Author Topic: UNI-T UT61E Multimeter teardown photos. (Read 764934 times)

sdttn · « **on:** May 11, 2011, 05:19:47 pm »

I got the dmm from eBay for 65$ I do not know if it worth, what do you think?

Newer version

You can get full res version of these pics from sigrok wiki page

Drirr · « **Reply #1 on:** May 11, 2011, 05:52:33 pm »

I think that it is not bad at all. Three years ago i bought UT70B for 120$ $:-\$ . It has no true RMS, worse parameters and no acces to battery.

Kiriakos-GR · « **Reply #2 on:** May 11, 2011, 06:20:04 pm »

Quote from: sdttn on May 11, 2011, 05:19:47 pm

I do not know if it worth, what do you think?

Tell us more about your self , and what you do.
So to offer my opinion , about how close you got, at getting the right DMM for your needs.

sdttn · « **Reply #3 on:** May 11, 2011, 07:04:29 pm »

I am just a hobbyist.

Kiriakos-GR · « **Reply #4 on:** May 11, 2011, 07:24:02 pm »

Quote from: sdttn on May 11, 2011, 07:04:29 pm

I am just a hobbyists.

If so , then you got the most extreme DMM , for hobbyists . :-)

I just hope, that your PC also haves, an true Serial port at the back ( old style one ) .

sdttn · « **Reply #5 on:** May 11, 2011, 07:55:11 pm »

I have USB to RS232 converter cable the software can run with this cable, reading 2 value per second.

Fraser · « **Reply #6 on:** May 11, 2011, 08:11:45 pm »

I own several UNI-T multimeters and the UT-81B multimeter/scope. I know a lot is written about cheap meters often having serious issues with build or performance but I can honestly say that the UNI-T meters have yet to dissapoint me in service. For hobbyist use they seem extremely good value for money and IMHO have decent enough build quality for most hobbyist tasks.

After seeing Daves reviews on meters I went out and bought a FLUKE 87 III in 'as new condition'. That meter is my first choice for any measurements that I now make as it is a joy to use and is of superb quality. That does not mean I think any less of my UNI-T products though. Your meter looks very nice indeed and should provide you with good service.

tekfan · « **Reply #7 on:** May 11, 2011, 08:30:08 pm »

The input protection circuitry looks a bit whimpy but other than that the build quality looks excellent. I like how they didn't use just one of those ICs covered in a blob of plastic. The red board is also a special touch (getting quite tired of all the green ones).

It looks like you've got a really decent meter.

sdttn · « **Reply #8 on:** May 11, 2011, 10:00:26 pm »

Thanks for your reply.

By the way the DMM has not backlight function.
But the chip (ES51922) supports backlight function. The HOLD button is useless for me so I decided to use this button as backlight ON/OFF button.

DavidDLC · « **Reply #9 on:** May 11, 2011, 10:20:19 pm »

Nice hack !

What you need to do is to adapt a small circuit, so when you press the Hold key for 2 sec. it will turn on the light, if you just press and release the key it will act as regular Hold function key.

Also the circuit should automatically turn off the light after let's say 10~15 sec. to save battery.

pmrlondon · « **Reply #10 on:** May 12, 2011, 04:50:50 am »

I note that UNI-T tend to use BS1362 fuses - if they are suitable, why not? But then again, it does surprise me. It does bring the problem of someone fitting a higher-rated fuse - 3A and 13A are more common than 1A and 10A.

Nice backlight hack - was the hold function merely "push hold"? That is the main downside with my Amprobe...

ziq8tsi · « **Reply #11 on:** May 12, 2011, 07:47:41 am »

Quote from: pmrlondon on May 12, 2011, 04:50:50 am

I note that UNI-T tend to use BS1362 fuses - if they are suitable, why not? But then again, it does surprise me.

They are ceramic and sand-filled, with a typical interrupt rating of 8kA. And very cheap and available compared to DMM-specific fuses.

However, BS1362 fuses are only rated for 250V AC, and consequently the UT61E is labelled "250VMAX" on the current jacks.

So I would say that the choice of fuse is certainly not suitable for an industrial electrician, or anyone working with exotic high voltage supplies. Even if they never intentionally measure current.

For general electronics use it seems okay.

Kiriakos-GR · « **Reply #12 on:** May 12, 2011, 11:38:32 am »

Well , just the fact that UNI-T uses High Energy Fuses (capable to handle Arc - Flash ) ,
on instruments that are intended to be used at low-energy sources ( Amperes ) ( CAT I ) like the wall plug of your home,
proves that they care for the safety factor of their products .
And this is good.

But what pleases me more , are that all those explanatory information’s that our Dave ,
Shares with us , from his videos and teardowns ,
works out as educational material , and creates an new generation of informed DMM owners and users.
Who are almost able to identify, by an simple inspection of the inner parts, how the product stands up,
With the modern electrical regulations, or the given specifications’ by the manufacturer.
( The true bad made DMM’s does not have any hope, in such comparisons )

Even so it is wise, to not mix or compare specifications’, of bananas with apples or with pears.
Example : low-energy sources regulations and hardware demands VS High-energy sources = Unlimited Amperes )

We cause confusion by doing that.

saturation · « **Reply #13 on:** May 12, 2011, 01:33:09 pm »

Most excellent and simple hack. This chip is amazing, its a full Fluke type DMM on a chip, all inclusive. But I can't find it for sale anywhere. : es51922

Any clues?

Fox · « **Reply #14 on:** May 13, 2011, 11:05:38 am »

Just type the number it into Google.
The First Hit is the Datasheet of the Cyrustek es51922, a 22000 count Auto Dmm Chip.

saturation · « **Reply #15 on:** May 13, 2011, 11:39:01 am »

Thanks I know and have done this, but where you can buy it? Its not for sale anywhere: ocotoparts, findchips, etc., do not list it.

Quote from: Fox on May 13, 2011, 11:05:38 am

Just type the number it into Google.
The First Hit is the Datasheet of the Cyrustek es51922, a 22000 count Auto Dmm Chip.

sdttn · « **Reply #16 on:** May 13, 2011, 02:26:53 pm »

Quote from: saturation on May 12, 2011, 01:33:09 pm

Most excellent and simple hack. This chip is amazing, its a full Fluke type DMM on a chip, all inclusive. But I can't find it for sale anywhere. : es51922

Any clues?

You can ask for sample to Cyrustek.

Quote from: DavidDLC on May 11, 2011, 10:20:19 pm

Nice hack !

What you need to do is to adapt a small circuit, so when you press the Hold key for 2 sec. it will turn on the light, if you just press and release the key it will act as regular Hold function key.

Also the circuit should automatically turn off the light after let's say 10~15 sec. to save battery.

I can't desing the circuit.
The backlight has timer (60sec)
Thanks for advice.

Fox · « **Reply #17 on:** May 13, 2011, 05:20:12 pm »

Quote from: saturation on May 13, 2011, 11:39:01 am

Thanks I know and have done this, but where you can buy it? Its not for sale anywhere: ocotoparts, findchips, etc., do not list it.

Sorry, should have read your question more carefully.
Btw. Nice Hack.
Dave reviewed the UNI-T UT61D in his 100$ Mulimeter Shootout. Episode #99

saturation · « **Reply #18 on:** May 13, 2011, 07:11:29 pm »

Just my feeling on reading the spec sheet, this nice chip can potentially can get them into patent disputes with Fluke if the chip got into the USA; its my guess why its not available for direct sale; its likely available to ODM for end product design.

Quote from: Fox on May 13, 2011, 05:20:12 pm

Quote from: saturation on May 13, 2011, 11:39:01 am
Thanks I know and have done this, but where you can buy it? Its not for sale anywhere: ocotoparts, findchips, etc., do not list it.

Sorry, should have read your question more carefully.
Btw. Nice Hack.
Dave reviewed the UNI-T UT61D in his 100$ Mulimeter Shootout. Episode #99

stl · « **Reply #19 on:** May 17, 2011, 02:56:40 pm »

I also have this multimeter, as far as I can tell It's a lot more responsive than the UT61D Dave reviewed (but not as fast as my Fluke 12). I'm very satisfied with it, it's very good value for money. The one thing that really annoys me is the lack of an auto off function and on/off button.

Ronnie · « **Reply #20 on:** June 21, 2011, 12:07:42 pm »

I think the Analog Devices AD737J is the IC responsible for true RMS measurement.

kderh · « **Reply #21 on:** June 22, 2011, 06:00:01 pm »

I also have this UT61E Multimeter, apparently mine is an earlier revision with a green pcb and some component placement changes.

The only problem I have with this meter is the sh*tty uA / mA measurement because the shunt resistances are very high which drops up to 1V voltage at 220mA (or 0.8V at 2200uA)

Kiriakos-GR · « **Reply #22 on:** June 22, 2011, 06:41:52 pm »

There is a cure for this little problem ..

Send a message to Dave about this .. https://www.eevblog.com/forum/index.php?topic=1134.0

cuban8 · « **Reply #23 on:** June 22, 2011, 07:12:21 pm »

Yeah, the burden voltage of the UT61E is "shocking", as Dave would put it (there's also the possibility that he would call it "atrocious" instead):
I measured 1kOhm in the microAmps range and 10 Ohms in the mA range. Interestingly, the UT61D that Dave tested was pretty good as far as burden voltage is concerned.
I think I have to build myself a microcurrent device...

sdttn · « **Reply #24 on:** July 09, 2011, 05:34:10 pm »

Quote from: kderh on June 22, 2011, 06:00:01 pm

I also have this UT61E Multimeter, apparently mine is an earlier revision with a green pcb and some component placement changes.

The only problem I have with this meter is the sh*tty uA / mA measurement because the shunt resistances are very high which drops up to 1V voltage at 220mA (or 0.8V at 2200uA)

My DMM has same problem 1v @200mA.

Edit: Picproje.org forum üyelerine selamlar.


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Author Topic: UNI-T UT61E Multimeter teardown photos. (Read 764934 times)

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