I think it's time for me to buy a real bench supply, is this a decent one? - Page 1
Forum section: electronics / testgear

author: Red Squirrel
author_rank: Super Contributor
timestamp: November 23, 2021, 05:18:14 am
content: My current PSU is literally a computer PSU I modded with some copper wires sticking out that I can attach crocodile clips to. I think it's time to get a proper one.Looking at this one:https://abra-electronics.com/power-supplies-transformers-adapters/ac-dc-adjustable-power-supplies/ab-5300-1-triple-output-power-supply-0-30v-0-5a-ab-5300-1.htmlOr maybe this one, and getting two:https://abra-electronics.com/test-equipment-tools/test-instruments/power-supplies-ac-dc/abra-low-cost-power-supplies/aps-6005-0-5a-0-60v-switching-dc-power-supply.htmlI actually do want to get more into power electronics and eventually make my own PSUs, either bench ones or just fixed ones with specific purposes in mind, but I will of course want at least one good bench PSU that I can trust.Anyone have any experience with that brand and is it good? I know if I want ultra precision and quality I need to spend way more for a pro grade one but for now I just want something that is decent.

author: ataradov
author_rank: Super Contributor
timestamp: November 23, 2021, 05:38:41 am
content: The second one os complete garbage. Switching and costs more than a good linear. For a single channel have a look at KORAD KA3005P.The first one is pretty generic Chinese supply. Their quality varies depending on a ton of unpredictable factors, but generally they do work. I personally would not use a supply without digital input and lockout against accidental change.

author: TheBay
author_rank: Unknown
timestamp: November 23, 2021, 09:54:25 am
content: As mentioned the KoradKA3005 series are a great little PSU, but be very careful when looking for these as theKD3005 series do not have a switchable output.

author: Andrew_Debbie
author_rank: Frequent Contributor
timestamp: November 23, 2021, 10:33:25 am
content: If youwanta budget switch mode bench supply, look at the Ruideng RD-60xx series. They are 0-60V in 6, 12 and 18A versions. It is inexpensive and compact.The downside is about 100mV pp ripple. The more expensive RD-60xxP versions are about 20mV pp ripple*. The P versions are a buck switcher followed by a linear regulator.Someone here has reverse engineered the supply and offers an alternative firmware.Here --->https://rdtech.aliexpress.com/store/923042* - They spec. ripple measured with a scope set to a 20MHz BW limit.

author: ledtester
author_rank: Super Contributor
timestamp: November 23, 2021, 12:04:47 pm
content: Quote from: Andrew_Debbie on November 23, 2021, 10:33:25 amLook here:https://www.eevblog.com/forum/testgear/ruideng-riden-rd6006-dc-power-supply/875/and here:https://www.eevblog.com/forum/testgear/custom-firmware-reference-document-for-riden-rd60xx-power-supplies/msg3482952/#msg3482952Being in North America I would also look on ebay for used "triple output power supplies" like this one:https://www.ebay.com/itm/363626532975

author: dorkshoei
author_rank: Frequent Contributor
timestamp: November 23, 2021, 03:34:05 pm
content: Quote from: Red Squirrel on November 23, 2021, 05:18:14 amMy strong preference is to purchase items which have published schematics and service info.I don't have an issue with "made in China". My issue is more that the Chinese designs are often not well documented and change fairly quickly.Chinese designs and "trust" don't equate to me. Given what you write above I'd also recommend getting a used BK, HP etc.

author: PaulAm
author_rank: Frequent Contributor
timestamp: November 23, 2021, 04:25:06 pm
content: Look for something in the HP 623x series if you want a triple output supply. These are linear supplies with good specs and often available for cheap. If you need to fix them they will normally require a capacitor or two.I have a 6237b on my bench that I got for $20. Specs are 0-18V @ 1A and +/- 20V at 0.5A, other models have different specs.So it uses analog meters, mehPower Designs also made great power supplies that you can sometimes find cheap.

author: luudee
author_rank: Frequent Contributor
timestamp: November 23, 2021, 04:46:02 pm
content: I am too looking for bench power supply. But I am looking for somethingmore professional, like the R&S NGP814.I am currently using two RD60xx power supplies, which I generally really like, exceptfor the amount of noise they generate. Haven't seen the 'P' versions yet.Also, having 4 outputs is really helpful.Is there something comparable to the R&S NGP814 but slightly cheaper?Thanks,rudi

author: Red Squirrel
author_rank: Super Contributor
timestamp: November 23, 2021, 06:32:32 pm
content: Problem is being in Canada so getting specific models can be hard to find here as we don't have as many online places to buy from. I tend to have to find a place that sells this sort of stuff then go by what they carry. I also don't trust Amazon, too much fake crap. Though I never really considered buying used on ebay, that may be my best bet and more guarantee to get the real thing. That BK one linked may be a good candidate. Even by the time I factor in exchange and shipping etc it ends up cheaper than the one I was looking at. Could not find much info on the Abra one at all so did not know if they were considered decent or not.Is there a place here to get the KA3005? If I can find a reputable site here that sells it, might look at that too.Also when it comes to multi output PSUs is it safe to assume the outputs are isolated from each other or is that hit and miss?

author: ataradov
author_rank: Super Contributor
timestamp: November 23, 2021, 06:35:44 pm
content: Quote from: Red Squirrel on November 23, 2021, 06:32:32 pmCheck on Amazon. I assume there will be vendors there shipping to Canada.

author: AJ3G
author_rank: Regular Contributor
timestamp: November 23, 2021, 06:55:06 pm
content: I seem to recall the RD60XX's can be quitted down by using a linear backend on them. I use 6018's with a very high end switching supply on the backend and the noise seemed to be better than the stock supplies sold as a kit. I have seen some videos (forget who posted them), with a linear supply backend on the RIDENS and the results seemed pretty good. I do know there is some noise which emanates from controller itself. In my case I use it for applications where I the devices it powers are somewhat agnostic to switching noise.RichQuote from: luudee on November 23, 2021, 04:46:02 pm

author: luudee
author_rank: Frequent Contributor
timestamp: November 23, 2021, 07:01:11 pm
content: Quote from: AJ3G on November 23, 2021, 06:55:06 pmThanks Rich, I will wait for the 'P' model to become available and then evaluate them again witha big liner transformer. I think the video you saw is in the RDxxxx thread ...On the other hand the R&S one had the option to time the individual channels, as it is required bymany modern multi supply chips. I'm not sure how to implement that with the RD60xx.rudi

author: mawyatt
author_rank: Super Contributor
timestamp: November 23, 2021, 07:10:34 pm
content: Some interesting discussions here:https://www.eevblog.com/forum/testgear/gw-instek-psu-calibration/Please note the post and references by Momchilo and Hydron and the measurements made on the GPP-4323https://www.eevblog.com/forum/testgear/gw-instek-gpp-3323-psu-fan-noise-on-idle/Best,

author: pqass
author_rank: Super Contributor
timestamp: November 23, 2021, 07:19:53 pm
content: I've bought power supplies from the first two eBay.ca sellers. They just charged HST+shipping. No customs/duty or other issues. The third vendor seems to be a bit pricier but has much more inventory.https://www.ebay.ca/str/selecttesthttps://www.ebay.ca/str/electronicdistributorsintlhttps://www.ebay.ca/str/torontosurplusscientificSpecifically, have a look at:-https://www.ebay.ca/itm/373078786097which looks similar to your first link but is missing an easy to replace knob.-https://www.ebay.ca/itm/324852729557which could use a bit of cleanup but produces quiet output (I have four of this series). The schematics are available but the GPIB card is undocumented as far as I can tell. I think it's still a good stand-alone PS.They also have HP gear too.

author: dorkshoei
author_rank: Frequent Contributor
timestamp: November 23, 2021, 07:23:09 pm
content: Quote from: pqass on November 23, 2021, 07:19:53 pmThe OP might want to tryhttps://www.sphere.bc.ca/test/power.html#catalog-- the owner is active on the HP group and they have good prices.I've bought stuff from Martin @select-test before. He's a nice guy. They have a website also.http://www.select-test.com/

author: AJ3G
author_rank: Regular Contributor
timestamp: November 23, 2021, 07:40:49 pm
content: Hi Rudi:Yes, sequencing may pose a bit of a challenge for the RIDENS. There may be a way to implement the sequencing, but it would not be as straightforward as the R&S.. I think you are right about where I ascertained the information on Linear vs. Switching backends for the RIDEN's. I remember it was very well done, and thorough. If I recall there were many videos from the author on the topic. I used them when making making my own backend for the controllers.RichQuote from: luudee on November 23, 2021, 07:01:11 pm

author: ledtester
author_rank: Super Contributor
timestamp: November 23, 2021, 08:24:40 pm
content: Quote from: Red Squirrel on November 23, 2021, 06:32:32 pmGenerally that is the case. The only exception I am aware of is the Rigol DP800 series where the 5V output shares ground with one ofg the 30V outputs.

author: Red Squirrel
author_rank: Super Contributor
timestamp: November 23, 2021, 11:39:46 pm
content: Thanks everyone for info, this one linked may fit the bill so think I will go with that one:https://www.ebay.ca/itm/324852729557I like that it's in Canada so I don't need to deal with exchange or customs and it's even been calibrated according to sticker.

author: pqass
author_rank: Super Contributor
timestamp: November 24, 2021, 02:21:59 am
content: Quote from: Red Squirrel on November 23, 2021, 11:39:46 pmGood choice. The XT-series were designed in the mid-'80s and are badged Xantrex/Sorensen/Ametek and still sold new today. Also very repairable; all chips socketed and jellybean through-hole parts.Link to the hi-res schematic:https://www.eevblog.com/forum/repair/sorensen-xantrex-xt-15-4-power-supply-repair-calibration/Link to the service manual:https://xdevs.com/doc/SORENSEN/XANTREX%20XT%2060%20WATT%20SERIES.pdfMore docs here (scroll-down to XANTREX XT):https://xdevs.com/doc/SORENSEN/However, the GPIB card in your '80s vintage PS appears to be one based on a single MCS-48 architecture (National NS87P50) MCU. You'll see other XT-series PSs having a white RJ45 below the IEEE488 but that's the next generation card that has two 68HC11 MCUs. All the documentation I've found is for the dual MCU GPIB card. The most I've gotten out of my early-model GPIB card is "OKAY". I've dumped the ROM on my XT7-6 to a hex file and ran it through a disassembler hoping to find some obvious strings but no luck. Life is too short to actually understand what's going on.