Programmable DC load for home lab (2022)? - Page 1
Forum section: electronics / testgear

author: Faranight
author_rank: Unknown
timestamp: November 17, 2022, 08:50:44 am
content: Hey! I'm an electronic enthausiast and I'd like to add a programmable benchtop DC load (with SCPI) to my collection. I'd settle for a device with USB connection, but I'd much prefer a SCPI LAN port since most of my other devices are already LAN-connected. GPIB is not needed. I'll be using it mostly for PV and DIY-power supply testing, but I wouldn't mind some extra features that may come in handy in the future. I mostly work with DC voltages up to 24V so I probably don't need models that go up to 500 volts, 150V is plenty. Though I *would* be interested in a bit higher power rating i.e. 300W.Some models I've been looking at:GW Instek PEL-503-80-50BK Precision 8600B or 8601BRigol DL3021/ASiglent SDL1030X/-EITech 8512G+Maynuo M9712C or M9812Do you have any suggestions which brands/models are best bargin (price vs quality/features)? My budget is about 1000 EUR. I was initially looking at the BK Precision, but hell those are expensive. Then Ilearned that BK models are a redesign/rebrand of ITech... so, should go for ITect instead as its cheaper? Hmm. Maynuo seems to be a clone of ITech/BK by the same engineer according to some posts on the forum. Rigol DL3021 can apparently be unlocked into the DL3021A, not sure about Siglent.I'm looking atITech 8512G+right now because it apparently has a LAN interface. Any comments for/against this model?Thoughts?Thanks in advance.

author: tautech
author_rank: Super Contributor
timestamp: November 17, 2022, 09:21:26 am
content: Quote from: Faranight on November 17, 2022, 08:50:44 amSDL1020X-E can be convinced to be what you need.

author: blackdog
author_rank: Frequent Contributor
timestamp: November 17, 2022, 11:07:05 am
content: Hi,I tested a couple of DC Loads early this year and I still have two here on the workbench now.Actually there are three, I also have a self-built 200-Watt model that is completely analog in design.I still use my analog version the most despite having two modern digital devices.And the reason is that the modern DC Loads I have had in my hands, generate quite a lot of interference signals.The electronic setup of this DC Loads seems to work via PWM which is not optimally filtered.Those modern DC Loads i tested are: theKorad Kel103,Rigol DL3021aand theSiglent SDL1020X.I returned the Siglent because the measurement outputs on the back are a drama, technically very poorly resolved.The Siglent and the Rigol are actually not good for doing measurements on linear power supplies in terms of their dynamic behavior.There is too much noise present on the measurement outputs and also on the Linear Power Supply to be measured when you measure with the oscilloscope.So that is the reason I still often make measurements on Power Supply's with my analog DC Load.When doing measurements on e.g. batteries or accumulators in terms of their capacities, then you will have few problems with the modern factory's devices.Another point to be aware of, read the manual carefully if you are going to modulate the DC Load.The specified rate of current change is hard to get the way you want it.It also depends on the selected current range and still other settings.With an analog DC Load you are always in control of the speed.I use one of my function generators for this and choose the edge steepness as I need it for my measurement without too many limitations of my DC Load.You can, of course, make the controller the most important thing in your consideration, but that,in my opinion, is the electronics in your DC Load must be able to do the measurements properly that you want to do.You can have wonderful control functions for your DC Load, but if it doesn't do what you want, it's a waste of money.Ik hoop this helps,Kind regards,Bram

author: H.O
author_rank: Frequent Contributor
timestamp: November 17, 2022, 11:19:35 am
content: The Maynuo does not have LAN and is not SCPI compatible, it uses MODBUS instead. Fine but a bit strange on a piece of test equipment if you ask me. They have a UART port (not RS232) which is not isolated from the load input so an adapter is needed (buy or DIY) in order to connect to a PC. They seems to work just fine and the PC software is OK. (I have two of these.)TheKorad KEL-103(also sold under other names) is cheap (get ~3 for your budget), does have Ethernet and does speak SCPI but it seems to do it over UDP instead of TCP/IP, even though I have one I have not yet investigated how that works with your normal VISA-libraries like pyVisa and such.I tried to look at the manual 8215G+ but they've looked at some of the so called "A-brands" and put their docs behind a registration wall so I'm not going to bother.

author: Faranight
author_rank: Unknown
timestamp: November 17, 2022, 12:05:43 pm
content: Quote from: H.O on November 17, 2022, 11:19:35 amYeah, I noticed that too. But then again, a quick google search:https://www.itech.sh/uploadfiles/%E7%94%A8%E6%88%B7%E6%89%8B%E5%86%8C/user%20manual/it8500jia/IT8500Gplus%20User%20Manual-EN.pdfEDIT:WTF, ITech? You removed the file literally within some hours of me posting that link? What's wrong with you? I was going to buy your product. Do you*want*me to choose a competitor instead?New link:https://www.manualslib.com/manual/2607203/Itech-It8500gPlus-Series.html

author: BillyO
author_rank: Super Contributor
timestamp: November 17, 2022, 12:49:45 pm
content: The Siglent also has a LAN interface.I ordered one the other day but was .. otherwise occupied .. when the courier got here so missed the delivery.I would have had some fresh perspective on it for you otherwise.Have to go to the depot to pick it up this morning. No 2nd delivery attempts in rural Canada. Couriers get away with murder up here.