KORAD KA3005P - $99 USD 30V, 5A DC Programmable PS - Page 1
Forum section: electronics / general

author: george graves
author_rank: Super Contributor
timestamp: June 24, 2012, 11:28:22 am
content: I didn't see this one discussed yet (or I missed it - my apology)Would love your thoughts on this one....I'm ready to buy if it's deemed "decent" I guess.Has anyone have any info on this new(?) PS? Seems like a steal for the money. $99 on amazon.Quote

author: Hideki
author_rank: Frequent Contributor
timestamp: June 24, 2012, 01:59:36 pm
content: It appears to be yet another variation of the Vantek, Yori, Quakko (etc.) power supply but with a slightly redesigned front panel.https://www.eevblog.com/forum/product-reviews-photos-and-discussion/vantek-dps-3305p-32v5a160w-programmable-dc-power-supply/As sold here:http://www.precisegauge.com/index.php?main_page=product_info&cPath=59&products_id=434I guess it follows the Chinese tradition of designing something once, then creating a dozen copies/variations/clones that look almost the same outside, but often have huge differences inside to save money.Compared to the Vantek, Korad has lost one preset button (but the buttons are larger), uses a smaller transformer (and not a toroid) and generally seems to have less components inside.

author: EEVblog
author_rank: Unknown
timestamp: July 17, 2012, 01:20:54 am
content: I now have one. Expect a teardown and review shortly.Dave.

author: David_AVD
author_rank: Super Contributor
timestamp: July 17, 2012, 02:28:53 am
content: Cool. I've been thinking of buying one of these for my automated testing system.They go on eBay for about AUD $170 delivered and at Trio Smartcal for$245$199 + GST (must have just dropped) plus delivery. I like the idea of local support and warranty.I don't need super duper precision myself so would be interested to see if they are reasonable for the price.

author: EEVblog
author_rank: Unknown
timestamp: July 17, 2012, 03:41:08 am
content: Quote from: David_AVD on July 17, 2012, 02:28:53 amYes, Triosmartcal just dropped the price to AU$199+GST.Shipping is not cheap to Oz, and they didn't buy hundreds at first.I also have it on good authority that the Amazon supplier is basically selling at-cost. So if you want that US$99 price you'd better grab it now. And so I get a cut of that, be sure to use this link ;->http://www.amazon.com/gp/product/B0085QLNFM/ref=as_li_ss_tl?ie=UTF8&tag=ee04-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B0085QLNFMBTW, the transformer is not switchable, so no good Oz people buying from the US.Dave.

author: EEVblog
author_rank: Unknown
timestamp: July 17, 2012, 03:46:17 am
content: Teardown photos here:http://www.flickr.com/photos/eevblog/sets/72157630614097948/It's certainly not bad at all for the price.Yes, the USB/serial is isolated from the output.Dave.

author: Monkeh
author_rank: Super Contributor
timestamp: July 17, 2012, 03:58:07 am
content: The PCBs look absolutely filthy. I doubt I could keep the toothbrush and bottle of IPA away from that for long.E: Oh, come on, that earth connection on the USB socket is awful.

author: EEVblog
author_rank: Unknown
timestamp: July 17, 2012, 04:00:16 am
content: Quote from: Monkeh on July 17, 2012, 03:58:07 amPar for the course in this style instrument really.Dave.

author: george graves
author_rank: Super Contributor
timestamp: July 17, 2012, 05:08:34 am
content: What's the cause of the filth on the boards? Only a partial flux cleaning? Looks more like it was the boat's anchor, rather than it's cargo!Can't wait for the video review Dave! You the man!George Graves

author: calin
author_rank: Regular Contributor
timestamp: July 17, 2012, 06:55:28 am
content: Funny .. I was just looking at one on Amazon then I searched for a review (KORAD-PROGRAMMABLE review) .. Google has got this thread in third place in the results.I agree , that PCB looks like it was sunk at the bottom of the sea. Dave, are you sure they got that to Australia on the boat or they just dragged the thing through water from China all the way down to Sidney

author: EEVblog
author_rank: Unknown
timestamp: July 17, 2012, 08:03:03 am
content: UPDATE!My unit DIED during the reviewHorrible, just horrible.More to come, gotta head home...Dave.

author: dda
author_rank: Contributor
timestamp: July 17, 2012, 08:29:06 am
content: The best kind of review. I can't wait. This just doubled the length of the video.

author: EEVblog
author_rank: Unknown
timestamp: July 17, 2012, 09:00:21 am
content: Quote from: dda on July 17, 2012, 08:29:06 amI'm thinking about just skipping the review part and going straight to the horror show!Dave.

author: David_AVD
author_rank: Super Contributor
timestamp: July 17, 2012, 09:01:35 am
content: Sounds like I should strike that model / brand as a potential purchase.

author: george graves
author_rank: Super Contributor
timestamp: July 17, 2012, 09:48:25 am
content: I'd still like to see the review in case it was just a bad unit.

author: amyk
author_rank: Super Contributor
timestamp: July 17, 2012, 10:09:51 am
content: Do they really think scratching out the part# of the MCU is going to make it any less easy to identify?QFP48, USB interface... ATUCxxL4U matches the pinout particularly with the USB DM/DP pair's location and the power/ground pins

author: saturation
author_rank: Super Contributor
timestamp: July 17, 2012, 11:35:19 am
content: This is a glitch just waiting to happen, and it did. Maybe that's why its being sold nearly at cost, its probably been reported to have high failure rates.Tear downs are so helpful, lack of attention to detail inside is a clear sign of poor workmanship, and a good indicator for premature failure later on. Its not just cleanliness, the soldering has many cold joints.Don't judge a book by its cover but by its contents.BTW, cheapo Chinese PSU aren't all bad, at least the Mastech have better build quality, and likewise, better performance thereafter.As a warning, a recent check of Mastech sitehttp://www.mastechpowersupply.com/... shows the supplies are now being branded as Volteq, if this means the source has a different supplier or its Mastech's way of differentiating its version means the quality these units are again questionable without another tear down.

author: AlphZeta
author_rank: Regular Contributor
timestamp: July 17, 2012, 03:43:39 pm
content: Can't wait to see what went wrong with Dave's unit

author: SeanB
author_rank: Super Contributor
timestamp: July 17, 2012, 04:05:51 pm
content: Dave can post it to me, I will fix it, or Widlerise it.

author: Dark Prognosis
author_rank: Regular Contributor
timestamp: July 17, 2012, 06:01:21 pm
content: Korad KA3005P is price fixed all over the damn place as it is $99-99.99 every where.

author: IanB
author_rank: Super Contributor
timestamp: July 17, 2012, 06:52:31 pm
content: So I wonder if this is actually a "product", or whether perhaps someone speculatively made a batch of a few thousands of them (tens of? hundreds of?) and just put them out there to see if they could shift them? And when they're gone they're gone...

author: codeboy2k
author_rank: Super Contributor
timestamp: July 17, 2012, 08:20:14 pm
content: what's with that 24-bit DAC made up of 5% 0603's ? The DC errors (DNL, INL, offset, fullscale) must totally blow, as well as the tempco. Who knows how it behaves when you are using it on a hot sunny day on the beach in Tahiti.

author: Bored@Work
author_rank: Super Contributor
timestamp: July 17, 2012, 08:44:28 pm
content: Quote from: IanB on July 17, 2012, 06:52:31 pmOr they swept the floor, found some more spare parts in a closet, got some surplus stuff on the grey market, and hired the guy who designs the toys for the Kinder Eggs1in his day job to make the leftovers into a power supply.---1. Illegal in the US since 1843 (or so).

author: Erwin Ried
author_rank: Regular Contributor
timestamp: July 17, 2012, 09:31:32 pm
content: Dave is so severe with cheap stuff, at the end I don't expect a wonderful device if I sort them by price when buyingI have an atten psu, solder station, rework station and I am pretty happy with them!

author: grenert
author_rank: Frequent Contributor
timestamp: July 18, 2012, 12:53:47 am
content: Quote from: Bored@Work on July 17, 2012, 08:44:28 pmThe parts in that thing look so beat up, that my first thought was that it's a special "green" meter made from reclaimed components from discarded PCBs!

author: EEVblog
author_rank: Unknown
timestamp: July 18, 2012, 12:57:20 am
content: Quote from: Erwin Ried on July 17, 2012, 09:31:32 pmI think I'm pretty fair.I use a cheapo hot air station, cheapo pliers, and the occasional cheapo mulitmeter.This supply was looking like good value, until it blew upDave.

author: EEVblog
author_rank: Unknown
timestamp: July 18, 2012, 12:58:44 am
content: Quote from: Dark Prognosis on July 17, 2012, 06:01:21 pmCan you post links?All I could find was that one Amazon seller.Dave.

author: Monkeh
author_rank: Super Contributor
timestamp: July 18, 2012, 12:59:39 am
content: Quote from: EEVblog on July 18, 2012, 12:57:20 amHow did it blow?

author: AlphZeta
author_rank: Regular Contributor
timestamp: July 18, 2012, 01:01:59 am
content: Hi Dave,It appears thathttp://sra-solder.com/is the seller (same seller on Amazon).

author: pickle9000
author_rank: Super Contributor
timestamp: July 18, 2012, 01:05:42 am
content: Ebay, same sellerhttp://www.ebay.ca/itm/KORAD-PROGRAMMABLE-PRECISION-VARIABLE-30V-5A-DC-POWER-SUPPLY-DIGITAL-LAB-GRADE-/110888868115?pt=BI_Electrical_Equipment_Tools&hash=item19d17dd913

author: Rising Edge
author_rank: Newbie
timestamp: July 18, 2012, 07:09:22 pm
content: Hi,i found a possible danger spot in the unit from teardown,What can happen, when that shunt above the mains switch becomes too hot? Maybe during normal 5A operation or in addition to an "Error" like in Dave's self-destroyed sample?Maybe it will only become warm - but when it becomes really hot......and the shunt "moves" in the melting solderjoints on the board, or the230V cables below that shunt come in contact with that shunt, because of production tolerances -...the output voltage won't be limited to 31V anymore - the may rise quickly to 230V to ground-pot'!...only thoughtsByeIngo

author: charithjperera
author_rank: Newbie
timestamp: July 19, 2012, 01:02:14 pm
content: I'd be very interested on hearing about what went wrong with this unit. I have had another unit fail in an almost identical manner.

author: Monkeh
author_rank: Super Contributor
timestamp: July 19, 2012, 01:11:12 pm
content: Quote from: charithjperera on July 19, 2012, 01:02:14 pmAccording to KORAD, bad power transistors.

author: mazy
author_rank: Newbie
timestamp: July 20, 2012, 09:56:44 am
content: Reseller Polandhttp://www.hotair.pl/pl/sklep/zasilacze-laboratoryjne/zasilacz-laboratoryjny-pojedynczy-30v-5a-dc-ka3005d-korad.html?keyword=korad68 Euro - Korad KA3005D30 Euro Ship---------------98 Euro Total

author: amspire
author_rank: Super Contributor
timestamp: July 23, 2012, 04:42:12 am
content: Quote from: Monkeh on July 19, 2012, 01:11:12 pmThe heatsinking looks very marginal. A fan cooled supply likes this with a minimal heatsink size does need thermal limiting on the power transistors, but I suspect that is one thing that would go in the cost cutting exercise.If they used MOSFETs, many of the low voltage high power mosfets are not rated for 5A continuous operation in linear mode. It is an easy error for a designer to make to assume that a pair of 60A MOSFETs can handle 5A in linear mode easily, but this is often not the case. The cure will be to choose properly rated MOSFETs.If you have set the supply to 5A, 30V, and you drag the output voltage down to 5V, I wonder if the relays select the lowest transformer voltage, or if it stays on the highest transformer voltage output and cooks the power transistors.If the design is sound, the next most likely causes of infant mortality will be faulty antistatic component and board handling at the manufacturer, of the component suppliers,or the use of counterfeit components.Richard.

author: MBY
author_rank: Regular Contributor
timestamp: July 23, 2012, 02:24:23 pm
content: I have followed this "affair" with great interest. The power transistors seems the culprit alright, but there is something else bothering me. Dave got like 56 volts out of it when the set-point was lower. Even with blown power FETs/NPNs/whatever, yes, even with them replaced by wire, the control loop should switch in the right transformer taps for the set-point. So, with a setting of say 3 volts and a load of several amps, there should be no way the highest taps on the transformer being used. Something else must have broke. Maybe this thing broke the transistors as well? A failure to switch in the right taps for the setting (or pull down by the load) will put almost any transistor out of SOA, even if proper speced transistor is used. May I suggest another line of inquiry: something in the control loop put those transistors out of SOA. Maybe something as easy as a bad solder joint. A sensible design puts the lowest tap in place if both relays is non-energized. I wonder how this is done in Korads design? Another thing I don't like at all is the soft output on/off. It should be a relay or at the very least separated from the drive transistors!The method of using multiple taps on a transformer and comparators driving relays to switch in suitable taps is an old one and is a alternative to a switching pre-regulator. This method is proven and common so I am really suspicious of a PSU screwing it up. Strangely tho, I want one! As soon as this matter is cleared and we know how the control loop is working, there seems to be plenty of potential to do own mods, like overspecing the power transistors, build a better heat sink, improve the discrete 0603 DAC, adding a more precision reference, and so on. If I can find one shipped to Sweden for anything near $99 I would be very happy!

author: SeanB
author_rank: Super Contributor
timestamp: July 23, 2012, 03:22:18 pm
content: I would like one too, I just would improve the cooling. A first would be to replace the spacers on the fan to the heatsink with ones that are at least three times as long, as well as drill the heatsink full of 10mm holes to improve the airflow through the unit. Other than that, clean the board, add a second set of output posts and add some display dimming ( not a fan of dim displays or ones you can read across the street in daylight either) along with moving the capacitor to the bottom of the case, and connecting with thick wire to the board.

author: asbokid
author_rank: Regular Contributor
timestamp: July 26, 2012, 09:12:24 pm
content: Quote from: MBY on July 23, 2012, 02:24:23 pm310CNY (US$48.50) athttp://item.taobao.com/item.htm?id=13562018132China Post SAL (airmail) Shipping (5kg) to SE = 339.8CNY (US$53.20)(plus local taxes)EDIT:Sorry, not the RS232-programmable model.

author: poorchava
author_rank: Super Contributor
timestamp: July 26, 2012, 10:36:01 pm
content: QuoteYeah, I've found that few days ago. What makes whole pricing ridiculous is not that shipping is extraordinarily expensive, but rather PSU is cheap. I guess it seems that in terms of expedited shipping like DHL, UPS etc 30-40 euro is normal price tag for international shipping. And Polish electronic equipment dealers very rarely agree to ship relatively fragile equipment with regular post service - it's a common sense in my 'lovely' country that postal office employees handle packages with no regard to what they contain (including kicking, beating with baseball bat to fit in the compartment in the van etc - there are videos of that over the net).Maybe it will make you feel better if i tell you that ordering anything from mouser, digikey etc involves similar shipping fee. It's not uncommon for few people to gather their 'shopping lists' and then make a single order to share shipping costs.If there was any way of telling good transistor boards apart from bad ones (like part or batch number), i could call/email them and ask about such details. Dunno if they would be willing to provide those, though.

author: slburris
author_rank: Frequent Contributor
timestamp: July 27, 2012, 04:08:51 am
content: Not to brag (well, maybe a little), Dave's review sent me to Ebay to look forprogrammable power supplies. For $77 total (including free shipping), I pickedup this little supply. A Tektronix PS2510G 36V 3.5A programmable powersupply.Not quite as much power as this Korad, but I think it will work better :-)Is it perfect? No, it needs to be cleaned, and it looks like the decimal pointdoesn't work on the volts display. The keyboard looks like it has come loosein the lower left corner. But these are all quite fixable items.As you can see from the photo, my trusty Fluke 87-V says the voltage isspot on. I'll have to take it apart and post some photos.Scott

author: grenert
author_rank: Frequent Contributor
timestamp: July 27, 2012, 05:50:28 am
content: I think that Tek's power supplies (and other stuff like function generators and counters) of that era were made by Instek. Yours looks like this one:http://www.rapidonline.com/Electrical-Power/GW-Instek-PPS-3635-GPIB-Programmable-Linear-DC-Power-Supply-517311It sells for a lot more than you paid

author: slburris
author_rank: Frequent Contributor
timestamp: July 27, 2012, 02:32:00 pm
content: Fascinating. I thought this unit dated from the early 90s. Was Tek reallydoing OEM deals with Instek back then? I'll be real curious to see whatthe build quality is when I take it apart.It's *got* to be better than the Korad.As for the price, yes, no one else seems to be selling one at nearly thatprice. There's one available right now for $1100, ouch!Just shows you can get still get some decent buys on test equipment, ifyou are willing to be patient. I wasn't patient -- I just lucked into this one :-)Scott

author: T4P
author_rank: Super Contributor
timestamp: July 27, 2012, 03:23:52 pm
content: http://singapore.rs-online.com/web/p/power-supplies/4461601/Also made by GW InstekSame one dave has on his benchQuote from: slburris on July 27, 2012, 02:32:00 pmGW Instek is known for being good in quality while not costing a bomb before rigol came in, they are from taiwan just so ya 'know

author: ivan747
author_rank: Super Contributor
timestamp: July 27, 2012, 04:22:58 pm
content: Quote from: amspire on July 23, 2012, 04:42:12 amThe right way to determine the maximum allowed current in linear mode is calculating the power dissipation and making sure it doesn't exceed the ratings right?

author: GnatGoSplat
author_rank: Regular Contributor
timestamp: July 27, 2012, 09:05:46 pm
content: Quote from: slburris on July 27, 2012, 02:32:00 pmWhoah, seller originally wanted $500 Buy It Now for it. You definitely got lucky, poor seller!

author: ProBang
author_rank: Contributor
timestamp: July 28, 2012, 03:43:28 am
content: Hello DaveQuote from: EEVblog on July 18, 2012, 12:58:44 amPerhaps re-branded? Like the following ones:(Sorry, not really useful for you...)In Europe are available fromwww.tme.eu:Version 30V/5A non programmable, branded as "AXIOMET AX-3005D-1" for 94,64 € (111,63 AU$)http://www.tme.eu/html/EN/single-output-laboratory-power-supply-with-lcd/ramka_11397_EN_pelny.htmlVersion 60V/2A programmable, branded as "ACIOMET AX-6002P" for 106,51 € (125,64 AU$)http://www.tme.eu/html/EN/axiomet-programmable-power-supply-units/ramka_11398_EN_pelny.htmlTaxes are included, shipping + 4,95 € (5,83 AU$). If you get more then one, then a unit would be 10 Bucks cheaper...BTW: The Listing of selled PSU´s show no pictures of this devices. And says "in Stock = 0".(http://www.tme.eu/en/katalog/workshop-equipment_112607/?idp=1&search=axiomet&cleanParameters=1&id_category=112607#search=axiomet&s_field=accuracy&s_order=DESC&visible_params=2,1785,1314,622,541,2101,2023,1941,72,55,1747,1787,1813&used_params=622:14686;But, on request (on the product- sites) you will still see: They are in Stock.Reason? Your guess is sure as good as mine...To find the exact model you tested seems at this time impossible.Greetings from a "wacky German",HartmutP.S.: There is a Question, uprising from the darkest end of my mind...Come on, Dave. Say us the truth. Does the unit really fails? Or have you made some research for a hack?From 3005-P to 6005-P (or something like that)?

author: BrAtKo
author_rank: Newbie
timestamp: February 17, 2013, 07:44:23 pm
content: Hello Im going to buy this one from Axiomet AX-3005D maybe AX-3005DS (switching one) from tme.eu. Do you still not recommend this ? Another possible buy is from Matrix instead this. How can I determine the latest version please ? Id like to send question about the version to tme.eu before I buy one. ThanksHave a look for this Hantek for same price I think you get better quality. Would be nice to test ithttp://www.gotronik.pl/zasilacz-laboratoryjny-programowalny-pps2116a-produkcji-hantek-p-998.html

author: neslekkim
author_rank: Super Contributor
timestamp: May 20, 2014, 06:09:08 pm
content: Do anyone know how this psu remember the programmed settings?, mine (an tenma, looks same) forgets it's settings on one channel (I have an two channel version, looks like two 3005 that is just put next to each other in an chassi)

author: Pinkus
author_rank: Frequent Contributor
timestamp: May 27, 2014, 11:17:40 am
content: Quote from: neslekkim on May 20, 2014, 06:09:08 pmInteresting, I have the exact same problem with mine.It seems sometimes they either mix up the hardware (if they have two different modules) in the manufactory or the programming/setup after.I am too very interested in any help.