Just pulled trigger on flea-bay:
$21.99 with free ship.
I have not seen a full reverse engineering of the frontend, but in the case of JoeQSmith's modifications, would it be out of it question to simply pull the OPA4330 and replace a higher bandwidth higher spec pin compatible AD8630 and tap the output directly or from the range switch? Or does it contain discrete filtering making this option a worse choice than making a seperate discrete parallel amplifier?
i dont think that can be answered without somebody drawing or finding (requesting??) a schematic.
true, mines in the mail i'll take the time when it does finally arrive to reverse as much as i can of the frontend and post here
i started working on the reverse engineering but in the end chose not to reverse the whole front end, its not filtered at the output, the output is very easy to access and the impedance of the meter on the current ranges is 150K
Its actually too unfiltered giving quite a bit of noise on the output so im going to be inserting an active low pass filter when i complete it
im waiting on the improved op amps to come in from digikey and will be posting what i did here in detail
Got a pic? I can but I'm not sure where R7 is.
Thanks BiOzZ.
looking at some pictures, I think I found the value. The resistor is marked as 471 (470ohms).
Hi,
I did the modification and worked fine. In the future, I will try to add an active filter to limit the bandwidth and noise on small signals.
Maybe using one OPA2344 and one additional switch (I don't know where) would be possible to select between two cutoff frequencies.
Anybody getting out of range even when no wire is present inside clamp on DC 2A mode? Got mine a few months ago, tested and it was working for DC current, but now it always shows out of range.
Zero function still keeps it out of range.
Edit: Sorry, searched it further, it just needs degaussing. I will build a degaussing coil, we will see how it works.
Before you go to the trouble of building a coil you could wave a magnet around near it. It should at least let you know if that's the problem, and if you're careful you may be able to get it back close to zero.
The other thing I've found that worked was a big reel of hookup wire attached to a 50hz source suitable for a sane current through the coil resistance (in this case a 24VAC CCTV PSU box) - no need to wind anything.
I need help. I pressed the blue and yellow buttons of my ut210e while turning on. CAL appeared on the screen. I pressed the blue button again. Random digits and letters appeared. Now my calibration is way off. It was spot on before. Kindly help me reset the calibration to factory settings.
I could not calibrate mine using this method. It says error 0 at the end. If i press select button while its calibrating it goes to volts option and volts start changing randomly. Kindly help me reset the calibration
I could not calibrate mine using this method. It says error 0 at the end. If i press select button while its calibrating it goes to volts option and volts start changing randomly. Kindly help me reset the calibration
Did you backup the Eeprom before you tried this ? not a good idea really , I thought this was for Factory use only.....
try messaging the poster @Indman in this post and see if he can help you...
https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg1109908/?topicseen#msg1109908
No i did not backup the eeprom . I had no idea it would do this. Otherwise I would have never done that
. Thank you for your tip on msging @indman. Lets hope he has a solution.
I have specially selected with big font
ATTENTION! To do only if there is a backup copy of EEPROM!If you haven't made it, then it will be very difficult to restore factory settings. I can offer only an firmware dump from other UT210E. Try to update an firmware this file. I have no other decision.
What range lost the calibration? I think a better idea is to use the same process and re-calibrate the meter.
Voltage in dc amps in dc. Basically all the useful calibrations went off
Normally the calibration affects just the selected scale.
In this case will be necessary a variable load and another meter as a reference. If I'm not wrong, a short press of hold button decreases the value and a long press increase the value.
I did not try using a variable load to calibrate. I will do that and post the results. Thanks for the idea
have you actually read the chip datasheet??
you need voltage and current references of a specific value!
have you actually read the chip datasheet??
Using Google translator (camera)
Section 12 talks about the calibration process.
you need voltage and current references of a specific value!
Not exactly.
In the calibration mode, the screen shows the measured value and you can change the "gain" pressing the hold button (if I'm not wrong). The unique limitation is the range of value and the minimum increment/decrement, e.g., you can change from 260mV to 270mV or 250mV, but the real value can stay between these values. Because of this, it's necessary a stable, but variable reference of voltage or current.
Here the schematic
(is public, found in conrad)
I had my 210E for a while and thanks to this thread, made mods on the AC/DC order at power on, 6000 count, 4hour auto power off, unlimited backlight, NCV in mV.
I wanted a second unit but it was not available locally so I got myself a 210D instead and also decided to do most of the same mods. Worked just as well! There were some little differences in the function addresses so I did not mess with them much, I just changed the DCV, ACV order, added mV function on the AC volts, 6000 count, auto shut off and backlight timers.
I also run my 210E with a li ion 10440 cell via a 3.3V LDO. Lasts quite a while and backlight is a bit brighter, beep is a little louder too.