EEVblog #1023 - Rigol DL3021 Electronic Load Teardown

[Rbastler]

I have to admit that my confidence in Rigol is severely shaken, the scope i have is nice but clearly they went bananas over scope design as it's the first and most desired product, but can they make anything else properly? maybe not.

I do like the DP832 and DM3068 very much, no issues or complaints so far.
I wound'nt say may confidence in Rigol is severely shaken but it certantly made me think again, if that e-load is good for my purposes and if Rigol is the only real good deal here. I think it still is though, because there arent valid alternatives for me, but I dont have the good feeling when thinking of buying it, I had with other Rigol gear.

[Monkeh]

The heat sink temperature at some 80 C is not such a disaster - they may fix it in future versions. Also the 240 V volts in Australia give the regulator is little more stress than 230 V in Europe.

Maximum AC voltage today     : 250.70 volts

[mcinque]

For me Rigol has simply missed price vs specs. If the load had the same price/specs as the dp832 (even with his issues) they would have take the market for hobbists/entry level gear. Instead, they made something that isn't good enough and, most of all, it's overpriced. It can't beat Maynuo for me, both for hardware and software.

[SharpEars]

The cheap obsolete $0.60 Chinese fake MOSFETs they use in the electronic load, IRFP250n are not even characterized for DC operation or even operation beyond a 10 ms pulse, correct me if I am wrong here.

Good luck with the longevity aspect of this electronic load, since we don't even know if they are operating the MOSFETs in their safe operating area or if there even is a safe DC operating area:



They should have spent several dollars per MOSFET, used fewer of them, and gotten MOSFETs that are characterized to DC like the Linear L2 series from IXYS.

For example, the IXYS IXTP80N075L2-ND go for $3.20 in quantity (probably much less B2B) and are characterized all the way down to DC (not to mention have better characteristics being also 30 Amp MOSFETS):

[tszaboo]

The cheap obsolete $0.60 Chinese fake MOSFETs they use in the electronic load, IRFP250n are not even characterized for DC operation or even operation beyond a 10 ms pulse, correct me if I am wrong here.

This was only discussed for 4 pages now.

[schopi68]

For me Rigol has simply missed price vs specs. If the load had the same price/specs as the dp832 (even with his issues) they would have take the market for hobbists/entry level gear. Instead, they made something that isn't good enough and, most of all, it's overpriced. It can't beat Maynuo for me, both for hardware and software.

Hardware on the Maynuo is something i would not throw into the discussion. In my opinion the Maynuo is 20 years back. No isolation from the rear panels, no specs about the maximum isolation voltages above ground, no interfaces more than RS232... unspecified slew-rates and overshot problems.

[ass20]

hi
 what is adc and dac used in rigol load ?

[mcinque]

Hardware on the Maynuo is something i would not throw into the discussion. In my opinion the Maynuo is 20 years back. No isolation from the rear panels, no specs about the maximum isolation voltages above ground, no interfaces more than RS232... unspecified slew-rates and overshot problems.

So Maynuo is not the perfect load and has his limits (so the BK ones and other clones), but does this change anything about the Rigol as acceptable load with all the issues we're discussing here?

[Rbastler]

For me Rigol has simply missed price vs specs. If the load had the same price/specs as the dp832 (even with his issues) they would have take the market for hobbists/entry level gear. Instead, they made something that isn't good enough and, most of all, it's overpriced. It can't beat Maynuo for me, both for hardware and software.

Hardware on the Maynuo is something i would not throw into the discussion. In my opinion the Maynuo is 20 years back. No isolation from the rear panels, no specs about the maximum isolation voltages above ground, no interfaces more than RS232... unspecified slew-rates and overshot problems.

But you pay way less for a Maynuo, than a comparable "name" brand. So I'd say thats part for the cause. I got no issues with it. Can't expect everything for 275€ delivered. (Maynuo 9710 from a Chinese seller with German Stock).

[schopi68]

Hardware on the Maynuo is something i would not throw into the discussion. In my opinion the Maynuo is 20 years back. No isolation from the rear panels, no specs about the maximum isolation voltages above ground, no interfaces more than RS232... unspecified slew-rates and overshot problems.

But you pay way less for a Maynuo, than a comparable "name" brand. So I'd say thats part for the cause. I got no issues with it. Can't expect everything for 275€ delivered. (Maynuo 9710 from a Chinese seller with German Stock).
[/quote]

When buying in the chinese market the DL3021 has a list-price of 388€ - not such a big difference.

And if you are going to the Maynuo M98-Series you will pay much more. A M9812 will cost around 500€.

[Wolfgang]

Hi Dave,

I saw your review and it made me reconsider my idea to get one of those. I asked RIGOL about what they think about your findings and if there were any plans to fix some of them and what timeframe would be needed for that.
When I remember your review of the DP832A they reacted to your critique and redesigned and improved the instrument, so why not the same here ?

The reply by RIGOL was that they are not OK with your conclusions, and they wrote you a mail (not published).

My questions:
- will there be a follow-up on the issues described in your video ?
- Are there new facts I need to consider ?

Best regards
  Wolfgang

[schopi68]

Hmm... interesting to see (that the do react sometimes).
I made the youtube-video where i showed the oscillation of the DL3021A some time ago primarily to send it to the Rigol-Support. Up to now i did not even get a response from them about the situation shown there (what has been the main reason for me to publish this video some time later here to the public).

[Houseman]

Hi folks.
I have read all your comments and are astonished how much once can learn from different points of view.
By the way a breaking question out from investigation.
Where can I find those beefy red and black cables (tagged I partially see BK precision) shown in minute: 28:30?
Any help would be very appreciated.
And thanks all.
My respect
Steve

[sebastos08]

Hi all,
depending on this review, I decided to buy this item.
I currently own a oscillo, signal generator, DC power supply, dmm.. All in the brand Rigol.

I am globally very satisfied with their products, despite some software bug.
I must say that Dave's reviews weighed a lot in my decisions.

 and especially thanks to Dave's for his "riglol" utility ... about this, is Dave considering completing his great utility to crack access to the options ..?

[TT_ZX]

Where can I find those beefy red and black cables (tagged I partially see BK precision) shown in minute: 28:30?
Any help would be very appreciated.
And thanks all.
My respect
Steve

Are these what you are looking for?
https://www.tequipment.net/BK/TLPWR1/Misc-Test-Leads/

[Houseman]

Yep!!!
They Are!
I could not find them on the net even searching for BK, the initials I was lurking from the video..
Thanks alot, Pal.

Regards

[Smokey]

ppppplease don't spend $75 USD on basic power hookup cables with fork terminals on the ends....  That would make me cry inside. 
If you have to... absolutely have to... I know some other cables that should be right up your alley....


http://www.audiolab.com/audioquest-diamond-hdmi-digital-audio-video-cable-with-ethernet/?utm_medium=googleshopping&utm_source=bc&attributes=eyIxMTM4MiI6Ijk3NTYifQ%3D%3D&gclid=EAIaIQobChMI0JqM3ZOV2AIVBrjACh2ZrA1-EAQYAiABEgIHffD_BwE

[Mr. Scram]

60A HMDI cables would actually be pretty cool. Useless, yet cool.

[Decoman]

So in the video there can be seen a Rigol motto printed on the board inside the unit saying "Innovation or nothing". This reminds me of this technologist that showed up to testify in US congress re. internet/security in a hearing not too long ago, but as I remember it seemed to me like something deceptive when the conversation revolved around this nonsensical topic simply named "innovation". There was no explanation given as to what "innovation" would mean, and this more or less well known technologist in this regard ended up parroting the expressed sentiment of a public official on the other side of the panel in that congress hearing, both simply advocated so called "innovation" without explaining what that meant. As I remember it, none of the two at the hearing even bothered to discuss or elaborate on if the meaning of 'innovation' then could perchance come to mean less charming things like developing surveillance software or for espionage, or other similar types of products, and knowing how like businesses keep making new versions of a product to replace old ones for the purpose of selling something perceived as "new" onto a market, I can't help but think that "innovation" is a concept with unclear meaning at best.

[sstepane]

Hi,

Is any Dl3021 owner in here? I would like to ask what are update refresh options available for monitoring the current, for example?
Can't seem to find anything about it in manual. From video it looks like 1 update/sec, but that's quite slow. Are there any in-device or remote software options on that?
Thanks in advance!

[policeman0077]

Any one knows whats the sampling rate when you use record function?

[Wolfgang]

Hi,

after the appropriate cooloff period of almost a year RIGOL seems to have fixed some issues found out by Dave. I tested one now for a week and it operformed without any quirks, so I bought a 200W A version and I like it so far.

The A version is a bit expensive but you can negotiate a bit so its OK in the end.

Best regards
   Wolfgang

[sirhcel]

They could definitely sell/include a small adapter PCB though, to convert the huge terminals to standard banana jacks. Would be easy for someone to design one.

I was fiddling around with connecting test leads to this load which was pretty annoying. I found some adapters for other binding post distances but none for 39 mm distance here. So finally I ended up with building my own adapters: https://github.com/sirhcel/dl3000-adapters You could order the PCBs directly from OSH Park for convenience.

Best regards,

Christian

[uer166]

One datapoint: I just blew up my DL3021 after using it with a 155V input at 200W. Yes, slightly over-limit, but I didn't expect it to fail short on the pass FET almost immediately. It sinks about 7A at 1.4V permanently now, very disappointing.

[joeyjoejoe]

I was fiddling around with connecting test leads to this load which was pretty annoying. I found some adapters for other binding post distances but none for 39 mm distance here. So finally I ended up with building my own adapters: https://github.com/sirhcel/dl3000-adapters You could order the PCBs directly from OSH Park for convenience.

Awesome, just ordered a DL. I will probably design a similar board as you but with connectors I can source in Canada a little easier, and post here when done.