Why people here insist on Korad power supply? - Page 1
Forum section: electronics / beginners

author: lordmess
author_rank: Newbie
timestamp: December 29, 2023, 08:57:10 pm
content: I want to buy a new linear power supply. I see many here suggest Korad brand. I watched a 11 year old video from Dave where he tries to review one and ends up a total failure. So I wonder why people here insist on this model? Did the manufacturer changed something over time so dramatically that became a must on low budget stations?

author: tszaboo
author_rank: Super Contributor
timestamp: December 29, 2023, 09:11:20 pm
content: IDK, I had one of these at work, hated it. It had a glitch-y screen, when I was working with power electronics, it gave ma almost a hearth attack. And it's noisy. Try to get a TTI power supply. Or Keithley, Keysight, old Agilent... I have a Rigol at home, great value on that one as well.

author: BeBuLamar
author_rank: Super Contributor
timestamp: December 29, 2023, 09:28:24 pm
content: I bought the Matrix MPS-3605LP for $128 and I liked it a lot. I think it's good value for the money.

author: golden_labels
author_rank: Super Contributor
timestamp: December 29, 2023, 09:29:04 pm
content: I believe the recommendation is not general, but for the cheap equipment segment. In other words: people don’t suggest Korad per se, but in comparison to same models sold under other names.For example Korad analog 3005 models, vs comparable units from WEP, Zhaoxin, Sugeon, NDN, Langwei, RXN, and a bunch of other identical stuff (at best with the front panel redesigned).And the suggestion may not come from Korad being high quality, but predictable quality. I don’t know how current the advice is, but 10–15 years ago Korad was being sold by manysomewhatreputable vendors, while the rest was an eBay lottery.

author: the_cake_is_a_lie
author_rank: Contributor
timestamp: December 30, 2023, 06:20:20 am
content: I don't know but I did internet research (lol) for a long time and bought theX-Tronic PX-70for $130 USD. Came with everything I was looking for and I'm happy. I hate red electronic text for some unexplainable reason so my options were limited.

author: tooki
author_rank: Super Contributor
timestamp: December 30, 2023, 08:24:47 pm
content: Quote from: lordmess on December 29, 2023, 08:57:10 pmNobody “insists” on them. They get recommended a lot because they’re good enough for hobby use, compact, inexpensive, and widely available. The issues in early units have been resolved for years now. They’ll never reach the performance of a Keysight or Keithley, but nobody expects that of a product this cheap.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: January 01, 2024, 07:58:50 am
content: There are Etommens ETM series of power supplies, which are based on same ideology as these Korads, but there are some improvements - Fan is far less noisy and less aggressive, there is a system/calibration menu, from where settings can be changed, like disabling the beep, calibrating readings and so on.So I bought one (ETM-305P) and retired KoradAlso, I have Riden RD6012P, which is also good, but still too hot and noisy. I've fixed that, by replacing the heatsink for output fets, adding heatsink to XL7015, replacing output inductor and replacing the fan with physically larger, but with smaller RPM. But not everyone wants to do all that.

author: Traceless
author_rank: Frequent Contributor
timestamp: January 01, 2024, 10:21:55 am
content: Quote from: lordmess on December 29, 2023, 08:57:10 pmThe original design had a flaw. Dave made a follow-up about an updated revision shortly after.

author: tooki
author_rank: Super Contributor
timestamp: January 01, 2024, 02:27:28 pm
content: Quote from: LinuxHata on January 01, 2024, 07:58:50 am”Ideology”? I didn’t realize that power supplies had belief systems… What do you mean here?The ETM-305P is a switching power supply, unlike the linear Korads that get recommended regularly.The Korads have calibration functions too, and the beep can be turned off.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: January 01, 2024, 04:13:48 pm
content: Ideology means control logic, layout and so on.And some things are improved in Etommens over the Korads in these aspects too, like digit selection and so on.Also, these Etommens are available with linear guts, if needed.

author: tooki
author_rank: Super Contributor
timestamp: January 01, 2024, 04:48:39 pm
content: Quote from: LinuxHata on January 01, 2024, 04:13:48 pmI think “design philosophy”, “UI approach”, or similar would be a much better word than “ideology”, which is very specific and not normally used in product design lingo.

author: liaifat85
author_rank: Regular Contributor
timestamp: January 03, 2024, 03:51:24 pm
content: Here is another review from EEV:

author: rdl
author_rank: Super Contributor
timestamp: January 03, 2024, 04:35:09 pm
content: Korad has always been the cheap option that doesn't suck (too much). There are definitely better power supplies available. However, if you buy a cheap, switching unit masquerading as a "Lab Power Supply", you have my sympathy. I would avoid any thing advertising over 5 amps. They are marketing to the Tim Taylor types. About 99% of the time my 500 mA 24 volt supplies do everything I need.

author: coppice
author_rank: Super Contributor
timestamp: January 03, 2024, 05:19:16 pm
content: If you don't want to spend too much on a power supply, the choices are so limited these days that people keep coming down to the Korad. It doesn't have to be good to be a winner. It just has to not suck too much, and I think after a dodgy start (which Dave documented) they achieved designs that are usable.There are a few reasonable choices for much cheaper simple supplies, like the ones sold as Duratool here in the UK. I have a 3A 0-15V one that cost about 30 pounds. The most negative thing I can say about it is the transformer buzzes a bit, which with small loads, where the fan doesn't make any noise, can be annoying. Why do so many transformers buzz these days? A transformer you could hear was quite rare 20 years ago.

author: tooki
author_rank: Super Contributor
timestamp: January 03, 2024, 05:28:41 pm
content: Quote from: liaifat85 on January 03, 2024, 03:51:24 pmThat‘s not “another” review, it’s the one referred to in the original post. 🙄

author: Siwastaja
author_rank: Super Contributor
timestamp: January 03, 2024, 07:35:13 pm
content: Half of the cheap "lab supplies" are e-waste cons, to the point of just blowing up when used as one normally uses a lab power supply, so it's not surprising to see recommendations for a cheap product which... gets close to specifications and doesn't usually blow up. The bar is just set so low, given the legacy of crappy-beyond-belief supplies.

author: djacobow
author_rank: Super Contributor
timestamp: January 03, 2024, 08:40:28 pm
content: I have several bench PSUs of varying quality and price, including the Korad KA3005P.It's fine.It does basic linear supply stuff and I've had no problems with it. The USB control works and I find that pretty convenient for certain projects.

author: radiolistener
author_rank: Super Contributor
timestamp: January 03, 2024, 10:47:59 pm
content: Korad KA3005 is cheap and pretty precise. And it's linear power supply with low noise, this is the reason why it is so popular.

author: coppice
author_rank: Super Contributor
timestamp: January 03, 2024, 10:52:59 pm
content: A question: are all the supplies which look like the Korad ones actually Korads branded up for various other companies, or are some of them rip-off copies?

author: radiolistener
author_rank: Super Contributor
timestamp: January 04, 2024, 12:16:05 am
content: In theory you can catch some fake Korad, but I didn't hear about such cases

author: rdl
author_rank: Super Contributor
timestamp: January 04, 2024, 06:06:30 am
content: I have seen what look like Korad power supplies being sold (rebranded) under different names. The question I always have is: what compromises have been made in quality and performance to meet the new sellers requirements? If the actual manufacturer's name is on it, I think they are less likely to make bad decisions.

author: Berni
author_rank: Super Contributor
timestamp: January 04, 2024, 06:33:26 am
content: I had a Korad PSU at work (It is actually a Farnell rebranded Tenma or MulticompPro or whatever)Bought one to do some battery testing (Before you ask, yes i used diodes) because i needed a cheap PSU that takes SCPI control for automating the test setup. Had it running for a week or so cycling lead acid batteries.Then hooked up a bigger battery up to it that takes longer to charge up. After about 1 hour of supplying 3A (it was a 5A PSU anyway) the output voltage shoot up and started outputting way too much current. To make things worse this happened while it was running unattended and i caught it a few hours after the failure when checking in trough remote desktop. I could not even stop the current by disabling the PSU, but eventually found out i can stop it by setting it to 1V instead, making the PSU switch to the lowest tap on the transformer. I was about to go call a coworker at 11 at night to go run unplug it before i managed to stop it (I live 50km away from work)So yeah it went back for a refund. But they never ended up shipping it back, so i still have it sitting here in a box. The UI on it is so horrible that nobody here even wants to put in the work to replace the output transistors and take it home.

author: pickle9000
author_rank: Super Contributor
timestamp: January 04, 2024, 07:19:00 am
content: I picked up 5 plus a spare for a test jig about 7 years ago about 4000 hours total on each. I set the voltages hot glued the knobs and they are still kickin'.I purchased them new, are they great? No but ok for my intended purpose. The jig is never unattended when in use. WouldI use it on a regular test bench, no i have better. Would I sell one to a customer? Nope. Would I recommend them? NopeIf I had the same application again in my own shop would I buy them again? Yup.

author: tooki
author_rank: Super Contributor
timestamp: January 04, 2024, 11:40:32 am
content: Quote from: rdl on January 04, 2024, 06:06:30 amAll the rebadges I’ve seen are from big companies (Velleman, Distrelec, Farnell, etc) which want to maintain the reputations of their private-label brands. If anything, they’re more likely to ask forimprovementsthan cost reductions, since as the importer of record, they’re the ones responsible for ensuring compliance with local regulations.

author: tooki
author_rank: Super Contributor
timestamp: January 04, 2024, 11:43:39 am
content: Quote from: radiolistener on January 03, 2024, 10:47:59 pmWell, I think that manufacturers of true low-noise supplies, like Keithley, would disagree with calling it “low-noise”, but it’s certainly more than low enough for the types of things most hobbyists do.(This reminds me, I want to build a little precision supply based on the LT3045. Nowthatwill be a low-noise supply!!!)

author: Berni
author_rank: Super Contributor
timestamp: January 04, 2024, 11:56:09 am
content: Well among the flood of cheap switching lab power supplies onto the market in the past years they are low noise just due to being a linear supply.One of those Blanko PS3010 (a CircuitSpecialists rebrand of that one is often seen in the videos of ElectroBoom, overall pretty popular PSU due to being really cheap for 10A rating) is a huge piece of crap. We also managed to blow up one of these at work and had to RMA it, we killed it due to simply shorting the output. The LCD readouts are slow and inacurate. And worst of all it pumps out so much electrical noise that it might as well be a jammer. I was tracking down a EMI issue on a product with an antenna connected to a spectrum analyzer, then a coworker turned on one of these Blanko PSUs on the other side of the office. Not only did the spectrum analyzer easily pick it up, but it also started constantly beeping because the signal was so large it was overloading the mixer.

author: coppice
author_rank: Super Contributor
timestamp: January 04, 2024, 02:10:44 pm
content: Quote from: tooki on January 04, 2024, 11:40:32 amThis sounds like a good argument, but I'm not sure it holds water any more. So many of the world's really big brand names seem happy to rebrand bought in absolute garbage, or licence out their name and logo to be stamped on any old junk whose maker will put up the licence fee. Even companies whose entire thing was "luxury", like Pierre Cardin, finally ended up with their name on the lowest of the lowest and became a joke.

author: radiolistener
author_rank: Super Contributor
timestamp: January 04, 2024, 02:45:44 pm
content: Quote from: tooki on January 04, 2024, 11:43:39 amYes, it has some little noise from dynamic LED indication. so it cannot fight with true low noise power supplies. But it's noise much-much better than any switching mode power supply, and even better than full analog power supplies like HY1505D. This is what I mean when said "low noise"...

author: zapta
author_rank: Super Contributor
timestamp: January 11, 2024, 05:12:44 pm
content: >> I think “design philosophy”, “UI approach”, or similar would be a much better word than “ideology”, which is very specific and not normally used in product design lingo.I think "better choice" or similar would be a much better choice than "better word". Words are not better than others.

author: tooki
author_rank: Super Contributor
timestamp: January 12, 2024, 09:45:52 pm
content: Quote from: zapta on January 11, 2024, 05:12:44 pmOh please. It’s obvious it’s not a qualitative statement about the sequence of letters/sounds, but of the suitability of the term for the concept being described. The word “better” is frequently used to mean “more suitable for the situation at hand”.

author: Randy222
author_rank: Frequent Contributor
timestamp: January 29, 2024, 03:28:51 pm
content: Is the Matrix stuff about the same as Korad?

author: 5U4GB
author_rank: Super Contributor
timestamp: January 30, 2024, 12:05:24 am
content: Quote from: coppice on January 03, 2024, 10:52:59 pmIt depends on whether you're getting rebrands or knockoffs, if it's something you found on Aliexpress then who knows what you're getting but if it's e.g. a Velleman rebrand I'd expect the real thing. However Digikey sell Korad-branded ones from SRA Soldering Products at around the same price as the Aliexpress ones and they'd be the real thing, so there doesn't seem much point in looking for dubious cheapies from crapvendors.

author: 5U4GB
author_rank: Super Contributor
timestamp: January 30, 2024, 12:11:46 am
content: Quote from: coppice on January 03, 2024, 05:19:16 pmIt's not just "these days", the problem is cheap transformers where they've saved a few cents by not impregnating the laminations. I had two bedside clock radios in the 1980s that both buzzed like a small substation right next to your head until I replaced the transformers with something slightly better than the cheapest junk you could get. Pretty annoying, that's one application where you'd really expect them to avoid transformer buzz.

author: Terry Bites
author_rank: Super Contributor
timestamp: January 30, 2024, 04:19:10 pm
content: they don't

author: radiolistener
author_rank: Super Contributor
timestamp: January 30, 2024, 04:45:36 pm
content: Quote from: coppice on January 03, 2024, 05:19:16 pmmanufacturers save on quality and materials. Most of Chinese transformers have shortened wire on the primary coil, just because these several meters of copper wire cost some cents... It also affects transformer efficiency and max power limit.