Kunkin KP184 electronic load : "fixing" an manufacturer issue

[patman27]

Alas, my unit's buried deep in storage and will be for some time. That's the best photo I got from when I chose to not turn it on but take it apaaaaht.

Does anyone else have their Kunkin handy?

[aristarchus]

Part number : ZOV-10D181K

Hi everyone!

I need your help. The Varistor (marked VDR1 next to the relais and + terminal) blew up. Sadly the face holding the identification is all charred. Can some of you guys have a look into your unit and tell me which type it is? The part-Number (or at least niminal voltage rating) would be awesome.

I just don't want to fly blind and go with a 150/160V type of random rating.

Thank in advance and best greeting!

[Faron]

You're my hero of the day! Thank you!

Part number : ZOV-10D181K

[ArsenioDev]

Weird problem with my load, left it powered up overnight on a test run maxing out at 40W and when I checked it in the morning it had no voltage sense displayed and the display was strobing at around 60hzish on top of the normal illumination. Took a look inside with the FLIR and WOW something went VERY wrong, the ADC was casually just hanging out at 300+ degrees. Probed around the test points and the only one being weird was the -5V rail. Traced it to what appears to be its reg but that is running normal temps but at 5V, not -5V, it's a SOT-23-6 with the label "CA74" but my google-fu found nothing. Spent a few hours trying to figure out why the heck this thing blew it's ADC to no avail, need to have this thing online soonish when I do power stage testing and would rather not have to buy a new one. Any ideas would be appreciated.

[PaWill68]

I got new Kunkin software for KP184 (v4 202004) 2021.02 v1.0.13. Previous versions did not connect to my electronic load.
https://disk.yandex.ru/d/5MizUcHimwxMIw

[interflexo]

Latest version is 1.0.24.0 from 29 April 2021.

You can find it's thread and download links here:

Serial to usb on Kunkin KP184 electronic load

[PaWill68]

interflexo, for me, buying for 30 USD is expensive with a salary of 200 USD.

[interflexo]

PaWill68 please send me your request by email and I will be happy to help you with the KP184 Modbus software registration.

[PaWill68]

interflexo, thanks for your offer of help. Your software is very good, but I am very used to using TestController and yesterday it started working with KP184.

[oz2cpu]

NEWS : C58 in my KP184 was 10nF originally
my KP184 was unstable at high input voltage 150V and low current 0.7A
so i tried to remove that cap, and now my unstability is much improved,
it still current ripple much more than my more serious brands of DC loads, but now i think i can learn to live with it..