Who does it? - Page 1
Forum section: electronics / testgear

author: Jasonbit
author_rank: Regular Contributor
timestamp: August 22, 2018, 08:40:07 am
content: Hello folks,I don't find difference between this two product:RND 320-KD3005D(https://www.reichelt.com/de/en/laboratory-compact-power-supply-unit-0-30-v-dc-0-5-a-dc-rnd-320-kd3005d-p212040.html?PROVID=2061&rnl=en342018&nldnt=3Dfrbnih&&r=1)andRND 320-KA3005D(https://www.reichelt.com/de/en/laboratory-power-supply-0-30v-0-5a-stabilised-programmab-rnd-320-ka3005d-p212041.html?r=1)I was compare two "Product Description" and "Technical Details" and it seems to me that they are exactly equal, less at these points:RND 320-KD3005DQuoteRND 320-KA3005DQuoteI marked the lines that looks the same to me with label "(check)". What do you think about this two product? Which difference exist between them?Thanks

author: capt bullshot
author_rank: Super Contributor
timestamp: August 22, 2018, 08:53:25 am
content: The difference is clearly visible in the product pictures: they have different controls (knobs and buttons). Otherwise, it's the same Korad crap. Don't buy it.

author: Jasonbit
author_rank: Regular Contributor
timestamp: August 22, 2018, 09:03:02 am
content: Quote from: capt bullshot on August 22, 2018, 08:53:25 amThe difference reside in visual and usability. Sorry, I feel like a fool to disconsider this aspect on first impressionExist another solution in range this price? What models do you suggest?Thanks

author: capt bullshot
author_rank: Super Contributor
timestamp: August 22, 2018, 10:57:52 am
content: Quote from: Jasonbit on August 22, 2018, 09:03:02 amI don't think so. I wouldn't expect to find a "good" power supply in this price range, but the definition of "good" is variable with your personal expectation. In my experience many lab power supplies are crap in one or more aspects, it's really hard to find one that meets my requirements. Your experience may be different.Disclaimer: I bought one of these some time ago (the KD model) , blinded by its low price tag and impressive output power capability. I was disappointed from the first moment on by various aspects including usability. Otherwise it just did its job on occasional use.One model I'd recommend might be the Toellner TOE 8852-32 or its older variant (don't know the model number) having 10-turn pots instead of the digital encoders (I'd prefer the pots over encoders). Buying such one new is out of scope, if you're lucky get one for 300 ... 400 EUR used. Others might suppose quite a variety of older HP lab power supplies.

author: Jasonbit
author_rank: Regular Contributor
timestamp: August 22, 2018, 11:05:45 am
content: Ok, but I don't expect a good and spectacular product on this price! I think which you compare a products in different ranges!What I want know is what it is difference in this two products (beyond the question of usability) and if this product it is a good investment whereas in this range price!Thanks

author: Zucca
author_rank: Unknown
timestamp: August 22, 2018, 11:14:10 am
content: Buy a used old Agilent/HP one from Ebay. They last forever and you have the schematics if something happens.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 22, 2018, 11:25:34 am
content: A model similar to the KD model has been sold by Dave and it tends to get positive reviews by its users. I have a two channel model and enjoy it.

author: Pinkus
author_rank: Frequent Contributor
timestamp: August 22, 2018, 12:30:26 pm
content: While I usually rely on my Rigol DP832, I also have two 2-channel-Korads with 5A each channel in my workshop (purchased from the nice guyToploser) as I sometimes need 30V with up to 20A. I cannot say anything negative about them -especially for the price-, even at high loads they work without problems (though the high noise caused by the fans at high load is ... well... impressive).So if you are on a budget, I would get the RND 320-KA3005D as it comes with 5 handy memory places.The memory feature is the only feature I do not like this much: they do not have an user-save-option but saves the current state always automatically to the memory place. So if you clicked on M1 to get your 5V, 100mA (which you programmed before as you often use this) and you then move the current to 200mA to check something, M1 is from now on set to 5V, 200mA, even if you just want it to be temporary. I would rather see a user save mode only, where you press Mx for >1 second to program the current setting to the memory place. As this is how 99% of all devices in the world are working with memory settings, I call this "strange behaviour".I sent this idea of a user save mode to Korad a few years go, but they were not interested. Maybe some strange Korean logic. Go figure.If you have enough space and if you are not on a tight budget, I would follow Zuccas advice and find a used HP / Agilent power supply.Btw: you are using a very strange, non descriptive thread title. I would vote to modify it to "need help in finding out differences in Korad power supply" or similar.

author: Fungus
author_rank: Super Contributor
timestamp: August 22, 2018, 01:01:53 pm
content: Quote from: Jasonbit on August 22, 2018, 11:05:45 amYou really can't see any difference between them? None at all?

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 22, 2018, 01:10:33 pm
content: Quote from: Pinkus on August 22, 2018, 12:30:26 pmI have the same model and same experiences, except that I don't have much trouble with the way the presets work. Having to save the actual settings might be more convenient, but it works well enough. Setting voltage and current is also easy, the easiest of the power supplies I've worked with so far. If you need cheap and decent power, they're great units.

author: Jasonbit
author_rank: Regular Contributor
timestamp: September 03, 2018, 05:13:27 pm
content: Thanks to yours reply.Please, say what do you think about my conclusion:my final opinion is that for a source of this value is a good investment. I am still learning and so my knowledge is not too vast to know how to distinguish things well or to decide for an article on ebay, as it was said, about Agilent / HP.I'm trying to figure out the differences between the KA3005D and KA3005P models. The difference I detect is that the P model has the USB connections, RS232. That's the only way.KA3005P:https://www.reichelt.com/de/en/laboratory-power-supply-0-30v-0-5a-stabilised-programmab-rnd-320-ka3005p-p212042.html?&trstct=pol_7KA3005D:https://www.reichelt.com/de/en/laboratory-power-supply-0-30v-0-5a-stabilised-programmab-rnd-320-ka3005d-p212041.html?r=1For what kind of material and works will I need the USB, RS232?Note:https://www.youtube.com/user/EEVblog/search?query=KA3005

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 03, 2018, 08:10:39 pm
content: Having computer control is great for automated testing. If you build a SMPS and want to know its efficiency across various voltages and currents it's great to have a program that does that for you.

author: Jasonbit
author_rank: Regular Contributor
timestamp: September 04, 2018, 09:58:55 am
content: Quote from: Mr. Scram on September 03, 2018, 08:10:39 pmHoo this means that I can build a script that I connect on the computer (through usb or RS232) and turn/command the power supply over several levels of voltage and current. This to sweep a particular board to the various lde on and off with different power levels. Right?Thanks

author: ThomasDK
author_rank: Regular Contributor
timestamp: September 04, 2018, 11:16:55 am
content: I have the RND 320-KD3005D.It has the same fan issues as the rest of the Korads, so do yourself a favor and get a new fan with it if you buy one.The PWM signal makes the fan buzz loudly even when it is not running, it drove me crazy.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 04, 2018, 11:36:17 am
content: Quote from: Jasonbit on September 04, 2018, 09:58:55 amCorrect. Ideally you'd combine the power supply with a computer controlled electronic load to get the full picture. That's obviously just one of the options. Some people just like the remote control option. Be sure to look around the Internet to see things work the way you expect them to. Some people have written their own control software for the Korad power supplies.

author: Jasonbit
author_rank: Regular Contributor
timestamp: September 07, 2018, 01:40:17 pm
content: Thanks guys ti your all advices. The equipment about to arrive soonThan I will post reviews!Best Regards and thanks for everything!