10Pcs Step-Down Power Supply Module Mini DC-DC 12-24V to 5V 3A Voltage Buck Converter Adjustable 1.8V 2.5V 3.3V 5V 9V 12V

And fortunately, I do have a microscope, although a magnifying lamp may work too.The boards that I received had been separated and were individually wrapped. They come with the adjustment pot connected. I wanted to set it for +5v out. Therefore, I had to cut an extremely small trace to separate the adjustment connection, and then connect the +5v connection. I had originally planned to use a piece of AWG 30 wire to make the connection. However, as it turned out it was very easy to make the connection via a solder bridge.The board worked perfectly and the output was very close to +5v. You won't be able to use it as a reference voltage, but it's perfect for powering circuits, which is how I intend to use it.They work perfectly for my application. I recommend them.

I'll admit, it was incredibly frustrating that these came with no instructions. There are multiple comments of people not knowing how to use these. After knowing which copper trace to cut, it is fairly simple.The accuracy is appropriate. For example, the "1.2v" is 1v - 1.8v; the "3.3v" comes in between 3v and 3.9v.BUT... considering the price. These converters are well worth it. Spend $100s on something professional grade if you need professional. These chips are great for prototyping and tinkering.Lacking instruction - yes.Cheap - yes.Completely accurate - no, but within reason.Purchase again - yes.

It might have been me but I have not had any luck getting these to work the voltage is always the same

Without instructions this is not a module for those who don't really know electronics. Other than that it's pretty straight forward. Make sure the input voltage is higher than the desired output voltage. It's step down, not step up. Don't pull more than 3 amps, probably can't do that either without heat sinking or cooling it some how. Also the adjustment pot is not very good. One board was really unstable with the pot. If you want to use the fixed output option you must cut a trace, the adjustable option is bridged with copper. Cut that, then solder bridge the option that you want.I have tested two boards. The fixed output voltages ran 1% low. Not going to hurt anything. I just want to see 5.0 volts, not 4.949V. Once I get a load box set up I'll take some more measurements.For those wanting to know it is based on the MP2315 IC, made by MPS.

I have 15 of these in use. I cut the line from the ADJ trace using a razor blade and soldered the pads between 5v and 3.3v as needed.

How to wire it would be really nice to include!!.

Pros: This does pretty much what I expect, plus it's quite small.Kind-of-cons: I had a noisy 24V DC supply, and it fried two of these (30V peak). These can fail in a short circuit condition so, fuse up.Note that adjustable voltage is already selected by a jumper on the back, and it is very difficult to see w/o a scope. If you want fixed voltage, cut that jumper and bridge a jumper for the voltage you want.

But needs instructions, Although it is easy to find the instructions online I rather post a similar one here for other buyers.