Author Topic: Review of the Korad KEL103 programmable load.  (Read 25058 times)

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Offline FriedMuleTopic starter

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Review of the Korad KEL103 programmable load.
« on: March 18, 2019, 02:41:09 am »

We have all been there, in trying to test a power supply, solar panels or battery's, we budge something together that shall make it out to bee a reasonable load, often do we use a lot of time to make sure that our load is somewhat okay or at least simulates the reality fairly, but nothing do replace a dedicated load that are already made for the job.

Then what to choose? You could naturally just get a Kikusui that properly are the leading manufacturer but not all of us has that amount of money, you could also just get a cheap no-name Ebay model, but are you then much better of then DIY?

We all know the BK Precision, Maynuo and the Rigol, funny enough Siglent does not make any loads, but is that all, aren’t there more in that price rang or maybe even better? In my search for an answer to that, I’d stumbled upon the Korad KEL-103 that is the same brand as my often used Korad 3305P power supply. Unfortunately could I not find much about it, until I’d contacted https://www.sra-shops.com/ that have almost all what Korad are making for private consumers, including the KEL-103 electronic load.


Many do all know what level of quality the Korad brand is and I would really like to know if the KEL-103 Electronic load was of high quality before buying / recommending the unit, so I contacted SRA Shops and asked if I could borrow a unit, and told them about my plan on reviewing it, before sending it back with thanks. SRA Shops was wary nice and liked my idea but offered me one for free, maybe knowing that after a tear-down, it may be worse off? When that is said, SRA Shops has in no way asked me to say anything in any particular way!

It has now been a month since I received the KEL-103 and I have tried to all from pampering to torturing it with some great and positive results.

But first, what do you get when buying the KEL-103 from SRA Shops?
The unit comes in a single layer cardboard box with nice padding to protect the unit. In the box, you get a professionally produced CD not that home copy stuff, a power cable, USB cable and a set of thick soft test cables. The manual is on the CD.

I have to say that the test cables caught my attention, they felt really solid and heavy I have no doubt that they can handle the 30A that KEL-103 can load, they have a really good feel to them and is wary bendable, down to 2 inch diameter without stressing them, pretty amazing.

The unit itself do also feel like a solid unit with a lot of holes in the bottom and back for the active cooling.
To me does the KEL-103 electronic load, looks a lot like the good old Keithly units, like the 2001, 2015 and so on.
KEL-103 has four feet's where the two in the front can fold out so the unit stands with a slight angel, that make it easy to use, the display is wary clear without been to bright, I feel that it has found the balance and you will have no problem reading the numbers on the front, not even outside in the sun.   

So how good is the unit?
In the shortest possible way, can I only say that if you love your Korad PS, you’ll also be glad for the KEL-103 Electronic Load! They are of the same quality and build.
To test the unit I kept a constant room temperature at 21,5 °C = 70 °F I started by connecting my Korad power supply to the electronic load, so a Korad PSU to test a Korad load, what can be more fair?
I did a lot of tests with different configurations but the largest difference was when the unit did stay turned on from yesterday but in rest run and then work for 4 hours at 18V 20A where I got a fluctuation of 6mV over the entire period. That's pretty impressive.
Under the tests I did not find the unit to make to much noise, okay you should avoid to put it in your bedroom but for an electronic load, the noise is acceptable.

This unit has a lot of functions with 100 memory functions, 5 presets you can program for easy change to what you use most. The unit is fairly easy to use when you know how, what I am saying is that you have to read the manual to get any good usage out of it. It’s not a unit that you just put into your lab and start using, because there are some functions that you have to read how to use before you get frustrated. But after reading this thin 25 page manual, you should easily be able to use it.

I had looked forward to the tear down and I have taken some picture but every chip, capacitor and what not, is covered by a black epoxy that make it nearly impossible to get much out of the tear down.


Conclusion: It is a unit you will like if you like the Korad brand, low noise and fairly stable, I do only not like that all components are without any kind of indemnification.
I think that this unit is worth the money and easily can compete with other brands like BK Precision and so on. The many functions and settings do make for a complete unit, you will not miss anything in your home-lab, unless you are working whit special advanced needs but then you may also own gear fare exiting this price range..


Facts:

For more info, please visit: https://blog.sra-solder.com/article-categories/power-supplies
« Last Edit: March 18, 2019, 05:02:35 am by FriedMule »
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Offline tautech

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Re: Review of the Korad KEL103 programmable load.
« Reply #1 on: March 18, 2019, 03:12:10 am »
funny enough Siglent does not make any loads
One is coming:

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Offline xani

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Re: Review of the Korad KEL103 programmable load.
« Reply #2 on: March 18, 2019, 08:17:46 am »
So I've got one too (the KEL102, lower power one) and so far it seems to be a solid piece of kit, and surprisingly quiet one (and I think fan just stop at low load). The biggest annoyance I found is as FriedMule mentioned that using of any non-basic function pretty much requires a manual because display does not display enough info to be used without it.

For example some modes lets you specify amperes of load and A/us but for both steps it just displays A on screen so you have to remember the order or refer to manual.

Battery mode is also a bit... derpy because you *have* to set both time and Ah which means you can't make (or at least I haven't found a way) discharge that lasts more than 9999 seconds (typing 0 just changes it to 0.001). You can just use normal CC mode but that won't show you Ah consumed...

If someone wants me to test anything specific let me know :)
 

Offline colorado.rob

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Re: Review of the Korad KEL103 programmable load.
« Reply #3 on: March 18, 2019, 02:23:22 pm »
funny enough Siglent does not make any loads
One is coming:
When?  Weeks, months, years from now?   :-//

My US vendor (as of last week) could provide no information at all as to when it will be available.
 
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Offline salvagedcircuitry

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Re: Review of the Korad KEL103 programmable load.
« Reply #4 on: March 20, 2019, 12:04:03 am »
@FriedMule Awesome review man!
I was on the verge of buying one of these and testing it out, but I happened to score a pretty fancy dc electronic load not too long after. I paid about 2.5x what this Korad costs, but it's a whole lotta dc load for one to handle  ^-^. I'm still reading the manual on mine  ;D
I'm glad this turned out to be a pretty sweet unit.
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Offline tautech

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Re: Review of the Korad KEL103 programmable load.
« Reply #5 on: March 20, 2019, 04:23:11 am »
funny enough Siglent does not make any loads
One is coming:
When?  Weeks, months, years from now?   :-//
As usual release date is a secret however mid (this) year was mentioned. So a couple of months or so.  :(
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Offline nctnico

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Re: Review of the Korad KEL103 programmable load.
« Reply #6 on: March 20, 2019, 10:55:39 am »
Why do so many loads have these stupid binding posts which don't take 4mm banana plugs? There are 4mm binding posts which are rated for 35A so that isn't the problem.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline colorado.rob

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Re: Review of the Korad KEL103 programmable load.
« Reply #7 on: March 20, 2019, 05:08:01 pm »
Quote
Why do so many loads have these stupid binding posts which don't take 4mm banana plugs? There are 4mm binding posts which are rated for 35A so that isn't the problem.

I suspect that it is because EU safety rules requires fully-sheathed banana plugs, which makes also providing reasonably-sized binding posts difficult for smaller form factors and would make the product more expensive to produce.

I just discovered that the reason for this rule in the EU is because mainland European power outlets are a perfect receptacle for a 4mm banana plug -- and a match for the 19mm spacing of a dual banana plug connector.
 

Offline JeffreyLatter

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Re: Review of the Korad KEL103 programmable load.
« Reply #8 on: March 20, 2019, 05:23:25 pm »
Thank you for the great review!  :-+
Have been thinking about buying this one - this probably does it..   :-DD
 

Offline Commander_Spock

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Re: Review of the Korad KEL103 programmable load.
« Reply #9 on: April 29, 2019, 01:51:06 pm »
outside of ebay anybody knows where i could find it in the european union ?
 

Offline txx

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Re: Review of the Korad KEL103 programmable load.
« Reply #10 on: August 07, 2019, 10:24:20 am »
It looks like this RND brand is a rebrand of Korad. And that they can be bought from elfa: https://www.elfadistrelec.dk/da/programmable-electronic-dc-load-120v-150w-30a-rnd-lab-rnd-320-kel102/p/30126023?track=true.

Regards
 

Offline plazma

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Re: Review of the Korad KEL103 programmable load.
« Reply #11 on: October 04, 2019, 02:00:56 pm »
outside of ebay anybody knows where i could find it in the european union ?

Farnell got it rebranded as TENMA. Quite a good price. https://uk.farnell.com/tenma/72-13210/dc-electronic-load-prog-30a-120v/dp/2848407
 

Offline tooki

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Re: Review of the Korad KEL103 programmable load.
« Reply #12 on: April 07, 2020, 09:47:32 am »
It looks like this RND brand is a rebrand of Korad. And that they can be bought from elfa: https://www.elfadistrelec.dk/da/programmable-electronic-dc-load-120v-150w-30a-rnd-lab-rnd-320-kel102/p/30126023?track=true.

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RND is the Dätwyler group’s new house brand (as of a few years ago), so all the Distrelec companies as well as Reichelt, all being Dätwyler subsidiaries, now sell the RND products and push them heavily.
 

Online gaminn

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Re: Review of the Korad KEL103 programmable load.
« Reply #13 on: July 07, 2020, 01:00:32 pm »
I downloaded KEL103 programmable software here http://www.koradtechnology.com/nav/19.html. It contains:

KEL103.exe - a communication debugging utility, that can connect to my KEL103 over LAN and send commands to it. But it is not user friendly, it is just a test utility.
KEL103 software - this is user friendly software, but it can communicate with KEL103 only via serial port (or USB).

What software do you use to control KEL103 over LAN?
 

Offline damianzet

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Re: Review of the Korad KEL103 programmable load.
« Reply #14 on: August 05, 2020, 02:34:32 pm »
Hello guys. I have this load and some of the components are burnt on mine. R155 and Q11 as well R166 but i know its 471 resistor. Can anyone share what components values are in Q11 and R155?

« Last Edit: August 06, 2020, 08:37:30 am by damianzet »
 

Offline Hydron

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Re: Review of the Korad KEL103 programmable load.
« Reply #15 on: August 05, 2020, 03:59:20 pm »
outside of ebay anybody knows where i could find it in the european union ?

Farnell got it rebranded as TENMA. Quite a good price. https://uk.farnell.com/tenma/72-13210/dc-electronic-load-prog-30a-120v/dp/2848407
CPC (basically less competent but cheaper farnell) is significantly cheaper for those in the UK:
https://cpc.farnell.com/tenma/72-13210/dc-electronic-load-prog-30a-120v/dp/IN07979?st=electronic%20load

Wish they had a higher voltage version though

Edit: Damnit now there is a good chance I'll ending up buying one to feed the TEA habit...
« Last Edit: August 05, 2020, 04:02:40 pm by Hydron »
 

Offline Saskia

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Re: Review of the Korad KEL103 programmable load.
« Reply #16 on: August 05, 2020, 04:08:05 pm »
found one of those for reasonable money on a returns shelf. It was still in the original packaging, so I could not resist.
 

Offline doktor pyta

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Re: Review of the Korad KEL103 programmable load.
« Reply #17 on: August 07, 2020, 09:16:27 am »
Can it make battery test (counting Ah) in constant power mode?
I would appreciate if someone could confirm this.

Offline HKJ

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Re: Review of the Korad KEL103 programmable load.
« Reply #18 on: August 07, 2020, 10:02:13 am »
Can it make battery test (counting Ah) in constant power mode?
I would appreciate if someone could confirm this.

You can always control it from a computer with TestController and do it that way.
https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/
Note: TestController do not have a definition for Korad KEL103 at the moment, but it is fairly easy to make (No programming required).
Note: TestController have support for Itech, Maynuo & B&K loads, this means with these you can measure Ah in constant power mode.
 

Offline Hydron

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Re: Review of the Korad KEL103 programmable load.
« Reply #19 on: August 10, 2020, 02:41:09 pm »
Hello guys. I have this load and some of the components are burnt on mine. R155 and Q11 as well R166 but i know its 471 resistor. Can anyone share what components values are in Q11 and R155?


I don't have one (yet) so unfortunately can't help, but could you shed some light on what happened that cuased them to burn up? Was it just sitting there, or was a high voltage or something applied to the inputs that shouldn't have been? Asking as I'm considering buying one (in which case I'd open it and look at this area of course!)
 

Offline ahope

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Re: Review of the Korad KEL103 programmable load.
« Reply #20 on: August 10, 2020, 05:48:48 pm »
Hi,
Here are some snaps from mine.

Hope that helps.

/andreas
PDP10 6502 6809 68000 PDP11 8088 x86 ND5000 STM32 ESP32
From bare metal to the cloud
 
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Offline rsx90

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Re: Review of the Korad KEL103 programmable load.
« Reply #21 on: August 10, 2020, 07:33:35 pm »
Hi guys!

Q11 marked "1AM" is most probably a MMBT3904L NPN transistor: https://www.onsemi.com/pub/Collateral/MMBT3904LT1-D.PDF

From the picture it's clear that the gate drive circuitry of Q13 was affected. You should also check D11, D12, D13, U32 opamp and Q13, there are chances that some of these are be blown too.

As Hydron also asked, what had caused the failure? Wrong polarity connection to a battery?


Best regards,

rsx90
 

Offline subliti

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Re: Review of the Korad KEL103 programmable load.
« Reply #22 on: August 11, 2020, 08:48:30 am »
Can it make battery test (counting Ah) in constant power mode?
I would appreciate if someone could confirm this.

No, battery test mode supports only CC. But ofc combined with a pc you can make your own tool that counts AH in any mode.

Also here some clarification about the unit/manual:
The manual is garbage. For example...in battery test mode you have to specify (even if you dont need it) a max discharge time limit and consumed AH limit. The manual states that this is in seconds (discharge time) but this is wrong. You can set the max time to 9999, but this is minutes and not seconds.  The same with AH, its 9999 AH.
The manual is also wrong/confusing with different other things.
 
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Offline ahope

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Re: Review of the Korad KEL103 programmable load.
« Reply #23 on: August 19, 2020, 12:52:21 pm »
I have blown up my KEL103. 12V Lead Acid batteries should not be connected the wrong way.

I have replaced one of the 5W resistors on the input.

Now U8, a 7812 +12V regulator goes burning hot and nothing works. Looking closely on the pcb I see C135, C136 and C 137 are burned up (?).

Anyone know their value? If you have a KEL103, can you measure them?

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Offline ercapoccia

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Re: Review of the Korad KEL103 programmable load.
« Reply #24 on: August 19, 2020, 01:08:34 pm »
Did you check for shorts? I'm not familiar with this device, but for sure there is a short somewhere.
 


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