UMLIFE 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

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.

Two stars only because after I fixed everything they worked as expected (but not as advertised).First off, it specifically says in the description that this is built with the LM2596-HV. This is good to 60V input voltage. However this is not true. It actually contains the LM2596T-ADJ which only specifies max input voltage of 40V. This pretty much makes the rest of the specs listed false as well since this buck IC is the centerpiece of this unit. I didn't need the HV input since I'm using these for 24VAC industrial control, just be aware of the sketchy advertising.I had to re-work all of them for one reason or another (4-pack). There seems to be no evidence of flux anywhere, and the solder used seems like very bad quality. Micro components seem to be on there good, but it's obvious that the larger components are picked, placed and soldered by hand, and not by anyone who has experience assembling electronics. The 1000uf capacitor on one of them was soldered so high that it was in a twisted/shorted configuration when I received it.Part of the reason why folks like me buy these things is to save time. I spent about an hour re-working these-- true it's a time saver over having to buy, pack and assemble, however not by a ton.In any event, I wouldn't buy from this seller again due to the lack of any kind of assembly QC. I think some things can be damaged in shipping, but considering the way these were packed, I don't think they were damaged in transit.Other problems encountered were:- Loose heat sink on LM2956- Components mounted very high on leads, able to bend and twist.- Cold solder joints- Heat sinks not soldered to mounting pads- Solder bridges

I needed to power a WiFi Arduino project. I needed 5V dc for the ESP32 and 24V AC to drive spinkler valves. So starting with a 24V AC step-down power supply I used this AC/DC module to get my 5V DC. I've been running the project 24/7 for a week now without issues. This is definitely a cost effective solution. I was surprised how easy it was to dial-in the 5V. I was expecting a cheap potentiometer requiring micro-movements, nope, adjustments are smooth. The heat sink doesn't appear to get very warm so my current draw doesn't appear to be taxing this unit. I've remeasured the voltage output after a week's use and it's still stable at the set voltage. I'll post an update if reliability changes. Right now it's a five star buy.

Used to add an 18 watt LED light to a Craftsman snowblower. Converted AC (yellow wire on snow blower) to DC. Connected a multi-meter to DC side and adjusted output voltage to 12 volts DC. Worked perfectly. No flicker at all regardless of engine speed.

Very easy to use and small enough to hide in a model diorama.