LONGWEI DC Power Supply Variable,30V 10A 4 Digital LED Display Adjustable Regulated Switching Power Supply Digital with Leads Power Cord Used for Spectrophotometer and lab Equipment Repair (Black)

FINAL UPDATE (Hopefully!: I have now been using these 2 supplies for around 4 years and have not had a lick of trouble with either of them. They run very quietly, are very accurate and hold their settings perfectly. I would still recommend swapping out the amperage potentiometer for multi-turn (as long as you are OK with soldering) but it's still a great power supply without it. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ I really like this power supply. One of the main reasons i bought it was of course its price, but the reason i chose this over the other cheap ones was that, from the reviews i saw on YouTube, the others often seemed to have trouble with the Volt/Amp potentiometers (control knobs). They always seemed to be cheap single-turn ones that failed pretty soon.....and that's why i liked this one, because i knew that the Voltage control pot was multi-turn, and hence was definitely better quality. I am only a real newbie at electronics, but i had learned at least enough to know that. The Voltage pot IS multi-turn and it is easy to get it tuned in very easily. I have seen other guys struggling to tune in the Coarse/Fine pots on other supplies. The Current pot on this one, however, is NOT multi-turn and i wish it was....but it's still smooth and easy to work with. The calibration seems spot-on out of the box, but i know that i can fine tune it if need be from the trimmers inside, so no worries. UPDATE: I just purchased a second one of these and checked it out internally.....it is VERY easy to upgrade the current (amps) control to multi-turn also. I see they are 10K pots (WXD3-13 2W 10K...Google it) and i just purchased ten of these for $13 from Ebay and will be installing one in each of my power supplies' current contol. It's not a big deal but for $1 or so then why not? The other main reason i chose this one was that i saw how the other cheap supplies have the BIG flat heat sink aluminum plate slapped straight across the air flow towards the rear of the case, so all the other components get fried at the expense of the main chip staying cool! That seemed awful design to me. This chip has plenty of cooling (on nice proper finned heat sinks) but so does everything else because the main board is set parallel to the case so gets plenty of air flow. The fan cuts in and out under thermal control, except it does a quick self test upon power-up. The only thing i would wish here is that the speed could also be thermally controlled, but that is nit-picking and i could modify it myself anyway later if needed. The fan does NOT seem unduly noisy when it does come on and is not annoying to me. The voltage actually runs up to 31.9 volts and the current to 11.4 amps, so you get plenty for your money here. For newbies (like me!) to set the current, you have to short out the croc clips while at a low (4 to 7) voltage. After that, upon applying your load, the current will gradually increase as you increase the voltage....until you hit your set current and then it will switch to constant current mode and only the voltage will increase. OK, i will quit teaching the experts how to suck eggs here and leave it at that. In my view, this is an EXCELLENT power supply. The only reason i have taken off one star is because 5 stars would be "perfect" and since that doesn't exist, i have taken one off for the above nit-picky points. There aren't many reviews online of this power supply so i wanted to help correct that. My supply has worked faultlessly since purchase but that has only been a week, although i have tested it pretty rigorously in that time. If anything should change regarding my review, i will make an update here to let people know. I was going to purchase this on Ebay but then noticed it on Amazon for only a couple of dollars more, so i thought it was worth that to get the better "returns" peace of mind because with my Prime membership they will pay the return for me and i can also try it free for a month and, if i don't like it, i can return it for any reason. And no, Amazon don't pay me for this! Lol! UPDATE OK It has now been around 10 months since my purchase (just bought a second one!) and just wanted to say that there has been no change to my assessment. This power supply has been great in use and has never given me a problem. Just for those (like me) that worry that the thing might blow up after a month or two, it has never given any hint of a problem, and some of my usage has fairly put it to the test. OK...that's it. I will update again if this changes, also. UPDATE2 I have now swapped out the current pot in my supply for a 10K multi-turn pot and it is now a SUPERB power supply! It really has made a huge difference for the cost of $1.30 per supply. I highly recommend this modification AND the supply. UPDATE4 (3 was at the beginning) Six years now and counting. This thing is now perfect with no issues at all. I have now updated the stars here to 5 stars....it's perfect.

I've been using this supply daily since I've received it. I've charged sla batteries, used it to test a suspected faulty truck blower motor, charge lithium ion and phosphate batteries, and power a few high power led lights for testing, along with anodizing some titanium parts for fun (large and small). I have to say I'm more than satisfied. The voltage display is adequate, though the voltage is in 0.01 increments (if you're gentle and patient), to overcome the limitations of the display I simply piggy back a trusted digital volt meter no big issue there. Ive observed the voltage is satisfactorily stable all the way up to its 10 amp limit. I believe the unit is actually pretty well overbuilt as well, as I've had no issues drawing the full 10 amps, and a bit more with no overheating issues. The fan is temperature or load responsive and only runs when necessary, so no constant noise, and when it does run its not annoying at all. I haven't opened it up yet to observe the build quality, but only because I've been satisfied and impressed so far. The included test leads are also a surprise, I was fully prepared to build my own to replace them, but once again I've been adequately impressed by them as well. So, all of that to say its a solid little unit for the money and does everything its supposed to, and does it well.

I like like being able to bench test parts, having a variable DC power supply at this price was a good option. It seems to be accurate and made well. I wish there was an output button so the voltage and current could be set and then applied. Instead you need to turn the unit on and apply an unknown supply and then bring it into adjustment. This can potentially damage some components under test,. Best option is to adjust it with no load, switch off, connect part to be tested, and repower.

Great small, but full feature power supply. I bought it to run my HO Slot Car track as it’s the one featured in Viper and other YouTube videos for their tracks. Using it right now to charge my wife’s dead car battery. Car hasn’t been driven in over a year, as she had consecutive knee replacement surgeries. I let it slide. The charger is quiet, cool and easy to use. Moreover, it comes with several very useful connectors. I have a high power jump battery pack but the car battery was completely dead, so that wouldn’t work. It is fully protected for over voltage, current, and heat. Humming along at 13.8V and 6amps right now for two hours. Unit has no heat issues and is very quiet. I’m happy.😃

This was a replacement for one that went bad. All works as it should.

I used this intermittently over a period of maybe a year. Probably less than 20 hours of actual operation. Then it sat on the shelf for a couple years. I turned it back on to do some water splitting (electrolysis) for chemistry class demo and it worked great. I turned it off and now I can’t turn it back on again. No display. No fan. No voltage or current. I swapped out the power cord, tried different outlets, let it cool down (although it was only very slightly warm). Nothing. The next day, I realized all of the outlets in the kitchen were without power. I checked the circuit breaker and it was not tripped. Then I realized there is a GFI in the kitchen that had tripped. This is a great power supply.

This thing was dead in the water right out of the box. No lights, no fan, no nothing. Didn't even come with any instructions of any kind. I am returning this junk tomorrow only because the return center is closed tonight.

Great buy especially if you plan on running various sized cars that require different voltage . I use this on a digital Carrera slot car track and everything functions better vs a power pack .

Está muy bien

The product is damaged

excelente

Cumple

No trae los banana plug, lo compre por eso, que decepción, espero que funcione al menos