Looking for Power Supply Kit to be Assembled - Page 1
Forum section: electronics / beginners

author: Electro Fan
author_rank: Super Contributor
timestamp: November 22, 2020, 09:05:23 pm
content: I'm looking for suggestions for an off-the-shelf linear DC Power Supply kit that requires soldering and assembly - primarily as a learning project. Something adjustable in the range of 15-30 volts and 2-5 amps.The ideal kit would have an enclosure and transformer as well as PCB, meters, and other parts. Soldering and assembly is good but I'd like to avoid fabrication (of the enclosure, etc).The ideal kit configuration would look kind of like a Korad KA3005D with V and I meters (maybe plus a watt meter), OVP and OCP indicators, etc. - but in kit form.I suppose I could take a Korad PS apart and put it back together again but I'd prefer to skip the first step.If you know of any such kit or something similar, please post a link. Thx!

author: Paul Rose
author_rank: Regular Contributor
timestamp: November 22, 2020, 10:15:14 pm
content: Ebay has plenty of partial kits: bring your own transformer, enclosure, meters.Elenco still sells one "full" kit, but it isverylight on features.RD6006 modules are very popular on e-bay/amazon, and enclosure kits are available. You can make a nice supply this way, and you get the fun of putting modules together yourself, but the core module is already done.But I can't recall seeing a "classic" linear full featured supply kit for a long time

author: ledtester
author_rank: Super Contributor
timestamp: November 23, 2020, 12:32:43 am
content: ELV has some kits, like this one:https://de.elv.com/elv-dual-power-supply-dps-5315-komplettbausatz-103190and this single output version:https://de.elv.com/elv-prozessor-schaltnetzteil-sps-5630-komplettbausatz-083399?fs=3776410811&c=256More discussion:https://www.eevblog.com/forum/testgear/please-recommend-a-good-bench-power-supply-for-under-$100/msg259216/#msg259216

author: Electro Fan
author_rank: Super Contributor
timestamp: November 23, 2020, 03:26:24 am
content: Thanks for the suggestions so far.I probably should have mentioned a couple specs: 110V and preferably under $100 or so.I saw this: it's in the ball park, maybe another step up to two.... but this isn't too far off....https://www.instructables.com/DIY-Bench-Power-Supply/Edit:Looks like some EEVers have gone down a similar path - I'm going to check this out:https://www.eevblog.com/forum/beginners/bangood-psu-enhancements/But still very open to other similar or better off-the shelf solder and assemble Linear Power Supply kits that don't require enclosure fabrication, 3D printing, etc.

author: Electro Fan
author_rank: Super Contributor
timestamp: December 04, 2020, 03:11:54 pm
content: Still looking - saw this - it’s pretty close to what I think I’m looking for in case anyone has any thoughts on this design or knows of similar designs in a pre-packaged kit.https://www.instructables.com/DIY-Analog-Variable-Bench-Power-Supply-W-Precision/

author: ledtester
author_rank: Super Contributor
timestamp: December 05, 2020, 07:33:14 am
content: Unfortunately, here is what I see is the problem with power supply kits...The control electronics are cheap enough but...- a transformer is heavy and expensive to ship- a heat sink is heavy and expensive to ship- an enclosure has to be matched to the transformer and heatsink dimensions as well as whatever front panel UI you want- accurate panel meters are not cheap, and I haven't found any that measure high-side current which is what you want for a power supplyand that's why you don't see a lot of complete PS kits.Here are some alternatives to consider...1) Start with an audio amplifier like in these videos:https://youtu.be/_CFIovMkRyghttps://youtu.be/J3N6RX_wAJgYou'll get a transformer, heatsink all in an enclosure with plenty of space to add your own stuff. The hardest part will be redoing the front panel.2) Build a PS using something like the Ruideng/Riden RD6006. A few eevblog-ers are using a linear power supply instead of an SMPS for the main supply, e.g.:https://www.eevblog.com/forum/testgear/ruideng-riden-rd6006-dc-power-supply/msg3354184/#msg3354184https://www.eevblog.com/forum/testgear/ruideng-riden-rd6006-dc-power-supply/msg3008220/?topicseen#msg3008220The RD6006 is very easily incorporated into the enclosure of your choice.3) Just build and test out power supply circuits without worrying about putting them into enclosures. After all, you really can't build one for cheaper than you can buy one, but you can still learn about power supply design by building them up and testing them.Besides the circuits you mentioned, there are a bunch that have been discussed on the forums like this one:https://www.eevblog.com/forum/beginners/lm324-power-supply-with-variable-voltage-and-current/msg3345000/#msg3345000You can also check out the youtube channel "Kasyan TV" for a bunch of low-parts count designs, e.g.:-https://youtu.be/-mnhPGpyZ5U-https://youtu.be/_r3_GjnwI2A-https://youtu.be/uerjfBY3Qo0-https://youtu.be/ZtQA_baEE_4And this one by "TheStuffMade" caught my eye as an attractive project:https://youtu.be/jBtNH1EbU8MA video on some testing you can perform:https://youtu.be/RdT-xWC4h4k

author: Electro Fan
author_rank: Super Contributor
timestamp: December 05, 2020, 07:56:37 pm
content: Quote from: ledtester on December 05, 2020, 07:33:14 amThanks for all the info!I think your assessment regarding the impediments to the Power Supply kit market is correct:1. Weight of transformer can make shipping expensive2. Lack of standardized enclosure, or even any any reasonably PS-appropriate ready-to-go enclosures3. Some complexity in metering and control circuity4. And of course there there are plenty of PS design trade-offsOf all those, I think the lack of ready to go attractive enclosures - or the alternative requirement for mechanical skills and tools beyond electrical skills and tools - might be one of the largest impediments. It's of course hard to design an enclosure unless you know what is going into the enclosure. So, it's a bit of a Catch-22. As you say, this can reduce the project down to building non-enclosed circuits - which is good for educational purposes but is a bit of a drag for users who would like to turn the educational project into a fully useful on-going tool.In my post following this I've added some thoughts on how these challenges might be addressed to provide some supplier(s) with a market opportunity.Back to your post - those are some great videos and other links you posted. I'd encourage anyone trying to gain more understanding and more ideas on power supply designs to check out the info you posted. Each had some good info and inspiration and they all are worth a look.I found this guy (The Post Apocalyptic Inventor) to be super interesting:https://youtu.be/_CFIovMkRygThe guy who repackaged the transistor was pretty nifty too.Another of your links that especially caught my attention was this:https://youtu.be/RdT-xWC4h4k- it compares a DIY PS to two assembled products including the Korad KA3005D. In my opinion, a design similar to the KA3005D is about the right level of performance and features for the semi-DIY kit idea that I have in mind. Theoretically, if Korad offered a KA3005D in kit form and could reduce the price even a few dollars (it sells for about $110 on Amazon) by eliminating the manufacturing and testing costs, I think there would be a market for such a kit that would be both educational and useful beyond the learning experience.In any event, thanks again for your post!

author: Electro Fan
author_rank: Super Contributor
timestamp: December 05, 2020, 08:48:34 pm
content: Having said the above, maybe another challenge is the lack of sufficient market size for Power Supply kits. The overall Power Supply market might be viewed as consisting of a currently dominant segment for off the shelfASSEMBLEDPower Supplies (of which there are already tons to choose from) but also with a second segment for largelyDIYPower SupplyDESIGNS AND LIMITED KITSfor users who want to design and build everything or almost everything to their requirements, and also with a potential third segment described assemi-DIY FULL KITSfor users who would like to build something that comes with a schematic, instructions, and all of the parts - including transformer, enclosure, meters, PCB, etc.Perhaps by the time we get to the semi-DIY FULL KIT segment this segment hasn't been big enough to attract a supplier who can package up a design and all the parts at a price that make sense both for the supplier and the customers.It's just a hunch, but I think with the advent of the maker market, the growing entry level test equipment market, and everything else from interests in basic electronics (both analog and digital) to Arduinos to robots to you name it, it would seem that we might just be on the cusp of there being enough of an addressable market for someone to offer an semi-DIY Power Supply Full Kit.If I was the product manager for such an endeavor I think I'd start with something that offered two versions:1. Full Kit - ~30V, ~5A, constant current and constant voltage modes, OCP, OVP, digital meters for set and actual, transformer, PCB, other parts, enclosure, schematics, 2 youtube instructional videos (one on assembly and one on theory of operations).2. Assembled - same thing just put together.Given that there are a bunch of suppliers who already offer version 2, with a little bit of reverse packaging (unbundling), it would seem that one of the existing suppliers could pretty easily test and address the market for this opportunity. Potentially, this could lead to some other products (maybe a version for most of the test equipment products that users have on their bench). This would perhaps look like Heathkit 2.0 and could be a new market for one of the A, B, or C brand test equipment suppliers. The market for this would include both enthusiasts at home and potentially the school market(s), ie, Junior High School through University.What I think would be distinctive/differentiated (since there are few if any such full power supply kits) and value-added would be the ability to provide a product that could provide both educational value in the assembly process and also competitive features and performance during on-going operational use.If I was Korad I'd offer a KA3005K which would be the KA3005D in a kit form for $69.95 - 79.95 with links to a theory of operations video and an assembly instructional video on youtube - both of which would also be useful marketing materials for Korad in general. I think these would sell well on Amazon. (And frankly, if Korad or some other PS manufacturer doesn't hop on it, Amazon or Walmart might OEM the kits and market them under their house brands.) And the larger opportunity might be to just keep on going down the bench with other Test Equipment products a la Heathkit 2.0. I'm not sure that this makes sense (due to too small a market) for Amazon or the Brand A manufacturers but it might be a growth opportunity for someone like Korad or possibly Siglent, Rigol, etc. To me, it has Korad written all over it.

author: Electro Fan
author_rank: Super Contributor
timestamp: December 19, 2020, 05:04:11 pm
content: For anyone looking for a ton of useful basic power supply building block info very nicely organized in one video check this out:https://youtu.be/IT19dg73nKU

author: CaptDon
author_rank: Super Contributor
timestamp: December 19, 2020, 07:50:19 pm
content: So sad that Heathkit or Eico isn't around anymore!!! My fatherbuilt the Eico VTVM, Tube checker, and a 0-20vdc 0-20amp powersupply. I still have and use all of them in his honor!! I once workedfor J.R.S. Distributors in York Pa USA and we sold tons of Eico kits!!Saw a couple put together with acid core solder.....Ouch!!!! Thestuff was mostly 'experimenter grade' but it was durable and theparts were mostly off-the-shelf replaceable!!! I know a lot of hamsthat became electronic engineers who started off with Eico, Paco,Knight and Heathkit. I am lucky that my formative years were spentin that timeframe with some of the best mentors imaginable!!!!Jim Strauss K3JFL (R.I.P.) was an incredible mentor!!!!

author: Electro Fan
author_rank: Super Contributor
timestamp: December 19, 2020, 11:59:06 pm
content: Quote from: CaptDon on December 19, 2020, 07:50:19 pm+1, Amen

author: Electro Fan
author_rank: Super Contributor
timestamp: January 05, 2021, 09:07:28 pm
content: For anyone finding this thread and wondering how the project progressed, here is a link:https://www.eevblog.com/forum/beginners/question-on-power-supply-diodes/