4PCS AC/DC to DC Step Down Buck Converter AC 5-30V DC 5-48V 24V 36V 48V to DC 2.5-35V 12V Voltage Regulator Board 2A Adjustable Volt Power Supply Module

After reading the reviews, I carefully inspected mine for any manufacturing defects, and it seemed well enough put together (none of the components were on very straight, but everything is there and the solder joints look solid). I put a small load on it (1k resistor, I think) and clipped my volt meter to it and applied a ~12VDC voltage to the input lines (since I only have DC on my bench). It came up around 4 volts by default, so I cranked the potentiometer a few turns -- it's multiple turns per volt, so very precise -- until it read 5.00 volts, and there it stayed over a wide range of (DC) inputs. Later I connected it to an ESP32 dev board, and the hot end to 24VAC, and powered it up. Despite totally different input and load, it still read 4.99 volts so I gave it the tiniest tweak and now it reads 5.00 every time I check it. I also checked it recently on a little oscilloscope and if there's any ripple it's not visible to the eye against the 5 volt displacement. So, no complaints at all, other than that it's a little bulkier than I probably need for my application. (I'm running the ESP32 w/wifi, and up to 6 relays on it; no problem.) I will update this review if it fails; if I haven't, assume it's still working. It's on 24/7 from the date of this review. (Now what to do with the other 3... Sprinkler controller?)

Works as designed, used for converting ac power to dc for a o gauge train project.

Like others, I use these to convert my landscape 12 VAC to a 3-5 VDC for powering LED strings that are battery or USB powered. Does a nice job of going down to about 2.5 volts so you can lower the intensity of LED if you choose. I chose small boxes with 3/16" glands to route wires in a sealed manner.

I was stepping down 48v DC to 12v DC and after about a week of operation I noticed my output was reading 0.0V. Guess this is what happens when you buy the cheapest electronics off amazon.

The LM2596HV is a great chip for building a buck converter, and this particular product is pretty much an exact implementation of the reference design. So, I would expect good performance overall. Much to my surprise, that wasn't at all the case with the first board that I took out of the package. No matter how I adjusted the precision resistor, the output voltage always equaled the input voltage. That's not good at all. In fact, that can do a lot of damage to anything connected to the output terminal block.I tried to check for problems. and as the adjustable resistor readings were obviously bogus, I removed that part and replaced the component with a known-good resistor. Same results.Next, I closely inspected the board, and the problem quickly became apparent. The integrated circuit is a through-hole component, and despite being soldered from the bottom, there were giant blobs of solder on the top side of the board shorting out the pins. After cleaning up that mess and redoing the soldering, everything works now.Overall, I like the board. The price is good, and the LM2596HV does exactly what I want it to do. But there apparently is no quality-control at all. Not only can't I even begin to guess how so much solder made it to the wrong side of the board, this particular mistake would have been blatantly obvious the moment anybody tested the board. The buck converter wasn't even doing anything at all.Considering the price, this is still a fine purchase. But expect to have to rework the boards. And whatever you do, don't connect them to anything until you have fully tested them.Edit: Found another buck converter in my set that clearly should not have passed quality control. I was missing the terminal block for connecting the wires. Easy to fix with a soldering iron, but that should not have been necessary.

These are not suitable for audio use. Introduce a lot of noise (in the form of a hum). Tried for be sure all was properly grounded and that did not help. Would need to put a filter in the circuit. I was attempting to use to convert 24VAC to 5VDC for a bluetooth audio adapter. Fail. I will now be using (although a bit more work) a 110VAC to 5VDC and leave the 24VAC circuit alone.All of these I tested seem to be predisposed to produce under 4VDC output. You will need a multi-meter and a small screwdriver to turn the voltage adjustment screw to get to 5VDC.

Using these to convert 12V AC power from my landscape lighting system to 5 V DC to run the led lights in some pool umbrellas. There is a little reostat on them you can turn with a screwdriver and turn the output voltage up and down a little bit to tweak the output. Super nice!

I wanted to connect an LED candle to our landscape lighting to light up a statue (the character is holding the candle). I could not find a candle that is natively 12V and the coin batteries in the LED candles I could find are 3V. This worked perfectly for that purpose.A bit more technical detail: I bought weatherproof LED candles that take CR2032 batteries. I opened them up, cut the wires to the battery, and connected them to a short piece of 16-gauge wire, then connected that to the main wire of the landscape lighting system. I sealed the LED candles back up.Landscape wiring is typically 12V AC (the transformers put out AC, not DC).You can adjust the output voltage of this converter by using a small screwdriver to any voltage within its range. I used a multimeter to check the output was exactly 3V.I bought this weatherproof housing to hold this converter: https://www.amazon.com/gp/product/B07H5C8BB6This converter has been running perfectly for a month now. I will be using another one for a similar purpose.