300W DC Load: Korad KEL2010 or Tonghui TH8402A ?

[nctnico]

I'm contemplating on getting a DC load to replace my Agilent N3301 which is quite large and with it's 600W rating it is overkill for many jobs that I have.

So I went looking around to see what kind of DC loads are out there. A hard requirement is to have banana jacks on the front. The Korad KEL2010 and Tonghui TH8402A caught my eye. Specs are in the same ballpark although the Tonghui has more functionality and in my mind Tonghui is a higher quality brand compared to Korad.

Tonghui:


Korad:


A dillema with a purchase decission is that I can buy the Korad locally but the Tonghui is only available from Aliexpress. So if there is something wrong with the Korad, I can return it and/or get support. If there is something wrong with the Tonghui, I'm left with an expensive doorstop. And then there is also the more expensive (and bigger) Tonghui TH8202A which has 3 measurement ranges and might be more suitable for dealing with low currents.

I have not been able to find any reviews so it is hard to tell which one is a good buy. Has anyone tried one of these loads?

[trp806mo]

I Have a multicomp (but it's a Korad). I made a review of the Sigelnt SDL too (in it's thread) so if you want a dedicated measure/feeback  let me know.

[PartialDischarge]

I'd get a Rigol DL3031 and add banana to spade adapters to the terminals if they are that important.
I'm not recommending Siglent here as I have one (SDL1020) and it gives me random startup boot errors.

[nctnico]

I'd get a Rigol DL3031 and add banana to spade adapters to the terminals if they are that important.

The price for the DL3031 is about twice of that of the Korad / Tonghui for similar or even better specs.

[tautech]

I'm not recommending Siglent here as I have one (SDL1020) and it gives me random startup boot errors.

Using which FW version ?
It your running the latest ?
https://int.siglent.com/download/firmwares/?CateIdss=12

[PartialDischarge]

I have the 1.1.1.21R2, latest seem to be 1.1.1.22

What happens is that randomly gives an error at startup, and then you have to turn off/on again until it works. The avarage is 2 times, not much, so I just don't care since I use it sparingly

[tautech]

I have the 1.1.1.21R2, latest seem to be 1.1.1.22

V1.1.1.22R1 actually.
Suggest you install it. 

[PartialDischarge]

I'd get a Rigol DL3031 and add banana to spade adapters to the terminals if they are that important.

The price for the DL3031 is about twice of that of the Korad / Tonghui for similar or even better specs.

Well I guess that’s the price to pay for probably a more widespread equipment, in any case I wouldn’t buy an equipment with a single character in Chinese in the UI, shows lack of commitment from them to sell abroad

[Martin72]

A dillema with a purchase decission is that I can buy the Korad locally but the Tonghui is only available from Aliexpress.

Or here:
https://www.globalmediapro.com/dp/A2MY50/Tonghui-TH8402-Programmable-DC-Electronic-Load/?setCountry=NL#Includes

https://www.globalmediapro.com/content/about
Edit: Crap
From Korad we have exactly one DC-Supply, it´s a typically chinese cheap one.
We also have 2 300W DC Loads from Rigol, good ones but complicated to use.

[nctnico]

I'd get a Rigol DL3031 and add banana to spade adapters to the terminals if they are that important.

The price for the DL3031 is about twice of that of the Korad / Tonghui for similar or even better specs.

Well I guess that’s the price to pay for probably a more widespread equipment, in any case I wouldn’t buy an equipment with a single character in Chinese in the UI, shows lack of commitment from them to sell abroad

The menu language on the Tonghui can be switched to English and there are English manuals available from Tonghui that show the screens in English. So there is no lack of commitment to sell abroad. Tonghui has been around for nearly 30 years already.

A dillema with a purchase decission is that I can buy the Korad locally but the Tonghui is only available from Aliexpress.

Or here:
https://www.globalmediapro.com/dp/A2MY50/Tonghui-TH8402-Programmable-DC-Electronic-Load/?setCountry=NL#Includes

https://www.globalmediapro.com/content/about

From Korad we have exactly one DC-Supply, it´s a typically chinese cheap one.
We also have 2 300W DC Loads from Rigol, good ones but complicated to use.

Thanks for looking and the comment about the UI of the Rigols  . I've found Globalmediapro as well but without any mention of name & contact address it looks like a super shady business which seems to be located in New Zealand. Also online reviews aren't stellar. I'd rather buy from Aliexpress 

[Martin72]

Aha, you might be right.
Because everything they offer is always in stock...That can't be right, so forget my post before that.
Then the decision would be clear for me.
You can get Korad on every corner, in our country even at Reichelt and Conrad Electronic.
And then would be for me for exactly the reasons you had already mentioned, the Tonghui out.
So if it is to decide between Korad and Tonghui.
Just order, test and if that's nothing, back again and spend a little more money.
As mentioned, the Rigol loads are good, but the menu navigation makes you crazy....

[KungFuJosh]

IME Tonghui makes good quality hardware. However, if you don't buy it directly from them, forget about ANY kind of support. A lot of Tonghui products are rebranded and sold by other parties with the same hardware. If you really want that TH8402A, see if it's sold through any other brands like Sourcetronic.

[Martin72]

If you really want that TH8402A, see if it's sold through any other brands like Sourcetronic.

Already did this....No DC-Loads from Sourcetronic. 

[KungFuJosh]

If you really want that TH8402A, see if it's sold through any other brands like Sourcetronic.

Already did this....No DC-Loads from Sourcetronic. 

I'll mention it to the reps I've been speaking with. 😉

[trp806mo]

I don't have any boot failure on my (home) Siglent but I'm more annoying with its high (normal?) ripple during the regulation.

Regarding Tonghui we wanted to buy one DC load too some years ago but we couldn't do it as they haven't any CE certificate for the office.

@Nctnico, what do you want to know/be checked on the Korad model ?

[nctnico]

I don't have any boot failure on my (home) Siglent but I'm more annoying with its high (normal?) ripple during the regulation.

Regarding Tonghui we wanted to buy one DC load too some years ago but we couldn't do it as they haven't any CE certificate for the office.

@Nctnico, what do you want to know/be checked on the Korad model ?

About the Korad model: I'm interested to know whether it works and if there are any kind of known issues (firmware bugs). I noticed the Korad can be connected to a network. Do you have any experiences to share on how that works?

[Martin72]

but I'm more annoying with its high (normal?) ripple during the regulation.

Depends on the regulation type.

[trp806mo]

ok, I'll upload a short review this week

[nctnico]

but I'm more annoying with its high (normal?) ripple during the regulation.

Depends on the regulation type.

I checked the Siglent SDL1000 manual but can't find any way to adjust loop bandwidth. Then again, a current sink/source has a very high impedance to start with so it is hard to stabilise the voltage using a voltage control loop. If the voltage control loop hasn't been dampened enough, a true current sink will make it oscillate quite easely. In other words, the ripple is likely an effect of the source and load interfering. I have experienced this before using cheaper DC loads.

BTW: I used to have a self built DC load that used transistors as an open-loop (no feedback) near ideal current sink. This thing was handy to test the regulation of power supplies. Unfortunately I blew it up and couldn't find suitable replacement transistor as the transistors I used came from a switching PSU and where custom parts / marked with custom part numbers. In hindsight I got super lucky that these transistors worked at all in a linear application; these transistors must have had an exceptional DC SOA area!

[Martin72]

Would like to see what he meant, is it while a loadstep...

[tautech]

ok, I'll upload a short review this week

Be sure you have the latest FW installed for it to mean anything.

[nctnico]

I've found out Tonghui has a Youtube channel with videos showcasing most of their instruments:
https://www.youtube.com/@changzhoutonghuielectronic3305/videos

Including one that shows a bit about how their DC loads work:

[trp806mo]

I uploaded my review

check the topic Korad KEL2010 / Multicomp MP710771 review

[danils]

Hello there,

I have a Tonghui DC load 8411. When I received it the firmware was very bugged, constant power mode was not working at all. The company answered in half a day and they sent me via email a new, working, firmware.
It still has some problems like the meter showing a DC offset also if it is disconnected (could be a problem of my unit).

About the rest it's a well built unit with some premium components inside (ST MOSFETs), I'd say it's a bargain for the price.

[luudee]

Hi Nico,


I, personally, will never buy anything from Tonghui again.

Sure, the HW may be just fine, but boy, if you ever need a bug fix, or any other type of support, FORGET IT !!!
(As you kow I have their LCR meter, and regret that purchase)


I own an iTech IT8513C+.   A bit more than what you are looking for, but I really like the unit:

Rating: 600W, 120V/120A
About $1200 USD  @AliExpress

iTech also makes smaller (<600W) variation if this is overkill for you ...

The UI takes a bit getting used to, but now I can set it up and am ready for work within seconds!


Cheers,
luudee