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Can you please suggest an affordable low noise switching power supply please? I'm new and want to make circuits for audio.

Hello sir

Thank you for posting this! Bought the NANKADF 30V/10A power supply in january 2024 and am glad that it wasn't the worst buy out there :D

Great Review! Would you be able to test the protective contact of the power supply, i.e. whether there is no voltage on the housing in an emergency? According to my information, this can be a problem with cheap power supplies.

you said you have multiple hotplates? Can you recommend one that has a thermostate and actually heats the solution to the temp you set it? So you dont have to stand by all the time and watch if it doesnt get too hot? The Joanlab HS5C has on avergae good ratings but im wondering if you can get something cheaper or better at the same price....

Is it the 10A version?

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Your variac appears to be missing it's carbon brush wiper, that helps prevents arcing and short circuits between the windings. It looks like the brush contact part number for your variac is 146-0121-S. hope that helps.

It's probably a single pole double throw relay with two switches inside it, one which is normally open (the one without the magnet) and one that is normally closed (the one with the magnet). When both of the coils are energized the open relay closes and the closed relay opens.

The noise on he output voltage would concern me for the widest use. A liner power supply with fixed 3.3volt and 5 volt Terminas and an adjustable 0 to 30 volt output channel at even one amp would cover most work in the electronics lab, obviously adjustable current limiting on all channels is escentual. One of the things to look at on any bench supply is the output capacitance and how quickly the current limits, how quickly the voltage recovers and with what overshoot. Smps tend to have large output capacitance to reduce the fluctuations. Those big capacitors are just waiting to dump into your delicate masterpiece. Why not check out the above with your scope and compare with one of your linear supplies. I bet the peak output current of a given setting, say 100mA has a spike more like 3 times that and the voltage recovering overshoots by more than you would like, it would be interesting to see. I agree we are talking a budget psu here, but, two digits after the decimal point that are meaningless due to the output fluctuations may lead you to think it looks better than it is especially if the current limit is for all intense and purposes nothing more than protecting the psu itself.

Thanks for the thorough review and test

What is the green exit for?

Everything is so cheap on this unit I'm not sure the unit will last very long at maximum load. Why displaying 4 numbert when you can hold only 2?

I was loading mine with 12 V and 4 A for about 3 hours and the fan was turning on from time to time for around half a minute. You can definitely hear the fan. The ambient temperature was 25°C.

Is switching power supply is go for laptops repairing?

Probably find in a high voltage unit like that it'll be filled with sulphur hexafluoride or similar or left at ultra high vacuum. Sulphur hexafluoride is used to extinguish electrical arcs. Argon neon etc (noble gases) are used in neon lights and welding specifically because they are easy to ionise and carry an arc well. They may even pressurise the gas in the tube to help with breaking the arc though I'm not sure at what point the breakeven on that is. Vacuum makes things easier to ionise until you get to very very high vacuum levels, i don't know that it has been used for this kind of thing but i wouldn't put it past people. The advantage of that would be i imagine less leakage current than you'd get in a filled tube. Though that would rarely matter I'd think. Regardless of the fill gas they will almost certainly bake the assembly under the vacuum to like 300c or so to bake out all the water that has built up adsorbed into the glass surface and the metal etc. I wouldn't be surprised to see in a quality unit like this a getter of some kind too. A reactive metal that will eat any oxygen that gets into the tube. Though if it's pressured with hf6 that's probably not needed.

great video helped a lot

I have the same unit. You are correct, I don't think you could find another unit at this price point that has these features that all work so well. I used my dmm and it was ever so slightly more accurate than yours, which is more than enough for me. I am just a bumbling electronics hobbyist. I look forward to the day when I know enough and have progressed far enough to need something better!

9.978v vs 10v is just over 0.2% not 3%, thats really good, and at 30v it's 0.17%, I'm not sure how you could get much better than, I would say its very accurate. 2v noise seems huge though, is that definatly correct? I guess its just a peak at the very high frequency? Might be nice to give a noise figure in dB at say audio frequencies as that would be quite useful to know for a lot of uses. Also its a shame you didnt give us the ripple voltage as I can see you had it plugged into a scope. I like the look of these things but I would be concerned they would be noisier than a traditional psu with wound transformers and voltage regulators. They do seem very good value though.

Thanks for the review. Can batteries charge with it? Any reverse voltage protection?

That’s absurd! I generally like to buy good quality bulbs even for a cheap car, it’s a nice low budget luxury that I enjoy every time I drive at night

Thanks for the comments about the fan. I was worried that there's something wrong with my NANKADF power supply because the fan never started...

thanks great video. Could you do a teardown of it?

Nice work

Hi are you still happy with power supply?

Help!! Just got an oscilloscope and learned the importance isolating power supply from the same ground as the oscilloscope. What is the correct way to use a probe on this, the alligator clip on neg and probe in pos? How would this work in circuitly would i always keep the clip on the neg side of the circuit?

When will part2 be uploaded?

The cylinder at 7:42 is a getter container. It's just a stub inside that contains a material activated by heat(hence why it's so discolored, it was induction heated) that absorbs the remaining gases from the reference side after pumpdown, which is evacuated to an ultrahigh vacuum through the cold weld pinchoff(which you may have popped by prying through the hole, they are exceptionally fragile) - typically as high as possible, but the pressure is still recorded and calibrated for. These gauges operate around RF frequencies, the diaphragm/dual capacitor set being part of the coupling circuit, or the resonant circuit(varies by manufacturer). There's not much to it, but the physical design does get tricky. That's why the matched diodes are there. The heating bands are most likely to keep the physical structure, membranes, and the diode/opamp package at a constant temperature, since material properties change with temp. That's why the RF part sits in a clean desiccant can. There's basically nothing to see inside the gauge - it's assembled through welding, so you won't find anything besides a set of three rings welded together with a membrane between the two and the endcap on the end. This is however an advantage - capacitance gauges are extremely robust, and are very nice to clean. Just fill the vacuum side with acetone, swirl it around, rinse with DI water, then dry with ethanol and bake to ~50C(or just place under a vacuum immediately and evaporate).

The square hole behind was meant for a USB connector, enabling the PSU to be connected to PC for remote control, that’s what I heard. I’m planning to get one that is 120V 3A for my work though. Btw, the brand i meant was Wanptek, which has a very similar design to what you have there.

I love putting group 24 batteries into all my vehicles. they are good for v8 trucks, suvs, and I even put them in my four cylinders. I usually can squeeze them in and they just are awesome and cheap.

The square hole in the back is for a power switch. Mine has one as we as the soft button on the front.

ty i refuse to pay 150 for a battery if there are other options like this. also why couldnt u just flip the battery around so u didnt have to stretch cable?

Nicely done. Subbed.

Output button is just a knob, that cuts off positive wire from connection? Or I'm wrong?

This power supply does not operate in constant current mode.. It does, however, demonstrate the ability to set an upper current threshold limit. Were this able to operate in a constant current mode, for example, shorting the leads and adjusting the current to 0.001A ie; (1 milliamp)- and thereafter connecting a load of 1000 ohms across the (+) and (-) output terminals SHOULD indicate 1 volt. It does not. I own this same power supply, albeit it is the 60V/5A model. Let's say the load is actually 1234 ohms rather than 1000 ohms, therefore this DC power supply supply should (and this equipment does not) slew the voltage across the load to 1.234 Volts. In my experience this manufacturer supplies (no pun intended) a solid product meeting the OEM's specification. The constant current foible I examined seems honest and attributable to the vagaries of the Chinese (Mandarin?) languages translation to English. This OEM even included a very nicely attempted explanation of how to set the power supply upper current limit threshold.. I believe many technicians and technologists are not typically exposed to 'Constant Current' functionality in higher-end bench power supplies (Agilent, Lambda, etc) while the verbiage 'constant current' has been heqar bandied about by more senior staff. Another term for 'constant current' is a 'force-and-measure' type circuit which seems more common in the EU and large corporate development labs. Mr. Peterson provided a very professional presentation here and should be commended.

ruclips.net/video/mmsBT3Fuggk/видео.html i think a lot of that is all about getting a clean reference so that you get that nice solid signal out. Here's a video by a self proclaimed volt-nut which you'll probably enjoy pretty well. Cheers!

Super! Thank you very much!

words of wisdom , if/when your vehicle needs a new battery , they cannot be "reconditioned"/"renewed" or any of that wishful thinking , get the best correct battery you can afford asap , a weak battery or carrying around a jump box/cables is a pain as well as risky to your vehicles entire electrical system , this is coming from a 63 yr old full time mechanic friend of mine whom i would consider an "expert" on the subject , IMO ;-)

58R means it has reverse terminals. Was there a regular grp58? How u make it last longer is slow chg it before u install new one.. Also, ur terminals were dirty. Shorter battery, leas plate surface, ur sacrificing reserve capacity & CCA's.

Very cool, I wonder if you share source code