KORAD KA3005P - Page 1
Forum section: electronics / beginners

author: tony3d
author_rank: Frequent Contributor
timestamp: September 22, 2013, 02:29:18 pm
content: Hi All, just starting out in electronics, and I'm building up my bench equipment. I have been looking at two power supply's the KORAD KA3005P, and the BK Precision 1550. I'm leaning toward the KORAD KA3005P. I was going to order it from SRA solder, and was wondering if any of you have had experience ordering from them? I assume all the issues Dave found with the KORAD KA3005P supply have been resolved. Anyone have a vote for the BK?

author: Electro Fan
author_rank: Super Contributor
timestamp: September 22, 2013, 04:08:08 pm
content: I purchased a KA3005P from SRA Soldering. The Korad is a very good power supply (in it's price class). It's not perfect and I believe as with any model from any manufacturer a given unit can have problems but that takes us to SRA Soldering. On a scale of 1 (low) to 10 (high) they have been about a 12. They are off the charts (in an an excellent way). They are well managed, they are friendly and helpful, and they stand behind the products they sell. SRA Soldering really "gets" the notion of customer support and service. They care. I don't see how they could be better. (No I don't work there or have any relatives that do - I had never heard of them before purchasing the KA3005P.) Two big thumbs up for a KA3005P and SRA Soldering.PS, I have a BK Precision product (a function generator), and it is a very good product and BK Precision has also been a very good company from my perspective. I think the BK 1550 is a switching power supply. If that is what you want/need I'm betting it will be a decent product and it will be supported (at the manufacuturing level) by BK. The Korad KA3005P is a linear power supply and personally I had a preference for a linear supply. The BK is spec'd at 36V, 3A vs the Korad's 30V, 5A. I have a hunch the user interface (the rotary knob on the Korad and the memory and other buttons) might be more enjoyable to use than the BK UI but that's just a guess. Net, net: All 3 companies you mentioned have been good in my experience but I really, really liked SRA Soldering's approach to customer service and overall/so far I'm very happy with the KA3005P.

author: tony3d
author_rank: Frequent Contributor
timestamp: September 22, 2013, 05:20:27 pm
content: That's all good to hear. Thanks for the detailed response! So all these unit in stock now at SrA Solder, would all have the latest revision of the unit? I really like the memory buttons, a feature the BK does not have. Also, not thrilled the way the BK deals with setting the current limits. You have to short the terminals to set it. Looks like the Korda is just a button press correct? How long have you had it? Did you buy it directly from them or Amazon?

author: tony3d
author_rank: Frequent Contributor
timestamp: September 22, 2013, 06:53:37 pm
content: One more thing. Being a noob, I just want to make sure it's ok to plug one of these power supply's into a surge suppressed power strip? It's really all I can plug into. Also because I'm low on space my computer will be within a few inches of the power supply, can this pose any problems with the computers hard drive, and the rather large transformer in the power supply?

author: george graves
author_rank: Super Contributor
timestamp: September 22, 2013, 07:38:47 pm
content: +1 on SRA Soldering. Great customer support. Can't say enough good things about them.

author: Electro Fan
author_rank: Super Contributor
timestamp: September 22, 2013, 09:04:35 pm
content: Quote from: tony3d on September 22, 2013, 05:20:27 pmI think it's hard to say what units have what parts. I'm not sure that there is a widely understood rhyme or reason. My guess is that Korad ships what it ships and SRA sells what it gets. SRA has some ability to look inside products but I can't see how they could make a business out of taking the covers off every product they sell to see what's inside. Mostly what you get when you buy a Korad PS is a PS that survived a potentially serious reputation hit with the failed unit video and then it steadily got enough working unit user reports to recover. Beyond that you get SRA which I think will do the right thing to make a customer happy if a particular unit fails. (I had a couple administrative and technical/product problems along the way and SRA came through with flying colors.) As for Korad, I think they are a relativley small and young company that is learning as it goes but it's my sense they know how to make a good PS. I believe Korad is like other companies that are figuring out what combination of design and parts and QC is good enough to be competitve but not so good that they have to raise the price overly. At some point if they engineer in extra value and they keep the price down they are engineerng out value they could have kept as profit. It's a balancing act. Overall, for the price, I think the KA3005P is a good value and it is backed (to a very reasonable extent) by SRA.===> Just keep in mind, it's a Power Supply built in China and shipped about half way around the world that sells for about $120 - and it operates on about 110-120 volts of input - so use all prudent caution accordingly. Safety First.You set the output voltage and amperage with the buttons and the knob.I purchased the power supply several months ago through Amazon (which has been consistently good). I happen to have the PS plugged into a power strip that acts mostly as an extension cord.If you get a good unit I think you will like it. If you get a unit with a problem I think SRA will provide good customer support. YMMV

author: tony3d
author_rank: Frequent Contributor
timestamp: September 23, 2013, 12:32:45 am
content: Thanks. Not sure what you mean by all this though......" Just keep in mind, it's a Power Supply built in China and shipped about half way around the world that sells for about $120 - and it operates on about 110-120 volts of input - so use all prudent caution accordingly. Safety First."What precautions should I take? Things like don't leave it unattended at full output?

author: Paul Price
author_rank: Super Contributor
timestamp: September 23, 2013, 12:46:57 am
content: No, just don't use it while in the bath tub.

author: george graves
author_rank: Super Contributor
timestamp: September 23, 2013, 03:36:28 am
content: Quote from: Electro Fan on September 22, 2013, 09:04:35 pmI purchased two of them off of SRA solder - I asked before hand, and all the ones they sell have had the board replaced, or was new stock.Like I said, they have very good customer service.

author: tony3d
author_rank: Frequent Contributor
timestamp: September 23, 2013, 06:29:52 am
content: I'll give them a call tomorrow. For the money, I really don't think you can beat it.

author: uoficowboy
author_rank: Regular Contributor
timestamp: September 23, 2013, 04:46:56 pm
content: Quote from: tony3d on September 22, 2013, 02:29:18 pmI'm a big fan of old school electronics. With that said, this device is *pretty good*. Not amazing. But solid. There is a thread here about it and I posted in there my thoughts on the unit - mostly that it is solid, but the downsides:-it cannot be calibrated (and the current reading in mine has an offset to it - not awful but annoying all the same)-my power switch arrived broken-there is a software glitch (at least in mine) where it sometimes displays the set voltage rather than the output voltage while in current limiting mode. That glitch is why I don't use it terribly frequently. I lost all trust in that device when I caught that.It's still pretty good and is obviously super compact. But be aware that it has some limitations.

author: Bored@Work
author_rank: Super Contributor
timestamp: September 23, 2013, 04:53:42 pm
content: It always amazes me how many words people find to justify crapQuote from: uoficowboy on September 23, 2013, 04:46:56 pm

author: DavidDLC
author_rank: Frequent Contributor
timestamp: September 23, 2013, 04:55:08 pm
content: Quote from: george graves on September 22, 2013, 07:38:47 pmI also had a very good experience with SRA Soldering.

author: Unknown
author_rank: Unknown
timestamp: September 23, 2013, 05:41:18 pm
content: Quote from: Bored@Work on September 23, 2013, 04:53:42 pmMy fave on that -"I have never had a problem with it in the X Years I have used it""What about X, Y & Z problems""Yes it has all of those"If it has many problems then it isn't problem free.

author: tony3d
author_rank: Frequent Contributor
timestamp: September 23, 2013, 08:33:03 pm
content: Well, I went ahead, and ordered it from SRA Solder. They do seem very nice. I talked with Doug, and he personally checked one out for me. He said everything worked fine, and shipped it today. He told me all his stock is now new, so I can only hope I get a solid one. I really don't understand the switch failures, I mean it is mechanical, and it seems the failure rate was pretty high. Hope that has been resolved. I'll let everyone know how it goes. Has anyone been using one for more than a year with no failure of any kind? I just didn't have a lot of money to spend on this, so I can only hope it's ok. I did not by the programable as I'm on a Mac, and doubt there was software for it.

author: Electro Fan
author_rank: Super Contributor
timestamp: September 23, 2013, 10:17:50 pm
content: The Korad KA3005P can be user calibrated (relative to a DMM or some other reference device). I would think the KA3005D could use the same calibration process.

author: uoficowboy
author_rank: Regular Contributor
timestamp: September 24, 2013, 04:26:52 pm
content: Quote from: Electro Fan on September 23, 2013, 10:17:50 pmHow? The manual that came with the one I got doesn't say anything about that. Inside I don't remember seeing any pots for calibration, either.

author: uoficowboy
author_rank: Regular Contributor
timestamp: September 24, 2013, 04:28:39 pm
content: Quote from: Bored@Work on September 23, 2013, 04:53:42 pmNot trying to justify anything. It is an OK tool with a very low price tag. Delivers more bang for the buck than any other Chinese power supplies I've worked with.I still prefer my 30+ year old HP and PD gear, however.

author: Electro Fan
author_rank: Super Contributor
timestamp: September 24, 2013, 04:40:43 pm
content: Quote from: uoficowboy on September 24, 2013, 04:26:52 pmThe manual doesn't give the calibration process. If you contact Korad or SRA they should be able to email you a copy. It's mostly a sequence of front panel button pushes and dial turning. No need to take the cover off.

author: tony3d
author_rank: Frequent Contributor
timestamp: September 24, 2013, 05:46:10 pm
content: I should get mine Thursday from SRA Solder. I was just looking briefly at the online manual, and it doesn't actually tell you how to set the OVP, and OCP. Can someone explain how they are set? Thanks.

author: DavidDLC
author_rank: Frequent Contributor
timestamp: September 24, 2013, 07:24:40 pm
content: Quote from: uoficowboy on September 24, 2013, 04:26:52 pmCalibration procedure.I have not tried it yet, don't know if it works.I got this document from Korad Technologies.David.

author: uoficowboy
author_rank: Regular Contributor
timestamp: September 25, 2013, 12:12:05 am
content: Quote from: DavidDLC on September 24, 2013, 07:24:40 pmWow - the Engrish is strong with that document.I tried my best to follow it and I think it worked. I didn't check the cal immediately beforehand (I had noticed 6 months ago it being significantly off on the current measurement), but after my attempt at following their procedure the current measurement was accurate within 1ma or so. Cool!

author: robrenz
author_rank: Super Contributor
timestamp: September 25, 2013, 12:29:26 am
content: Quote from: uoficowboy on September 24, 2013, 04:28:39 pm

author: Electro Fan
author_rank: Super Contributor
timestamp: September 25, 2013, 01:06:51 am
content: Quote from: uoficowboy on September 25, 2013, 12:12:05 amYes, the writing could be improved but when that calibration process works it's pretty fulfilling. I think it will take time for Korad to prove it can consistently turn out products that have long term reliabilty but when their design is working it is pretty nice. I have done my best to calibrate the Korad and a couple DMMs using a 3rd Fluke DMM and 3 products from Voltage Standard and I think it's possible to get all this stuff within a very few (maybe 1-2?) milliamps and millivolts. I see things change slightly with temperature and I understand that burden voltage is a real thing, but it's pretty gratifying when you can get your power supply, DMMs, scope, and reference devices to align. Based on what I've seen with the Korad and it's calibration process I think the Korad can hold it's own with other entry and maybe even some mid level equipment. What we don't know besides the long term reliability is if the Korad has the "turn on farts" (I'm licensing that term from another EEVblogger who used it earlier today I think). If it the Korad is solid at AC turn on (and turn off), which I think it is (knock on wood), then it's really a very nice piece of equipment.I know that some folks here get a little testy about word waffling but the fact is that some of us don't have all that much hands-on EE design and testing knowledge and experience much less a long history of experience with the equipment we own so in my case I'd prefer to be candid and say "this is what I know, this is what I think so far, this is what I'm not sure about or just plain don't know, and by the way be aware that I'm very sure I don't know what I don't know".Having said all that, the Korad is cool when it's working and the calibration process (with just the front panel controls and no inside twiddling) is a very nice entry level power supply.EF

author: phaseshift
author_rank: Newbie
timestamp: September 25, 2013, 02:47:58 am
content: Tony3D,I bought the KORAD KA3005D-3S which is the 5 amp triple output supply. I bought it from SRA Solder 2 weeks ago and it has a fault. I'm going to post a separate thread tomorrow with pictures but I saw this thread and wanted to post in case anyone else is considering this item.I was all set to give the unit a glowing review until I got around to testing channel 3 which is spec'd at 5VDC ±50mV but was outputting better than 15.5 VDC. I brought this to the attention of SRA Solder and they shipped out a replacement regulator board for channel 3. I received this and did the replacement which is just removing the 10 cover screws, removing the cover and unscrewing the 4 board screws, disconnecting the 4 wire harnesses, swapping out the board, reconnecting the wire harnesses and putting back the screws.The new board had higher rated and better components (assuming they are not fakes) but still did not work. There is a pass transistor off board that is heat-sinked, chassis mounted and connected to the channel 3 regulator board via a wiring harness. There are also connectors for the input from the transformer, the channel output and sense harness. All connectors were solid, wiring looked correct, inputs voltage was proper but regulation was non existent, the AC from the transformer was just being rectified, filtered and fed to the channel output. I suspect a bad pass transistor but did not have the time to test. I informed SRA Solder and they did not have another new unit in stock to ship so they are letting me keep this unit until they get a fresh shipment. They did not have an ETA on when the new shipment would come in.Overall, SRA Solder has been a pleasure to deal with so far and the unit performs beautifully outside of the issue with channel 3. I really want this issue to be resolved because anything else in this price range ($169 USD) has less features for the money e.g. no load switches, no programmable settings, fine/course adjustment instead of 1 rotary encoder/channel.Again, I'll post pictures tomorrow but the unit looks decent for the price. If they get this issue fixed and the unit lasts then I think it's worth serious consideration. The product has real potential, they just need to button some of these issues up. Happy to answer any questions you might have in the interim.

author: tony3d
author_rank: Frequent Contributor
timestamp: September 25, 2013, 08:19:47 am
content: Ouch! I'm wondering if anybody actually gets one that is 100%. How is it cosmetically? Have you had any issues with the power switch? Was reading that many people had those fail. Does everything else on the other two channels operate correctly? All these failure certainly don't instill a lot of faith, but as you say the unit has so much potential. Looking forward to seeing the pictures tomorrow. Even if everything is ok, I wonder how these things will last? What scares me is they have had quite a long time to fix all these issues, and yet they persist. Something just seems wrong with that. Although being an audiophile, I remember buying a new Crown IC150 preamp which was completely dead right out of the box in the mid 70's, and they were consider the best in there day. Go figure. I'm almost at the point of being afraid to turn the thing on at all for fear it may blow up! I'm a noob to this hobby, and just in the early stages of learning, so I was wondering what procedures you recommend I use to test my unit for proper operation?

author: tony3d
author_rank: Frequent Contributor
timestamp: September 26, 2013, 12:38:47 pm
content: Do you think I would be wise to remove the cover, and check out the innards before firing it up? I don't want to void the SRA Solder warranty. It's out for delivery now.

author: george graves
author_rank: Super Contributor
timestamp: September 26, 2013, 10:14:09 pm
content: It's be fine. Not sure why you're so worked up about for a $100 power supply.