Kunkin KP184 voltage meter unstable - Page 1
Forum section: electronics / testgear

author: the-powl
author_rank: Newbie
timestamp: April 02, 2025, 06:08:30 pm
content: Hi there. I just received my Kunkin KP184. So far it seems to work as expected but I noticed, that the voltage meter is a bit unstable. It constantly fluctuates by several mV, even when I connect it to a stable source (battery pack) and disable the load. From many videos about this electronic load I found, that this is not normal behavior. Any ideads if it's some issue with the newer models/FWs or is something wrong with my unit? I know it's a fairly cheap electronic load but a fluctuating measurement instrument is rather annoying to me. Should I try to return it and buy another unit?I've got FW version 2307 and Board Ver.07.Here's a video where I have my battery pack conneted to the load:https://youtube.com/shorts/cr2XjX1a1C8

author: interflexo
author_rank: Regular Contributor
timestamp: April 07, 2025, 07:25:50 am
content: That is not the normal behaviour of a Kunkin KP184 unit. You should return it and get another working unit.

author: the-powl
author_rank: Newbie
timestamp: April 07, 2025, 10:22:46 am
content: Thank you for your reply! I'll try getting another unit.

author: the-powl
author_rank: Newbie
timestamp: April 08, 2025, 06:19:34 pm
content: I just received my second unit (still trying to return the other one), apparently same firmware, suspiciously same package and same warehouse. Excatly same behavior! Are all the newer models flawed?Alsowww.kunkin.comis not reachable any more. Is this company dead?

author: SpecialK
author_rank: Regular Contributor
timestamp: April 08, 2025, 07:49:47 pm
content: I replaced the banana jacks after watching a Voltlog video:They apparently aren't the standard size. Also, in 4-wire mode you would use the BNC port for more accuracy. Maybe that would be more stable too?

author: the-powl
author_rank: Newbie
timestamp: April 08, 2025, 08:21:01 pm
content: unfortunately no. The stability of the volt meter reading is not a matter of an unstable connection in this case.(Although I'd definitely replace that banana jacks if the unit would work fine)

author: interflexo
author_rank: Regular Contributor
timestamp: April 09, 2025, 09:26:26 am
content: I am curious about the capacitance installed on the KP184 PCB where the (+/-) power cables exit to the front panel binding posts (in parallel with the load).https://www.eevblog.com/forum/testgear/electronic-load-with-low-shunt-capacitance/msg4303024/#msg4303024First KP184 units had a current slew rate limit of 200A/ms. Later units will go to 400A/ms.I wonder if they are fiddling with this capacitance. 2uF should be the expected value there.

author: the-powl
author_rank: Newbie
timestamp: April 11, 2025, 08:53:21 am
content: interflexo, I just tried your software. Awesome piece of work! I just decided to keep the KP184 so I can open it up soon and have a look at the internals again. Would be awesome though if I'd find a fix for the unstable voltage meter. I'm wondering if it's a firmware issue or if they changed something on the circuit. Makes me wonder why anyone would do this if the units before were working perfectly fine.

author: Hamelec
author_rank: Regular Contributor
timestamp: April 21, 2025, 10:03:15 am
content: Quote from: the-powl on April 11, 2025, 08:53:21 amPlease report!(having the same issue here)