UNI-T UT61E Multimeter teardown photos.

[Thilo78]

@Thilo:

Which version of the UT61E software did you try: v2 or v4?

Did you already try DMM (https://www-user.tu-chemnitz.de/~heha/hs/UNI-T/ )?
From the infos on that page it is not clear whether you can log two UT61E or not.

-Didix

*UT71E 
I have two identical (with succeeding serial numbers, so same batch I suppose) UT71E, directly bought in China.

First, I used the software, which I downloaded earlier. It's v2.00, IIRC.
Second go, I used the current software v3.00.

edit: Both ways didn't work.
I'll have to check with my laptop, using USB ports without a hub.
Maybe tomorrow or next weekend, as I'll be away in between.

I didn't yet try the DMM software you linked.
I'll check it a.s.a.p. 

[Didix]

Yes, sorry, I have overseen that you have two UT71E.

I ask myself, whether it matters, what software you take. They look all the same and DMM seems to talk to all Uni-Ts.

However, to put the question again into the ring: does anybody have two UT61E?

I'll never give up! 

-Didix

[Thilo78]

I'm not perfectly sure, if the type matters if both meters are the same.
But it occurred to me, that it works if you have two different meters. Maybe the USB identifier is different between UT71E and UT71D or other combination....   

Let me try, if I can manage to hook up the two UT71E by using direct USB connection.

[crystal]

Actually if I understand things correctly, the GS version is sold in Germany and it has a different design. The GS version has better input protection but has a lower CAT rating. The information is here on the forum somewhere and in this thread I think.

After having both the UT61E and the UT139C I recommend the UT139C instead, if you don't need the PC connection.

OK maybe there are really some different versions on the market with different certifications and cat ratings . Maybe this would be the reason of the price here in Europe . They let pay the GS certification by the german customers for lowering the cat ratings . Crazy business 

This is the German GS version:

[centaurian]

crystal: Interesting. So it differs from Chinese version with 4 MOVs and bigger fuse holders - https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/msg545943/#msg545943 (Also, there is missing VR5 calibration resistor for 10A range on that GS version).

So what's fuse voltage rating and type of MOV used in GS version?

[Didix]

Did you already try DMM (https://www-user.tu-chemnitz.de/~heha/hs/UNI-T/ )?

I have been talking to the author of DMM.
This seems to be our program 

You should be able to start two instances and connect two DMMs and each instance catches a DMM.
Each instance should then write its own logfile.

However, you will not get a single logfile with synched data. You have to do the sync after logging.
Well, that's ok for me.

Would be nice if somebody who owns two UT61E with USB interfaces could make a test 

-Didix

[Thilo78]

[...]
Would be nice if somebody who owns two UT61E with USB interfaces could make a test 

-Didix

Basic test with 2 UT71E: Works.

After startup of each instance, you can select between USB1 and USB2, and then display the data from the meter.
From the window you can select "Log to file" and then define a log file name for each window.

Trap for young players: Don't forget to activate "Send" on the UTs. Otherwise you might curse and search for a minute or so 

Nice tool. Not beautiful, but it does its job.

btw: Tried the same with the UNI-T software v3.00, but with the original USB ports of my laptop:
Actually it works with two instances, but if you open the second window, both will log data from the same unit 
Apparently, it's not intended to be used with identical meters...

[Didix]

Perfect!

Looks that I need to order one more ...

Thanx fo testing !!

-Didix

[Thilo78]

You're welcome!
Gern geschehen! 

I knew having two UTs might come handy one day 

Another question:
Just took one of the UT71E apart. Although they are original Chinese, non-export versions, the PCB seems to be ready for upgrade with HRC fuses and additional MOVs (one is present, the other spots are unpopulated). I just can't recognize if the MOV spots have traces to them...

Is it worth to take care of these parts as a weekend project? 

[Rick Law]

Did you already try DMM (https://www-user.tu-chemnitz.de/~heha/hs/UNI-T/ )?

I have been talking to the author of DMM.
This seems to be our program 

You should be able to start two instances and connect two DMMs and each instance catches a DMM.
Each instance should then write its own logfile.

However, you will not get a single logfile with synched data. You have to do the sync after logging.
Well, that's ok for me.

Would be nice if somebody who owns two UT61E with USB interfaces could make a test 

-Didix

I don't have two UT61E, but I often connect my UT61E along with other devices also connected to the PC.

If all else failed....

The UT61E sends out data in standard 7 bit ASCII.  (8 bit word but MSB is always zero).  A TTY terminal emulation program will capture it nicely (and save/log to file.)  So you can just start multiple instances of something like Hyperterminal and log the lines to file.

While it is feasible to capture different devices to different text files, it gets a little messy when the lines are not individually time stamp-ed.  So, I found it easier to just write a Java program to grab the data from different ports (different devices) and log it to single file with PC's time stamp.   I suppose you can write one with BASIC as well.  My version of Basic supports only COM1 & COM2, so JAVA for me is easier and can use any COM port.

[crystal]

crystal: Interesting. So it differs from Chinese version with 4 MOVs and bigger fuse holders - https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/msg545943/#msg545943 (Also, there is missing VR5 calibration resistor for 10A range on that GS version).

So what's fuse voltage rating and type of MOV used in GS version?

The pic is from another thread, it seems I just can't find it now. I think I read somewhere fuses are 600V rated. Greetings

[Mikeva]

hi guys!
it's been 2+ months since i bought the 61E and everything was ok until today....
I had an old transformer that i wanted to measure and wanted to figure out  which pins are for the primary 220v and which are  for the secondary 12v. Unfortunately by my mistake  i plugged the transformer giving the 220v on to the secondary and the result was to blow the multimeter.Didn't understand why that happen despite that the scale was on the ac volts as it should.....Now it's dead.Won't turn on.The fuses are ok,the ptc's seems ok ,the rectifier diode also ok.Any ideas?

[Maxlor]

Not exactly sure I understood you correctly, but if you wired the transformer up backwards you'd get near 4000V out of it. That's plenty enough to kill the UT61E, it's not sufficiently protected against high voltage.

[crystal]

hi guys!
it's been 2+ months since i bought the 61E and everything was ok until today....
I had an old transformer that i wanted to measure and wanted to figure out  which pins are for the primary 220v and which are  for the secondary 12v. Unfortunately by my mistake  i plugged the transformer giving the 220v on to the secondary and the result was to blow the multimeter.Didn't understand why that happen despite that the scale was on the ac volts as it should.....Now it's dead.Won't turn on.The fuses are ok,the ptc's seems ok ,the rectifier diode also ok.Any ideas?

Check all the passive components. If it's still dead then the main chip is fried. You could try contact the crystek for the replacement chip, maybe they will sent you the new one. Then if you are skillful enough change it but you will probably need to recalibrate the instrument.

PS:
Why in the hell would you check the unknown transformer like that? You could be dead, what about if it was less that 12V secondary? I always check the unknown transformer by measuring resistance and try it on mains with nothing attached to it and me on a distance.

[Mikeva]

Yeap that,was stupidity from me.  Now I've learned my lesson....
Well, i'll check the components to see if something manage to stop all the voltage, but if it's the main chip that burned then i will throw it away and buy a new one.

[Yago]

Don't throw it away, might be handy for parts and spares.

[Mikeva]

No i won't.I'll keep it for spare parts   since it's brand new 
the only thing it does right now  is when i connect the battery it's beeping like that: 1 beep then pause a sec,then beepping 7-8 times.Could this indicate something?

[Wytnucls]

It's trying to play the funeral march of Chopin:

[Mikeva]

 

[Rick Law]

That smilie means what?  You managed to revive your UT61E?

[Mikeva]

That smilie means what?  You managed to revive your UT61E?

No,unfortunately!
I m laughing about the funeral march  that Wytnucls posted  above!

[Steps]

You should drive the backlight leds with transistors. It will safer than old hack.


Taken from UT60E dmm schematic.

In this configuration, couldn't the same protection be achieved by only using a single NPN rather than the complementary config shown here?

Hello Colleagues!
I going to do power off mod and backlit mod (with permanent light, not original). And I want that light will be off after DMM going to sleep. Can I connect +V of the LEDs to the positive side of C33, like for the IR transistor?
And should I add driving the backlight leds with transistors like in UT60E schematic?

[rr100]

I had an old transformer that i wanted to measure and wanted to figure out  which pins are for the primary 220v and which are  for the secondary 12v. Unfortunately by my mistake  i plugged the transformer giving the 220v on to the secondary and the result was to blow the multimeter.Didn't understand why that happen despite that the scale was on the ac volts as it should.....Now it's dead.Won't turn on.The fuses are ok,the ptc's seems ok ,the rectifier diode also ok.Any ideas?

The idea (for the next time) is to check the resistance with the multimeter first, for sure the primary would be the highest.
I am surprised nothing else blew first - and I wouldn't trust the isolation on that transformer anymore not to start a fire or electrocute somebody.

[snowsnee]

Hey Guy Gals,

 New here, I got 2 UT61Es new I will post the backs open pictures and calibration. So far this to note UT61 series is the backlight UT61E does not have one. That series 61d or c b a may have one . Another note calibration right on 10.000, on two AD584KH with calibration stickers 10,001 cant calibrate right on the money can't calibrate nothing perfect. I asked some of the big time dealers AD584LH (not needed sticker notes I think ?) no calibration or AD584KH with calibration. One dealer selling AD584LH he said right now its AD584KH with calibration sicker to go by. Took a week of study nothing, so I just asked them the dealers which is best.

 So the one UT61E got from China $47 I got is accurate. UT61E $48.00 next I get I am getting from a dealer China 1000 miles away from each other. I will check the calibration to the other. I have 3 AD584KHs with sticker calibration set written (one coming still) to check accuracy then I will take apart show pictures of both if the same or not. (Note can't buy another multimeter better so I got 2 just because of the documentation this model.)

Edit: Now China dealer says ( yes, sure, there is a sticker) . AD584KH Dealer.   
Edit again: AD584LH ( it don't need calibration said big dealer eBay ) So it was like thought. And AD584KH does need the sticker calibration.

[snowsnee]

This is new Jan 31 2015.  Voltage reference: (10 VDC)  Was 10.000 VDC OK  on upper one not adjusted. Was 9.998 VDC Now 10.000 on the other corrected bottom one. You can adjust further. Looks like same boards new out of China.