DC power supply (0-30V,0-5A) adjustable, switching power supplies, mini high precision 4-digit display with USB fast charging interface, variable lab bench power supply, output on/off/encoder knob

This power supply really looks the part. It’s compact and lightweight, yet seems well built. The digital display is easy to read and the adjustment system is intuitive. My one criticism of the display is that the green/red CV/CC/OUT indicators are a bit dim.I’ve run it briefly at 6 A / 20 V. It didn’t complain.I’d say the voltage accuracy is ±0.1 V or better. At first I was nervous about using it to charge Li-ion cells, so I set it to 4.1 V and checked with a calibrated multimeter. The charging current tapers off nicely and I’m now confident about the CV mode.The fan is noisy and has only one speed. Variable speed would be better. But at, say 3 A / 12 V the fan comes on infrequently. At 1 A / 4 V it kicks in just occasionally for two or three seconds.The mains plug fits well: neither too tight nor too loose. And the mains cable is nice and flexible, unlike many.Inside, all is very neat. Like another reviewer, I was a bit dubious about the earthing of the outer metal cover because of the thickness of the paint. I used sandpaper to ensure a good contact.The supplied DC leads are better than I’d expected from other reviews, and the screw terminals too, though I agree that a through-hole would be nice. I will not be rushing to change the terminals.One of the encoder knobs fell off and I had to glue it back onto the shaft.

I could have gone straight to China for this paid £20 less but would have to wait and been at the mercy of customs & excise plus if it was not accurate or something else is wrong you really do not have a leg to stand on but back to the goods, everything about this appliance is spot on its a top machine I can power my bits and bobs on the bench and get great spot on readings when testing multimeters small motors and a host of bits and bobs it's so easy to use and takes up very little space, I did read the bad reviewes but took a punt because of the 5.4.3. Star reviews and I can only think 🤔 that they got the odd bad one or abused it and blamed the manufacturer process but me happy as Larry with it I also to out the extra insurance just in case 😉 only one complaint and its minor the crocodile clip leads that come with it are poo 💩 so they went in the bin,, I treated the machine to a set of decent leads that are able to except 1000v (I know over kill) nice and pliable silicone that the very minor complaint I had.

I bought this (the 10A version) after reading both positive and negative reviews, noting the reviewer who pointed out that many reviews were for free product so I'll say up-front that I did NOT get this for free, nor did I get any incentive to review it, favorably or otherwise.Addressing the criticisms I've seen first, in descending order of importance from my own perspective:(1) Noise: [updated]One reviewer said that the output had noise on it; I checked (off-load) with a 'scope and yes, it does. Fast switching transients, most of it is under 200mV peak-peak in amplitude, with a max of perhaps 400mV peak-peak, at different frequencies. This is quite a bit for low voltage o/p. Switching noise hardly a big surprise on a switching power supply, but because it's very fast transients, it is quite hard to get rid of. As you turn up the output voltage, the spikes don't increase in amplitude but do become more frequent. The manual quotes max ripple (current) of 0.5% and "voltage stability" of 0.5%. The fundamental output voltage seems absolutely rock steady, to be fair, but the noise is relatively fast impulse type noise; while the pattern of successive spikes is some syncopating mix of switching frequencies, in the region of tens of kilohertz, each spike is sharp-edged which means overall it's an episodic pattern of, in effect, very high frequency components. On my 'scope I see a rapidly diminishing "ringing" at about 450KHz, halving in energy every cycle and negligible after about 5 cycles, for each spike, so the 200mV spike lasts about half a microsecond according to my (slowish) 'scope but is probably in reality much shorter, and the ringing is probably on the connection wires. I initially thought that typical decoupling and other load capacitance would soak this up, but the sharp pulse edges instead get everywhere. Linking the -Ve output terminal to the centre ground terminal seems to help. I opened it up to take a look - there are no ferrites in the output wires, nor did I see any chokes near where the output wires leave the main board. I've docked a star because while I like the way it looks and works, I'm going to have to make some modifications to try to reduce the switching noise.(2) Mains cable being loose.I thought the reviewer who said this must have had a dodgy cable. Then I plugged the one supplied in and thought maybe they had a point, but then I realized it wasn't fully home. When plugged in, it feels like it's gone all the way in and is loose. It has another 5mm or so to go - push it firmly past this stiffness and it snugs into place and is nice and firm, at least on my one.(3) Control convenience:A YouTuber bought one of these and complained that when the output is switched on, adjusting the voltage also sets the current display into "entry" mode so it shows the preset current rather than the metered current. It goes back to "live" readings after a couple of seconds hands-off. (To make this clear - you adjust voltage and current with the output switched off and the voltage is what it will output, and the current is the current limit you set. Once the output is turned on, the current and voltage displays go "live", so if the load is drawing less than the preset current, that is displayed, if the load is trying to draw more than the preset current, the current will be close to the preset and the voltage will have dropped to keep current below the preset. If you're within the limit, though, the YouTuber reasoned that the thing should continue to show live voltage and current when adjusted with the output on. That way you can manually adjust voltage to achieve a desired current. For me, this is not a use case I care about - if I want to monitor the current in real time while adjusting the voltage I can just use another current meter, but mostly I'm only interested in setting a current limit that will prevent short-circuit damage.Another control feature is that while the device remembers the presets when you turn the unit off and on or unplug it, by default it always starts in output-off mode. This, to some, is an inconvenience because it means you can't leave it unattended as the sole power of something that you want to be on all the time, because a slight blip in the mains supply will cause it to reset and turn its output off. To me, though, for a bench PSU this is the way I want it to work, especially if there are people around who might have fiddled with the voltage etc while you weren't looking. At work, we have a bench PSU that comes on with the output in whatever state it was when switched off, and a couple of boards have been blown up by people turning it on connected, after someone else has left it set to a high voltage and output on. For me, then, this one works the way I'd want it to. HOWEVER, this feature can be altered via "system settings" - see below.The only other "user interface" thing I think might be of concern to some is the bleep on startup. I actually, unusually for me, looked at the manual to see if this could be switched off, and found somewhat to my surprise that yes it can, there are a number of "system settings" you can get to by a long press (5 seconds) on the output switch. System settings are as follows:1. Machine ID (see comms)2. Output state on power-up (so it can come on in "on" or "off" state)3. Screen brightness4. Buzzer mute (yay!)5. Comms baud rate6. Comms little- or big-endian.The comms features are for an option serial module that allows remote control - again, bit of a surprise, this.Personally, I'm totally happy with the defaults, except perhaps the bleep (though it's not that obtrusive).Features, observations, summary:As others have said, the output voltage seems accurate, certainly by the standards of regular hobby- or professional-grade meters and the like. Someone with lab-standard high-resolution calibrated meters might find something to complain about, but I would consider it "good enough" for any normal purpose. The number of decimal places for the current display might be a bit specious, I daresay it's not actually accurate to a milliamp, but it's not something I care enough about to check.The way it operates seems exactly as I'd like. Sure, they could have done more with bypass capacitors and ferrites and things to get rid of the leftover fast switching noise, but any load you're likely to connect will likely have its own supply caps or not care, or you can take steps to deal with it. The output is WAY more clean and stable than many a typical "wall wart".Neither of the output rails is tied internally to the centre ground connection (which I assume is tied to mains/supply ground). I.e. the output is floating. It's worth noting that the output becomes somewhat smoother if you ground the -Ve side.The output posts are screw clamp types but quite thin and lacking the sideways hole for wires that many of these types of posts have. The external part of the post is only about a 5mm diameter despite having a 4mm hole down the middle to take banana plugs. If that bothers you enormously then I daresay they can be replaced with better posts. (They mount with what look like 4mm screws with nuts on the back and should be easy to change.)The supplied croc-clip cable for the load side is OK but thin, cheap-n-cheerful, I doubt mine will see any use.The unit is light, but not as "tiny" as some reviews suggest - it's not big, though. The dimensions are given in the description. If you stacked six standard DVD boxes together and stood them on their long edge they would be more or less the same size as this unit.I have not tested the over-current protection, nor indeed its ability to supply the rated current. Mine allows output voltage to be set to 31v and current to 10.2A (I bought the 10A version, which at time of writing was about £14 more than the 5A one).The build quality seems really good, and it's noticeably fuller-featured than I was expecting, what with the system setting options and the optional serial comms remote control module (OK, I have no idea how you could get one but I'm willing to bet it'd be easy to hack a DIY one after a bit of a poke around inside. The facility to remote-control up to 32 of these from a single serial interface must be handy for someone!)[update] I have now had a quick look inside to see if extra suppression could be installed, and it's as neatly made as shown in the photos. The earth connection from mains inlet through to the ground post on the front is reasonably convincing, taking in various fairly generous ground planes on the main board via a couple of metal mounting brackets which appear to be meant to also ground the metal case. However, the powder coating on the inside of the case meant the case on mine was not in fact earthed. I scraped the coating off around where one of the brackets sits so that the case on mine is now earthed. When I dismantle it again to try to improve noise suppression, I'll also scrape the case around the other earthed bracket, replace the terminal posts with better ones and probably uprate the output and ground hook-up wires.This review is way longer than I originally intended but overall, I'm pretty impressed with this thing.

What a brilliant piece of kit it's a must have in your tool shed or garage I've powered and charged a couple of items 1 being a ebike battery once you set up the volts, ah, the rest is simple it monitored the charge the whole way through and kept it protected through out and the size of the unit itself is great I can just pop it on a shelf when not in use I actually charged my mobile phone from it at the same time and it was charging very fast if you're looking at these don't hesitate it's a good unit.

Seems well made.Works very well.Has all the features you need, like Output On/Off.No fan so is very quiet. Display is sex on a stick.Only very slight complaint is the terminals are on the small side (not very deep).5 StarsAdded commentsStill very impressed. See oscillogram attachedThere is no overshoot !There is a delay of just over a second before power is applied, but, that is not a problem for me.The voltage ramp up is around 180mS, again not a problem for me.The output control is obviously not a contact on the output, it's controlling the regulator. Which seems to work well.The display is very accurate and good resolution.All round incredible value and a great buy.

The unit seems goodLow ripple on the supply the current limit works well at values I testedThe annoying bleeper can be stopped (all in the manual) for the price seems to work for meDo like it having a separate out switch which not all bench units have