a proper voltage switch  :scared:  :scared:  :scared:



Before plugging it in, I opened it up to figure out what the wiring looked like (and to check if there was anything else needing attention). And... the voltage switch is not wired, as seen in other posts...  |O  |O  |O  |O



So I went to look at the transformer since some got one with 2 primary windings (110V/220V capable) while others got a single primary winding (220V only). And  ;D  ;D  ;D I got the dual winding one.

And then, triple bingo, it was wired in parallel, for 110V, just the way ahakman had proposed!  :clap:  :clap:  :clap:

So I got an actual 110V (non selectable) unit straight out of the factory   :-+  :-+  :-+



« Last Edit: March 17, 2017, 03:40:05 am by LaurentR »
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #41 on: March 20, 2017, 10:01:46 pm »
FYI
Just received a new Firmware from Applent (  from : vera at applent dot com ), this is the Version A2.9
No revision history available.

Now the Batterytest also shows the AH readings after a hard off from a smartbattery....
 
The first test with the Software Rev.1 from Applent ( thx. to thefamilyman ) was disappointing,
better to call it unusable...all readings/values from the AT8612 seems to scaled incorrectly and some inputs from the PC are not possible..
I am in contact with Vera from Applent an will inform you here if get any news
Torsten

Hi Torsten,
could you post the A2.9 firmware? Strangely, my unit is brand new and came with A2.3 and Vera claimed that A2.3 is the latest firmware. Weird.
Also, does anybody have any sw more recent than the v1.0.0 which has a number of issues?

Laurent
 

Offline DK-1

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Re: Applent AT8612 DC load - a quick tear down
« Reply #42 on: May 22, 2017, 08:12:04 pm »
If someone interested i just take the 2.5 upgrade for the AT8612A!
All seem to work perfectly....to be honest this upgrade has fix the only bug i had in my unit!
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #43 on: May 22, 2017, 09:41:28 pm »
If someone interested i just take the 2.5 upgrade for the AT8612A!
All seem to work perfectly....to be honest this upgrade has fix the only bug i had in my unit!

Hi DK-1. Which bug does the update fix? Could you post the 2.5 upgrade?

Thanks in advance.
 

Offline DK-1

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Re: Applent AT8612 DC load - a quick tear down
« Reply #44 on: May 23, 2017, 05:10:04 pm »
When i test the LED (in led window obviously) some function disappear.......i don't know why....anyway now it is been fixed!
P.M. for you LaurentR
 

Offline schmitt trigger

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Re: Applent AT8612 DC load - a quick tear down
« Reply #45 on: May 23, 2017, 05:11:43 pm »

 so the AT8612 became even more tempting at US$360+shipping.



The unit is within the correct price range for me too.
Mind you where did you purchase it?

The usual sites I've looked, are all above US$400 for the unit plus US$70 to US$100 shipping.
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #46 on: May 23, 2017, 05:51:29 pm »

 so the AT8612 became even more tempting at US$360+shipping.



The unit is within the correct price range for me too.
Mind you where did you purchase it?

The usual sites I've looked, are all above US$400 for the unit plus US$70 to US$100 shipping.

I bought it from this seller on AE:
https://www.aliexpress.com/item/AT8612-Programmable-DC-Electronic-Load-300W-150V-30A-3-5-TFT-LCD-RS232-Handler-Battery/32733874549.html
It was $368 + free shipping back in February. It has gone up a bit but still <$400 and free shipping.
 
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Offline sstepane

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Re: Applent AT8612 DC load - a quick tear down
« Reply #47 on: June 16, 2017, 07:40:53 am »
Hi there,

Just got the unit (AT8612, 220V).
The last firmware is 2.9 as Vera from Applent sent me the file (can share it if anyone needs it). Unit came with 2.5 version of firmware.
Another question I have cleared with Vera is that minimum resistance selectable is 0.1 Ohm even thought documentation says "resolution is 0.01 Ohm). I suspect that using SCPI it could be possible to select 0.0x values, have to test it.

Anyone knows any free software that uses SCPI language to gather data from the device? Original software is somewhat creepy and has no export to csv/excel data options so you could compare different tests afterwards (except for battery test - have to test it - if it exports the data and not only final results). In the end it is possible to write some small app that will do it..
 

Offline Kleinstein

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Re: Applent AT8612 DC load - a quick tear down
« Reply #48 on: June 16, 2017, 04:58:13 pm »
With electronic loads, one should be careful with higher voltages: The power MOSFETs usually have a much higher blocking voltage, but there also usually is an SOA limit. So at higher voltage the permissible power will go down (models go like proportional to voltage or voltage squared). The actual SOA limit when a FET will fail can very, often higher than specified, but no way to be sure.

The minium resistance is set by the shunts and the MOSFETs. The resolution is determined by the DAC and precision of the OPs. So there is no problem having resolution might finer than the minimum resistance. The actual limit might be a little smaller than the specs, especially of everything is cold.
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #49 on: June 17, 2017, 05:32:55 pm »
Hi there,

Just got the unit (AT8612, 220V).
The last firmware is 2.9 as Vera from Applent sent me the file (can share it if anyone needs it). Unit came with 2.5 version of firmware.
Another question I have cleared with Vera is that minimum resistance selectable is 0.1 Ohm even thought documentation says "resolution is 0.01 Ohm). I suspect that using SCPI it could be possible to select 0.0x values, have to test it.

Anyone knows any free software that uses SCPI language to gather data from the device? Original software is somewhat creepy and has no export to csv/excel data options so you could compare different tests afterwards (except for battery test - have to test it - if it exports the data and not only final results). In the end it is possible to write some small app that will do it..

Thanks to sstepane for providing the A2.9 fw.

I installed it successfully over A2.5, but now, I am getting a "Runtime error 9, subscript out of range" late into the connection process of the 1.0.0 software. Flashing back to A2.5 fixes the issue. Anybody either has this error or has been successfully running the 1.0.0 sw on A2.9 (or has a more up to date version of the sw)?
 


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