KORAD 3005P, calibration? - Page 1
Forum section: electronics / testgear

author: MikeK
author_rank: Super Contributor
timestamp: May 13, 2022, 12:21:36 am
content: I found that mine outputs 0.51mA even with the output switched OFF. And when set to 5mA it actually outputs 7.8mA. Ugh.I checked the user manual, but no info. Can this be calibrated? At the very least OFF should be OFF!

author: Electro Fan
author_rank: Super Contributor
timestamp: May 13, 2022, 07:06:38 am
content: Here is a link to a post with an old calibration routine - there might be a newer one or one with better translation.https://www.eevblog.com/forum/testgear/korad-display-bug/msg1218999/#msg1218999

author: SHF
author_rank: Regular Contributor
timestamp: May 13, 2022, 11:29:54 am
content: I have something here in German

author: MikeK
author_rank: Super Contributor
timestamp: May 13, 2022, 02:00:53 pm
content: Is having 0.51mA with the output Off even a calibration issue? Why would there be any current at all? An output transistor leaking current?

author: Forester
author_rank: Newbie
timestamp: May 13, 2022, 03:20:44 pm
content: I have a KORAD 3010. When the output is off, the voltage is 6 mV, сurrent 3.6 mA. Measured Fluke 87V. Why so - I do not know.

author: Electro Fan
author_rank: Super Contributor
timestamp: May 13, 2022, 06:44:53 pm
content: On my Korad KA3005P when I set the PS to 9V, 20mA my Fluke 179 says 8.99V, 20mA with the output buttonon.With the PS still set to 9V, 20mA and the output button isoffthe Fluke says -112mV, -0.11mA.With the PS set to either 9V or 5V and 5ma and the output turned on I get 5.7mA on the Fluke.I found a newer version of the calibration routine (attached below) - probably worth giving it a try.EDIT: after warming up the 5.7mA reading became ~5.4mA.

author: MikeK
author_rank: Super Contributor
timestamp: May 13, 2022, 07:11:44 pm
content: They appear to be saying that you shouldn't expect better than 5mV and 1mA even when switched off.

author: Electro Fan
author_rank: Super Contributor
timestamp: May 13, 2022, 07:41:15 pm
content: Quote from: MikeK on May 13, 2022, 07:11:44 pmI have two Korad KA3005 units (one P and one D). Having gone through TEA, in addition to the two Korads, I've collected my share of meters (179, Brymen 789, KS 34465A, and more than several others). After doing plenty of measuring I think the Korad at just a little over $100 more than holds it's own. Try the calibration routine - it's a little bit hard to interpret but stick with it and I think you might be able to dial-in the Korad to an extent that will give you good confidence. Having said that, anything can fail and it's possible your unit has some issue but I wouldn't draw that conclusion until trying to calibrate it.

author: MikeK
author_rank: Super Contributor
timestamp: May 13, 2022, 08:14:37 pm
content: I tried the cal...that's the best I can get. I'll live with it. I might build Scullcom's millivolt meter for what I'm doing.Thank you.

author: ivo
author_rank: Regular Contributor
timestamp: December 11, 2024, 05:15:44 am
content: This worked to at least remove the horrible 5mA offset I had in my Tenma 3005P equivalent. You can use the left/right button to change the granularity of the adjustment, by changing which "digit" you are adjusting (even though they tend to all still indicate 0). The values I saw from the adjustment were quite unintuitive but from experimentation it seems to have improved it, at least, much better than you can by only adjusting the MSD. Very low mA measurement by the PSU is now usually less than a mA out. Unfortunately the voltage seems somewhat doomed in my unit by the DAC's INL. The low ranges (say <=5V) are a constant mV low, but higher (>=10V, where 30 is its full scale) are near bang on. Adjusting the 5A full scale is a bit tricky while my best A-range meter was constantly heating up it's shunt trying to measure