Korad KA3005P power supply: UI changes - Page 1
Forum section: electronics / testgear

author: ebastler
author_rank: Super Contributor
timestamp: April 12, 2021, 09:27:06 am
content: Just a quick update on this popular low-cost power supply: I just received one of these, ordered via Welectron in Germany, after a long wait for a new shipment to arrive from China. Compared to what I have seen in videos and written reviews, Korad have made some improvements to the user interface:The M5 LED (5th memory, which did not have its own key anyway) has been replaced by a LOCK LED. I believe this was in the original version too, and at some point got replaced by the M5 LED.Significant improvement: A short press of the "Lock" button enters a mode where you can adjust voltage or current via the encoder and arrow buttons without any timeout. There were many complaints about the short timeout in earlier versions. To lock and unlock the keypad, a long press on Lock is needed.Unchanged: The behavior of the "memory" buttons. Any change to the current or voltage setting will immediately change that memory preset.Changed? It is easy to accidentally tap one of the M1..M4 buttons and set the Korad to a different output voltage. But it automatically switches its output OFF whenever you switch to a differen memory preset, so you don't fry your load. Not sure whether this behavior is new? I don't recall seeing it mentioned, but have not watched out for it in the reviews.Cosmetics: The sheet metal enclosure is now charcoal-colored. The 7-segment display for voltage is green, current display is red. The status LEDs for "ON" and "constant voltage" are green, the others remain red.My KA3005P still came with binding posts (with standard pitch), not the stupid safety jacks shown in some photos. Nice!Overall, I am happy to see that Korad continues to make incremental improvements to this product. I have not looked inside and have not measured any output behavior yet. Let's hope that they did not change anything for the worse!

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 12, 2021, 11:43:58 am
content: Is there any way to tell which version a vendor is selling? Or is it a crap shoot (except for physical changes to the exterior)?

author: hexreader
author_rank: Frequent Contributor
timestamp: April 12, 2021, 11:51:05 am
content: You forgot to mention the feature that this PSU is (in)famous for.Is the fan any quieter?I live near an airport and I would like to be able to hear the military jets taking off with full after-burners - without the Korad fan noise drowning them out

author: MikeK
author_rank: Super Contributor
timestamp: April 12, 2021, 12:25:11 pm
content: Quote from: ebastler on April 12, 2021, 09:27:06 amThis one is very annoying. And at odds with common sense and proper behavior. Essentially, you have to give up one of the presets so that it can become the "current setting". "Current" meaning time, not electricity.If I manually tune the radio in my car it doesn't change the presets. Nor should it! Changing the power supply preset should be just like the car radio...long press to save.

author: ebastler
author_rank: Super Contributor
timestamp: April 12, 2021, 01:43:24 pm
content: Quote from: YurkshireLad on April 12, 2021, 11:43:58 amThe model number is unchanged, KA3005P, and I would not trust the vendors to update the pictures on their websites. So I would specifically ask the vendor about the changes which are visible externally -- the "LOCK" instead of "M5" label on the LED is visible with the unit turned off, and the green digits for the voltage are obvious when it is turned on.Quote from: hexreader on April 12, 2021, 11:51:05 amUnder light load the fan is very quiet -- much less audible than my Siglent SDG2042X, which in turn is much quieter than the Rigol DS1000Z scope. When I short the outputs in the 30V/5A setting, the fan gets cranked up gradually and does become louder than the Rigol -- but I can still tell whether the Rigol fan is on or off, it does not get drowned out.The noise one hears under load is from the airflow, not from the fan bearing, and is not unpleasant in pitch to my ears. The fan speed control is temperature-dependent, not simply derived from the voltage/current draw. It is not "nervous" but ramps up and down gradually. Hence I would say Korad did a decent job within the constraints of the fan size.Quote from: MikeK on April 12, 2021, 12:25:11 pmYes, that one is a disappointment. Seems that it would have been very easy to improve via a software change -- e.g. by requiring a long press of a memory button to save the current setting to it. Maybe next year... ;-)

author: ebastler
author_rank: Super Contributor
timestamp: April 13, 2021, 10:24:32 am
content: Turns out that even Korad has not gotten around to changing the product description on their website,http://www.koradtechnology.com/product/14.html. For reference, the attached photo shows what my new unit looks like -- note the green LEDs, LOCK LED and the dark case.I assume the LOCK LED was brought back to better support the extended behavior of the LOCK button: long press to lock the keypad, short press to get to "continuous adjustment" mode. I like the changes they made and the (unchanged) compact package. Got a second unit on order!

author: masterx81
author_rank: Frequent Contributor
timestamp: April 13, 2021, 12:24:10 pm
content: On my 3305 the most annoying thing is the really small timeout of the adjustments, nice that they are starting to fix it on the single units.

author: MikeK
author_rank: Super Contributor
timestamp: April 13, 2021, 05:36:12 pm
content: Even nicer would be the source code so that people who actually use it can develop the proper firmware.

author: ebastler
author_rank: Super Contributor
timestamp: April 13, 2021, 05:43:28 pm
content: Quote from: MikeK on April 13, 2021, 05:36:12 pmI assume they intentionally keep the lid on the software to discourage even-lower-cost competitors from copying it. More likely than not even the binary is read-protected inside its microcontroller?But the software as it stands is quite usable in my view. My only remaining wish would be a different behavior of the memory buttons -- short press to recall, long press to store a setting or something along those lines.

author: MikeK
author_rank: Super Contributor
timestamp: April 13, 2021, 05:53:44 pm
content: Quote from: ebastler on April 13, 2021, 10:24:32 amI think yours is a revision newer than mine, which was purchased from Amazon in October 2020. All of my LEDs are red. They may have taken a cue from a YouTube mod to change the output LED...a change I plan to make eventually. I would like to see OVP/OVC as one color, CC/CV another, and OUT a third color. At the very least I want OUT to be different than all other colors. Have you imaged the inside?

author: ebastler
author_rank: Super Contributor
timestamp: April 13, 2021, 06:05:26 pm
content: Quote from: MikeK on April 13, 2021, 05:53:44 pmI have briefly looked inside to check for proper grounding, but have not taken any pictures, sorry. I'll open it again and add some photos here over the next couple of days. All nice and tidy on the inside; in addition to the cable ties and tidy routing I knew from photos, I noticed that they have secured all plugs with some white glue (presumably removable...).The only thing that struck me as strange was that the power PCB attached to the heatsink is actually comprised of two PCBs sitting next to each other. Each pretty exactly half the size of the heatsink, mounted by two shared screws in the middle plus separate screws near the outer edges. The leads from the transistors (?) on one PCB were soldered to both PCBs to contact them, if I saw that correctly. Not sure what cost-savings or reliabilty improvement that is meant to bring?? I will look more closely and try to get photos of this part too.

author: MikeK
author_rank: Super Contributor
timestamp: April 13, 2021, 06:19:19 pm
content: Quote from: ebastler on April 13, 2021, 06:05:26 pmYep, mine's the same:

author: ebastler
author_rank: Super Contributor
timestamp: April 13, 2021, 06:33:04 pm
content: Quote from: MikeK on April 13, 2021, 06:19:19 pmMany thanks for the pictures! Yes, exactly the same in mine, including the elegant two-tone look of the PCB in black and green.Same glue on the plugs as well. So it seems that they only changed the LED colors and the firmware in the most recent revision.

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 13, 2021, 06:56:08 pm
content: It just occurred to me that this KA3005D has the LOCK LED. Does that make this one an original version or an updated version? Or did the KA3005D always have it? Confusing.https://www.amazon.ca/dp/B0084JFWNY/

author: ebastler
author_rank: Super Contributor
timestamp: April 13, 2021, 07:41:56 pm
content: Quote from: YurkshireLad on April 13, 2021, 06:56:08 pmAs mentioned in the original post above, I believe the KA3000 series originally started out with the LOCK LED. Then at some point Korad thought it would be a good idea to offer the 5th memory -- without adding a 5th button for it, hence the awkward way of addressing it indirectly via the encoder. Most recently, with the introduction of the overloaded LOCK button (short and long press), having a clear indication for the LOCKed status became more important again; so they dropped the 5th memory and went back to a LOCK LED.I guess the picture in that Amazon offer shows a very early version of the power supply, since it does not have the green display. I have seen these pictures occasionally, also in some of the old instruction PDFs that float around on the 'net. It's probably not the exact version they ship; unless they have very recently received new stock you would likely still get a unit with the "M5" LED.But hey, it's "Certified frustration-free" according to the seller, so what could possibly go wrong?

author: ebastler
author_rank: Super Contributor
timestamp: April 21, 2021, 03:15:07 pm
content: One more update: I just received the second unit I had ordered after being pleasantly surprised by the first one. Number two has a slightly less pleasant fan; I can hear what seems to be a little bearing noise. Nothing terrible, no rattling or such, it sound like just a bit of extra friction. So far my "solution" is simply to place the two units next to each other on the shelf such that the quieter one is closer to me...Controls and LEDs are exactly the same on both units, as one would expect.

author: NeonTron
author_rank: Newbie
timestamp: September 02, 2021, 03:59:30 am
content: Can you please post a picture of the back of the unit? I'm wondering if the black case model from Welectron can handle 110V input. The version on Amazon seems capable of being switched between 110V and 220V (see attached picture).

author: ebastler
author_rank: Super Contributor
timestamp: September 02, 2021, 05:52:33 am
content: The updated Korad version I received from Welectron is labelled for 230V, and does not have a selection switch for the mains voltage -- just like the earlier version.Unfortunately there is no easy way to re-wire the transformer primary windings inside the unit either: Only two wires are brought out from the transformer,nottwo separate primary windings which one could wire either in series or parallel. (See the attached photo -- mains jack on the left, power switch on the right.) It seems that Korad actually installs different transformers in the 230V vs. 110V versions.

author: eevblogger88
author_rank: Contributor
timestamp: April 16, 2022, 05:17:37 pm
content: Quote from: ebastler on April 21, 2021, 03:15:07 pmWhat's the most quiet fan that you can recommend to change the stock one in the Konrad?

author: ebastler
author_rank: Super Contributor
timestamp: April 16, 2022, 08:51:51 pm
content: Quote from: eevblogger88 on April 16, 2022, 05:17:37 pmI don't have personal experience replacing the fan; I am still running the stock fans on both my units. Any 80 mm * 25 mm fan rated at 12V should work in principle.If you Google "korad ka3005p fan replacement" you will find various Youtube videos showing fan replacements. Artic Cooling F8, Noctua NF R8, and some Panaflo brushless fan are mentioned as replacements there. I think all of them come with a different plug than the one used in the Korad supply, so you will have to swap out the plug or get an adapter.Having said that -- are you already using a KA3005P, and have confirmed that the fan noise is an issue for you? I would definitely test-drive it for a while; as mentioned, I found that I don't mind the fan.Edit: Fixed typo in the model number; the KA3005P(with USB/serial interface) is the most popular model, and the one discussed here.

author: MikeK
author_rank: Super Contributor
timestamp: April 16, 2022, 09:07:41 pm
content: Quote from: ebastler on April 16, 2022, 08:51:51 pmI agree with ebastler. The fan in my Korad is not noisy at all. If you do need to replace it, I put a Noctua NF-A6x25 FLX in my [formerly noisy] Rigol DS1052E oscilloscope and it is pleasantly quiet. I'm not saying it fits the Korad PS (I don't know), but I'm at least recommending the brand.

author: ebastler
author_rank: Super Contributor
timestamp: April 17, 2022, 07:13:38 am
content: @eevblogger88, one more comment. I just saw from your other posts that you are in the process of setting up an electronics bench from scratch, intending to do repair work on phones and computers.Do you plan to do that for money, by repairing for others and/or making Youtube videos? If so, have you been able to gain some practical experience yet? Watching Youtube videos by Rossman and Northridgefix and buying a bunch of equipment is not the best approach to become productive, I think.E.g. it would be so much better to try working with a binocular microscope vs. a video microscope yourself, rather than listening to what the guy at Northridgefix prefers. (I don't doubt he knows what he is doing, but what works for you will strongly depend on personal preference and experience!)If you have not done so yet, and have any opportunity to make it happen, I would recommend that you look for an internship in a repair shop.

author: tooki
author_rank: Super Contributor
timestamp: April 18, 2022, 07:44:25 pm
content: Quote from: MikeK on April 16, 2022, 09:07:41 pmEarly KA3005P units like mine at home have a very different heatsink from later units, one that causes far more turbulent airflow. Replacing the fan in those (which I did in mine) does improve noise, but not by very much. It’s my understanding that the new heatsink design is much quieter.I have a recent KA3005D at work and it’s noticeably quieter.

author: MikeK
author_rank: Super Contributor
timestamp: April 18, 2022, 08:32:35 pm
content: Since this thread is about UI changes, I want the memory buttons and the indicators (LEDs) in the same bloody place. Either put the LED right next to the button, or inside the button.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: April 21, 2022, 07:41:09 am
content: Have 2 re-badged versions of these. One is very finicky in flicking voltage values up down when using the wheel to adjust voltage (adjst voltage of current). It can flick up/down wildly with minor encoder wheel movement. Its is extremely annoying. Mainly noted when adjusting points of a volt/current.I have 2 of them...the other is ok but a little twitchy like the first.Its as if its not counting the encoder correctly or makes multiple jumps on one encoder click. Going to have to try fix this....real PITA.

author: bateau020
author_rank: Frequent Contributor
timestamp: April 21, 2022, 08:31:23 pm
content: Quote from: tooki on April 18, 2022, 07:44:25 pmNot only that. Mine (and probably also yours, many versions exist though) uses a fairly low frequency PWM to drive the fan, making it jitter. Hence the noise.Adding a cap in // to the fan lowers the noise a lot, and is easy to do.I however just installed an independent temperature driven fan driver circuit and replaced the fans with quieter 4 pin PWM fans. Completely silent now, unless I drive the PSU hard. And even then, it is still a lot better than before.

author: MikeK
author_rank: Super Contributor
timestamp: April 22, 2022, 01:51:02 pm
content: Quote from: bateau020 on April 21, 2022, 08:31:23 pmAre you using an NTC thermistor and an 8-pin uC?

author: bateau020
author_rank: Frequent Contributor
timestamp: April 22, 2022, 02:48:43 pm
content: Even cheaper: one of the many temp controlled fan controller boards from aliexpress. I used a dual controller, since I have the 2 channel version of the PSU. But many single channel versions also exist. Took the power from one of the cables going to the front panel (18V AC? if I remember right), created the controller board power via a buck converter (you guess where I got the latter) and mounted it all on a bracket. For some things buying is cheaper than building.

author: MikeK
author_rank: Super Contributor
timestamp: April 22, 2022, 03:12:04 pm
content: Is the fan controller board using a uC? I may make this mod to my PS, but I'd rather not have a uC that could fail and cause overheating. (We all make coding mistakes.) I'm thinking an NTC and comparator.

author: bateau020
author_rank: Frequent Contributor
timestamp: April 22, 2022, 03:19:36 pm
content: There are specialised chips for fan controlling, but an attiny214 for example could also do it. Github has some fan controller projects. Just use the watchdog or do repeated resets. If you want more security, you could add a comparator and a buzzer or relay for example.edit: or you could use a standard thermal fuse that you place in the mains line.

author: Geoff-AU
author_rank: Frequent Contributor
timestamp: May 24, 2022, 12:28:01 am
content: Quote from: wasyoungonce on April 21, 2022, 07:41:09 amReplace the rotary encoder. It's a bit of digging to access it but highly worthwhile. The original encoder contacts go intermittent and that can cause all sorts of fun things, like trying to reduce the voltage and having it shoot up by 6 or 7 volts. Certainly enough to fry a board if you are doing it "live". I have the dual supply and replaced rotary on both sides, working perfectly again now.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: May 25, 2022, 04:52:21 am
content: Interesting, is it possible to extract firmware from the new version and flash it into old version?By the way, I also have this PSU and did a "triple" mod, to make it far less noisy.1. Fan is replaced with a far more silent version. Made by Nidec.2. Fan is mounted onto silicone rubber padding, to reduce vibration noise3. heatsink is not mounted on fan any more, so it can't transfer fan noise onto main body.If anyone wants to skip all this and just have "Korad" grade PSU, but without noise, without short timeout and other issues, I suggest you to buy eTOMMENS eTM-305DP. It is basically same as this Korad, but has different fan management system (fan is off in most cases), fan is less noisy, and issue with knob timeout is solved too. Also, there's a service menu, which can be accessed by holding output enable button, while powering unit on. You can adjust beep on/off, calibrate meters and many other things from that menu.

author: Pfriemler
author_rank: Regular Contributor
timestamp: January 11, 2023, 09:54:54 pm
content: Sorry for rehashing the thread....Just got my KA3005+ from Welectron (the screw terminals are sold out by the way). These are my results from a first test:the Korad always starts with the settings in M1 (don't know if this is new or not).whenever you change a value after calling a setting from M1..M4, the corresponding M1..M4 LED stops lighting.The memory setting is not updated until I long press the Mx buttonA short press on  still provides an easy way to change the voltage OR the current (whichever was set last), selecting the digit to be changed with <- or -> as usual.The digit remains blinking, as long as the output is off.If output is on, the blinking stops after a few seconds.the digit to be set changes to 1/10V and 10mAif it was set to 1V/0.1A or 10V/1A.If the "cursor" was on 10mV/1mA, it remains there. This could be useful to avoid big changes by accident, but keeps possible small adjustment as long as this mode is active.The dot in the most right digit blinks as long as this mode ist active.Do I have a newer version? "*IDN?" answer is "KORAD KA3005P V5.8 SN:03203xxx" (dunno if the serial is secret)edit: corrections of list, version informationedit2: correction of behaviour

author: ebastler
author_rank: Super Contributor
timestamp: January 12, 2023, 06:21:55 am
content: Yes, that must definitely be a new version! The memory behavior you describe in your second bullet (long press required to store changes) implements a long-requested change. As stated in my original post in this thread, the version I received in April 2021 still changed the memory values as soon as you changed a setting.I must say I'm impressed that Korad continues to listen to user feedback and make improvements to this older, low-cost product. (Although they are taking their time...)The "always starts at M1 on power-up" behavior is unchanged from prior versions. The automatic jump to 1/10V or 1/100 A in "permanent adjustment" mode is new, I believe -- and I am not sure whether that one is an improvement?

author: Pfriemler
author_rank: Regular Contributor
timestamp: January 12, 2023, 04:55:48 pm
content: eBastler* what's your FW version?Yes, I was surprised by these news in behavior - it is as you will expect it, regarding the memories. And to store safe values to M1 is easy. I like it much more than returning to the last settings after power off. My Matrix MPS3206 is very special in this...I think, the 1/10V as default is rather not that what most users will like.

author: ebastler
author_rank: Super Contributor
timestamp: January 12, 2023, 06:23:01 pm
content: My two KA3005P's are on firmware version 5.5, they say.I double-checked the behavior of the permanent adjustment mode while I was at it. After a short press on LOCK, I can select current or voltage and select a digit, and then the adjustment mode will happily stay on that digit forever. (Unless I change it again via the <> buttons, of course.) The adjustable digit also keeps flashing at 1 Hz, which is a bit obtrusive but provides a clear visual reminder that the adjustment knob is active and will affect this digit.Time for version 5.9, which combines the new memory behavior and the old permanent adjustment mode.Ah well, we will most likely never get firmware upgrades for the existing units. Nevertheless, kudos to Korad for continuing to make improvements!

author: Pfriemler
author_rank: Regular Contributor
timestamp: January 18, 2023, 03:57:26 pm
content: Quote from: ebastler on January 12, 2023, 06:23:01 pmI just took a deeper look at mine @ FW5.8: The digit remains blinking as long as the output is off. But the "instant change mode" isn't active yet (if output is off), but the dot is on, if you press .If output is on, the blinking stops after a few seconds.And now:The (now invisible) cursorremains at 100mV/10mA and 10mV/1mA. Small adjustments are still possible!Only if the cursor was on 1V/100mA or 10V/1A, it jumps back to 100mV/10mA.The just changed digit blinks as usual and stops blinking after a few seconds.As long as (esp. in current changing mode) a digit blinks, the display shows the "set" value, if nothing blinks, the measured value.My post above is corrected.With this, I am very happy. The activated "permanent adjustment mode" is more safe, the risk of (too) big steps is reduced, small adjustments are not affected.

author: smallfreak
author_rank: Contributor
timestamp: April 25, 2023, 09:15:46 pm
content: I'm curious. Are there still two different models of this PSU available or are meanwhile all of them the "plus" version with the green voltage display and a "lock" indicator instead of an M5?Welectron lists them as separate but also lists all of them as "not available" so this does not necessarily mean that the "non plus" versions will ever become available again. Everyone else still shows the "all red/M5 LED" images but I doubt that Korad would keep two nearly identical models in production.

author: IvanBayan
author_rank: Newbie
timestamp: May 31, 2023, 12:16:19 am
content: It's turned out that one more revision or similar version exist, it's called KKG305P.The main announced differences: it has wattage display, solid state relays instead of regular (at least I can't hear clicking), external sense input, external trigger/switch input and RS487+Modbus.I've managed to bought one. The most interesting thing that you can't find it on official Korad's web page.I asked them via email about differences with KA300P and got the next answer "KKG305P is our KORAD product. We will put it on the website later. And KKG305P has more functions, higher performance and better quality than KA3005P."

author: ebastler
author_rank: Super Contributor
timestamp: May 31, 2023, 05:37:20 am
content: Hey, and there is a "Set" button! Which hopefully means that the M1..M5 presets will only be changed (and stored) if one explicitly requests that by pressing "Set"?

author: Pfriemler
author_rank: Regular Contributor
timestamp: May 31, 2023, 03:48:56 pm
content: Quote from: IvanBayan on May 31, 2023, 12:16:19 amPlease remember the thread title: UI changes in KA3005P.The KKG305P is a complete new and different device (even a KD3005 is not comparable to the KA3005) and it's definitely worth a new thread here.Quote from: ebastler on May 31, 2023, 05:37:20 amWith my (new) KA3005P, M1..M4 (no M5, LED shows the LOCK button status), no settings are changed by accident, only by a long button pressure. M1 is recalled during power up and should be programmed with safe values. I love this behavior.

author: ddrl46
author_rank: Regular Contributor
timestamp: May 31, 2023, 08:06:27 pm
content: It appears that another variant has shown up, the KA3005PS / KA3005PEA.

author: Pfriemler
author_rank: Regular Contributor
timestamp: May 31, 2023, 08:57:23 pm
content: Both are listet @ Eleshop.eu. Low noise fan, better amps resolution, PEA with external on/off and sense.Main specs same as KA3005P. Maybe I am wrong and these devices are ideed new housings with basically the same power circuits.But SSR replacing the relays ... is this a good idea at all?

author: ebastler
author_rank: Super Contributor
timestamp: May 31, 2023, 09:17:44 pm
content: From a UI perspective, I am disappointed that Korad did not switch to translucent rubber buttons with the indicator LEDs back-illuminating each button. That can't be significantly more expensive than the current setup, and would make it so much more obvious which indicator maps to which function button.

author: 5U4GB
author_rank: Super Contributor
timestamp: February 03, 2024, 09:47:07 am
content: Quote from: ebastler on April 12, 2021, 01:43:24 pmJust got a 3005D (not P) which is dated December 2022 and this also has the updates described here, but not the case colour change. I'll post a link to a teardown a bit later on, but one thing I noticed is that the fan only has two wires and no sense wire, so the reason why the ramp up is slow could be because the control software has no idea what speed the fan is running at and has to just gradually ramp it up and see what the HS temperature changes to.In general though the heatsink layout is pretty strange both for the original and updated heatsink, instead of the air flowing across the fins the HS is mostly blocking the air flow, which I would imagine leads to both poor performance and a lot of unnecessary noise because there's a solid block of metal a few cm from the blades. What were they thinking?

author: ebastler
author_rank: Super Contributor
timestamp: February 03, 2024, 09:58:06 am
content: Quote from: 5U4GB on February 03, 2024, 09:47:07 amThat less-than-ideal arrangement probably dates back to the first generation of KA3005s. Those did not have a proper heatsink with fins at all, but essentially a flat aluminium plate with some token "fingers" along the edges, made by cutting and bending the plate. Blast some air straight onto the plate, done.Can be seen in Dave's original teardown video from 2013:https://youtu.be/g94mpom2Ahs

author: 5U4GB
author_rank: Super Contributor
timestamp: February 03, 2024, 10:13:24 am
content: Yeah, and you can't easily change it because they're replaced the fake Rubycons with a single giant cap that would get in the way of the transformer if you rotated it 90 degrees to allow flow down the vanes:You'd also, because of the metal plate to force airflow across the transformer, get very poor airflow across the heatsink.

author: 5U4GB
author_rank: Super Contributor
timestamp: February 03, 2024, 11:44:23 am
content: Just posted abunch of photos and commentsof whatever version it is they're shipping now.

author: Pfriemler
author_rank: Regular Contributor
timestamp: February 03, 2024, 02:45:57 pm
content: Well, as far as I remember there was a single main cap all the time, even in the first version Dave teared down.I do think different to the fan behaviour: Unlike any PC stuff with monitoring hardware, a tacho signal from the fan is rather seldom in such hardware and even a PWM controlled (4 wire) fan is a kind of overkill to such a device. The Korad does not have to know about the speed of the fan, as long as there's a sufficent correlation between rotation speed and the supplied voltage - which is the case, normally.And for the air flow design: If you place a fan this way directly above the heat sink, you have a powerful airflow through the cooler even in the direction of suction, as here. The cooling would be better if you change the air direction as suggested by some users, but I would never heat the components inside this unnecessary way.Ramping speed may come from the fan regulation. Unlike the first versions with a load regulated fan speed the cooler follows the load with a load dependent delay, very normal. I remember my Voltcraft DPS2010, famous for a stupid fan regulation: the fan starts at about 42 °C and reaches may speed @ 50 °C, regulation far too steep, which results in an oscillating speed of the fan with middle loads. And, full fan speed with any current >40% of maximum. That's annoying!As mentioned above, I have a new Welectron design model and got me another second hand, RND 320 KA3005P, answering "V5.5" on *IDN?. I have no idea how long this version is on market (and how old it is). Now I can compare both versions in behaviour and performance and do like the improvements a bit more. At a first glance, the fan speed at no load issignificantlylower with the new version.Next week I will make a "light teardown" of both to examine differences, before I go and fix the non lit OVP and OCP LEDs and the (sometimes) snarring fan.

author: Pfriemler
author_rank: Regular Contributor
timestamp: February 05, 2024, 08:58:04 pm
content: Hard to believe: both OVP and OCP status LEDs were dead. Because I wanted to change C.V. and output LED, I got two spare LEDs and solder them to OCP and OVP. After that, the third LED was broken.Btw. the LEDs are of a dedicate low current type. They need not more than 3 mA for full brightness.The differences of both RND (Reichelt) KA3005P V5.5 and KORAD (Welectron) V5.8 are only a few:- there was no metal sheet inside above the transformer- the com board looks complete differentThe red/green led board and the housing color are obvious.To my very surprise, there's no difference in fan control. Both uses 120 Hz PWM, I got no differences with the scope. But the fan seems to be different in sound as well as in air flow. I even put both devices side by side and let them power the opposite's fan - the Welectron's one stays more quiet.If I stress both versions with a 5 amps full short circuit, the semiconductors on power board heat up to ~110°C, sometimes with a 2-3 degrees difference, so there's no lack n cooling under load.Also the sound measurements show a rather light difference under full load (49 vs 51 dBC) and idle (34 vs 38 dBC, ~1m distance, back side, yet no housings)

author: 5U4GB
author_rank: Super Contributor
timestamp: February 11, 2024, 09:09:59 am
content: Quote from: Pfriemler on May 31, 2023, 03:48:56 pmIt also seems to be practically nonexistent, Botland.de has it and that's about it, and of their range the 305P model is marked as EOL. Also fromone of the very few discussions of itit essentially looks like a fixed KA/D3005 rather than a new product, e.g. the annoying adjustment-lock is removable as with newer-FW 3005s, the memory-overwrite is fixed as with newer-FW 3005s... it looks like the KKG305s are just 3005s with window dressing, so this is probably the best place to discuss them, because they seem to be just 3005s with UI fixes.

author: 5U4GB
author_rank: Super Contributor
timestamp: February 13, 2024, 09:46:47 am
content: Quote from: ebastler on April 12, 2021, 09:27:06 amJust found where I'd seen this earlier right at the start of the thread, this change doesn't seem to have made it into the currently-shipping KA3005D yet, it still has the annoying short timeout where you keep having to press the Volt/Amp button every single time you make a change Wanted to test the power consumption and light output of a 24V LED strip at lower voltages and every 1V step required re-enabling changes again, grrr.

author: Pfriemler
author_rank: Regular Contributor
timestamp: February 13, 2024, 10:03:08 pm
content: Quote from: 5U4GB on February 13, 2024, 09:46:47 amIt would not suprise me if there are still "old" versions in stock to sold as new after two years. On the other hand, we still have no other versions than the Welectron KA3005P+ series proved with the newer firmware. I couldn't believe that KORAD did some changes only for Welectron while still deliverung "old versions" to the rest of the world.

author: 5U4GB
author_rank: Super Contributor
timestamp: February 14, 2024, 09:58:34 am
content: Theone I gotwas dated December 2022, 1 1/2 years after the post describing the change, so it's probably not just a supply-chain issue.Does anyone who has a KKG-series one want to post photos of the insides? For that matter, does anyone actuallyhavea KKG? Fromthis Korad catalogueposted to the mikrocontroller.net forums they have a pretty confusing variety of models allegedly out there now.

author: littleboot
author_rank: Regular Contributor
timestamp: February 28, 2024, 12:54:50 pm
content: instead of a custom temperature fan controller, I bought a PWM fan controller on Aliexpress:Search for "12V PWM fan controller"https://vi.aliexpress.com/item/32973504131.htmlPrices fluctuate a lot, the one I ordered was €2.79 deliveredOperating instruction of this thing are very badly described, I found this video explaining how to change the temperate and fan settings:and a thin 80mm fan:https://vi.aliexpress.com/item/1005005952005094.htmlNO-8010-PWM-BLACK€4.75 deliveredThin was not required but I wanted a branded fan (assuminh it would be better, more silent).Everything works perfectly, the lab supply is silent now!I forgot to add A additional capacitor on the 12V fan supply but, I have not checked the ripple.... just thought of it while typing this post(maybe I open it up again but seems to work perfectly so I think I will leave it like this)- Put the thermristor of the PWM fan controller into the hole next to the NTC on the board.- Stored the original fan inside the supply, If I ever need it

author: 5U4GB
author_rank: Super Contributor
timestamp: February 29, 2024, 11:32:50 am
content: Quote from: littleboot on February 28, 2024, 12:54:50 pmHmm, for only a tiny bit more you can get something mainstream like the Arctic temperature-controlled fans, they use a FDB for quiet operation and come with a built-in temperature sensor on a short cable. For an 80mm fan you want theArctic F8 TC. I used to have one of those somewhere but ditched a whole bunch of fans ("the fan club") during a clearout a year or two back, sigh.

author: 5U4GB
author_rank: Super Contributor
timestamp: February 29, 2024, 11:48:31 am
content: Quote from: littleboot on February 28, 2024, 12:54:50 pmThat would be interesting to see and was actually my first thought, have you partially negated one of the main benefits of a linear supply by adding switching noise to parts of the circuit?

author: littleboot
author_rank: Regular Contributor
timestamp: February 29, 2024, 12:53:14 pm
content: Quote from: 5U4GB on February 29, 2024, 11:48:31 amThank you for your reply I decided to open up the lab supply again.I wish I knew about the Arctic F8 TC sooner I would have probably used it, however I'm quite happy with the AliExpress fan controller because I can configure it.I'm glad I opened up the supply again and did a measurement, the supply noise is horrendous (did not expect it to be this bad). When I'm finished with the measurements I will post measurement data before and after as well

author: littleboot
author_rank: Regular Contributor
timestamp: February 29, 2024, 09:49:53 pm
content: Finished the measurements, as mentioned before the supply voltage is horrible, not only that it is actually load dependent ~20Vrms (light load, new fan standby speed) not 12Vrms.I don't like the over voltage for the fan, but if it dies it dies, problem for future meThe fan controller AliExpress page is says it will operate from 8V to 18V. I looked up the LDO part number (78l05) on LCSC and it seems it can handle 35V max, assuming the 0603 capacitors 0.33uf and 0.1uF are 35V, 50V or higher I should be fine.I attached my full notes including measurement data as pdf.I measured the supply voltage with my scope in the following situations:- original fan;- original fan +200 uF (two SMD solidstate 25V 100uF capacitorshttps://www.lcsc.com/product-detail/Solid-Capacitors_AISHI-Aihua-Group-SVZ1EM101E06E00RAXXX_C320569.html)- fan controller without fan- fan controller without fan +200 uF- fan controller with fan (ID-COOLING NO-8010-PWM)- fan controller with fan (ID-COOLING NO-8010-PWM) + 200uFagain another quick project that took way longer then expected

author: jewelie
author_rank: Regular Contributor
timestamp: April 27, 2024, 10:33:51 pm
content: For reference the attached photos are of the Tenma 72-10480 I got from CPC Farnell late in 2022 (https://cpc.farnell.com/tenma/72-10480/power-supply-1ch-30v-3a-adjustable/dp/IN06822) which is clearly a rebadged KA3003.I had a noisy fan issue that went away with a 25V 220uF electrolytic (poked deep into the connector, which is a bit hacky but it fits nice and tightly.)It's clear the fan doesn't cope that well with PWM.Oddly, with the capacitor, the fan runs faster at "full" loaded speed, which seems odd, unless the output isn't actually DC when at full speed?Excepting the risk of it falling out (which seems minimal, plus I can see it through the vents at the side)is it safe/okay to be using this 220uF cap like this?(If you'd like a laugh... whilst experimenting with the capacitor and fan I forgot to watch the 10R power resistor which I was only intending to misuse as a 90W heater for a few moments... I was only alerted by the magic smoke coming from the melting plastic box it was slowly sinking in to.Cue quick transfer to emergency containment pie dish. FFS!)EDIT: Oh I see. It's not actually a 12V peak fan control output then but actually higher? So "full" speed isn't DC then, that'll be why the original fan still gets improvement from the cap even at full speed. Does that mean I need a 35V cap rather than 25V for more safety margin?

author: Photolunatic
author_rank: Contributor
timestamp: September 04, 2025, 04:36:14 pm
content: Hey folks,I’ve been battling the stock fan in my KA3005P—it’s horrendous. Even adding two Rubycon 35V 100µF caps in parallel didn’t tame the noise much. It’s PWM-driven from the Korad PCB and spits out ~20V with ripple that makes the fan rattle like a blender full of screws.Quote from: littleboot on February 28, 2024, 12:54:50 pmFollowing littleboot’s advice, I picked up theTS0702H 12V 0.8A DC PWM 2–3 Wire Fan Temperature Control Speed Controllerand paired it with anARCTIC P8 PWM PST Fan. It’s pressure-optimized, runs 200–3000 RPM via PWM, and should be a massive upgrade. The Arctic fan has a 4-pin plug with all black wires (3-pin are colour coded). I plan to cut the plug and solder directly to the speed controller or re-terminate with a 3-pin plug, but I need to figure out what pin is what.I know 5U4GB recommended the Arctic F8 TC with built-in temp control, but those are EOL now.Quote from: 5U4GB on February 29, 2024, 11:32:50 amQuestions I’d love input on:1. Is there a clean spot on the PCB to tap regulated 12V safely?I want to avoid pulling power from Korad's original fan header—it’s noisy and unstable.If internal 12V isn’t viable, I’m considering gutting an old router adapter (12V 1A) and wiring it to the 230V mains inside the Korad. Would this be a cleaner solution?2. Where would be the best thermistor placement spot?I’ve got the version with the updated radiator (like jewelie’s). The thermistor is the black epoxy blob in a metal eyelet with thermal glue. I plan to screw it onto the heatsink near the transistor.Any advice, schematics, or experience would be hugely appreciated.Thanks.

author: bateau020
author_rank: Frequent Contributor
timestamp: September 04, 2025, 08:25:18 pm
content: As mentioned in reply #27 in this thread, I took power from the 18V AC line, and added a buck converter. Safest, as it really decouples the fans from the rest.

author: Photolunatic
author_rank: Contributor
timestamp: September 04, 2025, 10:00:50 pm
content: Quote from: bateau020 on September 04, 2025, 08:25:18 pmThanks bateau020!One of thoseLM2596HV?

author: bateau020
author_rank: Frequent Contributor
timestamp: September 04, 2025, 10:15:17 pm
content: I used a bridge rectifier + cap + LMsomething DC/DC module, but the module you linked to would be great indeed.