Choosing a DC electronic lab for home lab - Page 1
Forum section: electronics / testgear

author: Sariel
author_rank: Regular Contributor
timestamp: November 23, 2023, 06:23:56 pm
content: Hello everyone,I'm currently exploring options to upgrade my lab setup with a DC electronic load. The primary purpose is to assess the performance of linear regulators that I integrate into my designs. I'm on the lookout for a reputable brand offering good-quality DC electronic loads within a budget range of $500 to $2000.The desired specifications include a voltage range of up to 150V (although 40-80V would suffice), and a power range of 50W-150W. Additionally, I need the capability for transient testing (Dynamic). It's essential for the device to feature an output current monitor, and while computer software control would be a nice-to-have, it's not mandatory.I've narrowed down my choices to the following models:IT8500G+ seriesBK Precision Model 8550TTI ld400pIf any of you have hands-on experience with these models, I'd greatly appreciate it if you could share the pros and cons of each, along with your recommendations. Alternatively, if you have suggestions for other reliable devices that fit the criteria, I'm open to exploring those options as well.Thank you in advance for your insights!

author: nctnico
author_rank: Super Contributor
timestamp: November 23, 2023, 06:39:57 pm
content: I'd add the Korad KEL2010 to the list. After long pondering, I settled on this model. But I would have liked to try the Tonghui / BK Precision 8550 load but that wasn't available at the time I wanted to make the purchase.Some interesting discussions here:https://www.eevblog.com/forum/testgear/dc-load-korad-kel2010-or-tonghui-th8402a/msg4969006/#msg4969006

author: Sariel
author_rank: Regular Contributor
timestamp: November 24, 2023, 02:24:48 pm
content: I've conducted additional investigations and gathered more information regarding various electronic testing devices.The TTI LD400p has been reported to exhibit a sluggish loop response and is susceptible to oscillations, impacting its performance negatively.The BK Precision Model 8550, identified as a rebranded device, is known for ripple noise originating from its internal transformer.In light of these findings, I explored alternative options:GW Instek PEL-503-80-50 - $1,300Well-constructed and appears robust.However, lacks a PC control graphical user interface (GUI).BK Precision 8600B - $1,290Compact form factor, addressing the usual depth issue associated with DC loads.Includes PC software control.I am curious if this particular series is a rebrand of another device.IT8512G+ - $876Compact size.Presumably equipped with control software.It's from ITECH, but further information on its performance is needed.I am seeking insights from the community:Among the mentioned brands, which one is considered the best?Does anyone have practical experience with any of these devices?

author: mawyatt
author_rank: Super Contributor
timestamp: November 24, 2023, 06:27:29 pm
content: We have a SDL1020X-E "augmented" to 300W. We've mistreated and overstressed this EL with inductive kick back, reverse polarity, even Over Current (30 amps), Over Voltage (150V), and Over Power (300W) so often, surprised it hadn't given up the "magic smoke" long agoTough little puppy, that's a tribute to the robust design and build. Only real complaint is with the input connectors (lack of Banana type), however there's a $10 simple replacement terminal when we get some time.Best,

author: tautech
author_rank: Super Contributor
timestamp: November 24, 2023, 06:43:39 pm
content: Quote from: mawyatt on November 24, 2023, 06:27:29 pmYep, these:https://www.aliexpress.com/item/32793961677.html?

author: slugrustle
author_rank: Frequent Contributor
timestamp: November 24, 2023, 07:09:17 pm
content: I've had good luck with ITECH equipment generally, both supplies and loads. The ITECH IT6122B lab supplies are incredibly accurate. I've used them extensively for automated testing, and all of the SCPI stuff worked as described in the manual. Almost every other piece of equipment I've used for automated test had at least one quirk, so these were nice. I have an IT8511A+ E-Load and two IT8513B+ E-Loads. While I haven't extensively tested their performance, they have always worked fine when I've used them to test circuit boards, etc.That said, one thing to watch out for is current regulation at low currents. Every E-Load that I've personally used has a lot of current ripple when set to mA-scale currents in CC mode. It's to the point where I've made little unprotected adjustable current sinks with transistors and opamps to do V/I sweeps on linear regulator outputs. More recently, I'm putting together a rheostat set for this kind of purpose.I'm also considering making a dedicated board with low inductance power resistors, MOSFETs, and gate drivers for load step testing of linear regulators because E-Loads have limited slew rates compared to a MOSFET that's switched on hard with a high peak current gate driver.E-Loads are good for middle of the road stuff: Current not too low, slew rate not too fast, etc. Bonus is they can go to very high power depending on the model. I've found them to be the ideal tool for characterizing switching converters, but I have generally found them wanting for characterizing (admittedly small and low power) linear regulators.

author: HKJ
author_rank: Super Contributor
timestamp: November 24, 2023, 07:30:55 pm
content: You have to decide what you want to do: Instant measurements or more wide measurement.If you want the last you need something computer controlled where you can vary the parameters while logging.I am a bit partial to my own software called TestController:EEVBlog thread:https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/Download:https://lygte-info.dk/project/TestControllerIntro%20UK.htmlIt supports a lot of different loads, and other equipment, can step parameters and can show curves and tables of logged result.It supports a lot of equipment:https://lygte-info.dk/project/TestControllerSupportedEquipment%20UK.html

author: nctnico
author_rank: Super Contributor
timestamp: November 24, 2023, 07:37:06 pm
content: Quote from: slugrustle on November 24, 2023, 07:09:17 pmThat seems to be a common issue among various brands due to the transformer being close to the control circuitry. The compact units have no way to correct this as the casing is filled to the brim, but on the big Korad KEL2000 series (for example) it is not difficult to move the transformer further away from the control circuitry resulting in much better ripple behaviour. To the point where it is below 1mA.

author: mawyatt
author_rank: Super Contributor
timestamp: November 24, 2023, 08:17:46 pm
content: Quote from: slugrustle on November 24, 2023, 07:09:17 pmAt low currents for CC this is where SMU might prove more useful than a E-Load. We don't have SMU (yet) and use our GW Instek GPP-4323 as it has a built-in E-Load for lower current use in CC Load Mode. Seems to work well, and not lots of excessive ripple.Best

author: Sariel
author_rank: Regular Contributor
timestamp: November 25, 2023, 07:37:21 am
content: Quote from: tautech on November 24, 2023, 06:43:39 pmIn order to interface the SDL-1020X.Is the following suitable to change the threaded terminal to banana type:Pomona 73086-2https://www.pomonaelectronics.com/products/hardware/terminal-strip-banana-jack-female-10-32-threads

author: Sariel
author_rank: Regular Contributor
timestamp: November 25, 2023, 07:40:31 am
content: Quote from: HKJ on November 24, 2023, 07:30:55 pmThank you. This appears impressive and genuinely versatile. I'll explore it further.However, I have two questions for now:1. Is it possible to connect devices using the USB interface with this program?2. Do I have to install the specific Windows driver for the device before incorporating it into the logging program?

author: tautech
author_rank: Super Contributor
timestamp: November 25, 2023, 08:09:18 am
content: Quote from: Sariel on November 25, 2023, 07:37:21 amNo.SDL1000X studs have M6 threads.

author: HKJ
author_rank: Super Contributor
timestamp: November 25, 2023, 02:28:22 pm
content: Quote from: Sariel on November 25, 2023, 07:40:31 amIf the USB interface creates a virtual com port is works fine.Quote from: Sariel on November 25, 2023, 07:40:31 amYou may need a driver for a virtual serial port, but other than that TestController do not require drivers.TestController is a logging program, but is can do a lot more than log data as you will see if you look through the documentation.Also note that TestController can run on Windows, Linux and Mac.

author: mawyatt
author_rank: Super Contributor
timestamp: November 25, 2023, 06:41:32 pm
content: Quote from: tautech on November 25, 2023, 08:09:18 amWe use these heavy duty spade lugs, they work OK, but not as good as the proper terminal tautech mentioned. Banana plugs into open spade end, we've pumped over 30 amps thru this many times without issue, things get warm tho, including heavy gauge wire!!Best,

author: mawyatt
author_rank: Super Contributor
timestamp: November 25, 2023, 06:46:55 pm
content: Here's what they look like.Best,

author: Veteran68
author_rank: Frequent Contributor
timestamp: November 25, 2023, 08:31:16 pm
content: Quote from: tautech on November 24, 2023, 06:43:39 pmAnother approach with the SDL1020 is this one, if you wanted to keep the original knobs in place.I have both, and honestly think the replacement knobs tautech linked to are just the simplest and easiest option, as they will also work with spade terminals, you don't have to build the adapter board (which costs more with parts), and are just sleeker than adding a board hanging off the front of the instrument.

author: bdeianov
author_rank: Contributor
timestamp: November 25, 2023, 09:25:27 pm
content: Quote from: Sariel on November 23, 2023, 06:23:56 pmI've been considering the Chroma 63000 series for a similar application. They look good on paper and have some unique features like CZ mode. The software is extra $$$ but the protocol is documented in the manual, so adding support to third-party software should be feasible. I too can't find any hands-on experiences with these benchtop models. Chroma has an excellent reputation, but their bread and butter seem to be the larger modular units.https://www.chromaate.com/en/product/dc_electronic_load_63000_series_60

author: Sariel
author_rank: Regular Contributor
timestamp: November 27, 2023, 06:14:11 am
content: Quote from: bdeianov on November 25, 2023, 09:25:27 pmThis DC load looks indeed fantastic on paper and the CZ mode is quite usefull.Is there any trusty seller that sells these Chroma devices in Europe region?

author: jonpaul
author_rank: Super Contributor
timestamp: November 27, 2023, 07:06:55 am
content: No need for fancy and costly electronic loads.Old wirewound power R and rehostats, cost super low.Transient tests use a switch.SIMPLE!We have boxes of them from fractions of ohm to 10K ohms watts 5W>>5KWHam flea markets and silent key estatesj

author: nctnico
author_rank: Super Contributor
timestamp: November 27, 2023, 09:35:08 am
content: Quote from: Sariel on November 27, 2023, 06:14:11 amQuite a few according to Google. Chroma seems to have an office in the Netherlands; give them a call. You'll probably find a local dealer as well.That load looks quite promising indeed. I wish I had seen it before; price wise it is not super expensive. As others I know Chroma for big, automated testing DC loads and didn't knew they have bench top units as well.

author: Warhawk
author_rank: Frequent Contributor
timestamp: November 27, 2023, 09:38:08 am
content: I ended up buying Korad recently. It is good value. Please consider if you want to have VFD display. I've seen too many devices killed by VFDs failures.

author: Sariel
author_rank: Regular Contributor
timestamp: November 28, 2023, 04:07:19 pm
content: If I were to make a decision at this moment, considering both the prices and current stock availability in the market, I'm faced with a choice between:IT8512G+orBK8600BIn the context of being a home DIY designer, which one would you recommend?