KORAD KA3305P - Programmable Precision Variable Adjustable 30V, 5A DC Triple Linear Power Supply Digital Regulated Lab Grade

I bought this power supply for 3 main reasons.1 - Being able to turn the power to the leads on and off without turning the whole unit on/off2 - Having a memory function that acts like your car radio recalling settings you saved earlier (both outputs share the same 5 memory settings)3 - You can combine the two outputs into one output in series (gives you up to 60V at 5A) or parallel mode (gives you 30V at up tot 10A) on one set of leads4 - These features and the flexibility they provide make this a very good bang for the buck power supplyThere are other positives, 2 digits after the decimal place, multi-turn knobs, easy to read display and the quality feels pretty good to me.Some things could use improving, as a previous reviewer mentioned the supplied leads are low quality, the stock fan is a little noisy although it is variable speed, the button pushing and knob turning to set the parameters is a bit . . . . non-standard?For me the user interface was not a big issue and the payoff for learning how it works is that you are very unlikely to bump a knob and accidentally blow something up.Best feature, beting able to adjust the volts and amps while the leads are connected to my project THEN turn the power on to the project. I was surprised to find some power supplies that had the on/off feature but didn't let you see the settings when the button was not "on" which is almost useless to me.the KA3305D is not perfect but, I think it's very capable and when you factor in the price ($185) it's 4,5 stars, I would buy it again.

As an analog and digital design engineer, with advanced degrees, I am used to high quality HP, Tektronix, Fluke, Lambda, etc. lab equipment. I just wanted to buy something that was adequate, for short term development work, as I am coming out of retirment to return to consulting. If that works out, here in Florida, I will buy high quality power supplies again. Orlando, and surrounding area, are not the hot bed of technology and development that I was used to in Silicon Valley.When I turned power on, the display on both sides read 30.05V and 5.02A. After pushing a lot of the buttons, nothing happened. Then, it briefly seemed to work. I could turn the voltage adjust knob, and the left output would change properly, in 1 volt increments. Paused to attach my 4 1/2 digit HP Multimeter, and it confirmed the power supply voltage reading was correct, around 5.01 volts.Then when I turrned the voltage control knob, something strange happened. It went to 00.07V and 2.056A, on both meters, and would not change! Pushing all 10 buttons, and both knobs had no effect. On-off cycling numerous times, and no change. Desperate, I grabbed their CD, and found the sleeve was slightly wrinkled. That suggested that they had sent me a used or returned unit!Undeterred, I loaded the CD, but was unable to read any details. Word, Notepad and all other programs were useless! That was the last straw. Boxed it back up, and am returning it to Amazon.Conclusions: The supply had promise, but was DOA. Played with the controls enough to decide that the memory stuff would have been a wast of time. Their instruction book did not provide the necessary details to use their program controls. In all my 30+ years of design work, I never needed those features. Typically, you confirm proper operation at the extremes of voltage, temperature, humidity, etc. In real life, system voltages drift slowly, have ripple, and induced spikes, etc, and are tested for separately.Bottom line, with the push for lower operating voltages, who needs 30V and 5A anyway? I would have been very happy with a lower output power, and a reliable supply. So, I ordered a single KORAD KD3005D supply, for $85. It also has 30V and 5A, as most seem to now. If it works, I will order another. How often do we need a fixed 5V supply anymore? Even logic is going from 5V to 3.3 and below.My guess is that the supply I received and been returned to Amazon, and then reshipped without being properly tested. The returnee may have damaged the supply, and not told Amazon.Thank goodness that Amazon is so amazing about accepting returns. That is why I keep buying from them!

I read other reviews about the difficulty in adjusting the settings on the unit. It definitely is not as intuitive as you would prefer but after a few minutes you realize that a lot of flexibility is packed into just a few controls. The current and voltage meters on the instrument seem accurate enough for most bench top uses. I also like the series and parallel output modes which doubles voltage or current capabilities of the unit in a single output. The constant voltage and current settings are ideal for the applications I've tested with so far. The specs also calls for a remote measurement terminal that compensation for the voltage drop of the supply wire but I haven't found how to use this capability. It is a nice feature but not one that I need at the moment so haven't continued to investigate. When the unit arrived I was excited to test it out. I found that the output voltage only reached ~22v no matter what I did via the cotrols. The CV setting could be adjusted to the rated output voltage but the actual voltage output was much lower. It turns out that the AC input voltage switch was set to 220v. After switching it to 110v the rated output voltage was met.I am totally pleased with this unit. Considering the flexibility and functionality of the unit the complexities of controls is worth it. Just keep the manual handy for the first few times you use or for seldom use of certain features. Also the memory recall feature is nice but just be careful that you don't accidentally hit one of these buttons while connected to a circuit that could be damaged due to higher voltages of another memory button.

One Star!!Amazon warehouse deal gone wrong. Not sure if this is a good product. Wasn't able to tell. She's dead Jim. DOAUPDATE: 4 Stars nowI ordered a second one and it seems to work well. Its intuitive an easy to use but Im Not sure how accurate the voltage and current readings are in comparison to the displayed values. I don't have an accurate enough meter, and the meter i do have is showing a 50mV discrepancy at 19 Volts. A solid bench Multimeter will be my next purchase. Ill update with better results then.

All adjustments change digits as described in the manual, but output voltage is 0 on all channels. Shipping it back. My other Korad PS works well..