5pcs JacobsParts MP1584 3.3V Fixed Output 3A DC Step Down Converter Buck Module 4.5-28V in

I've used these in many projects and they perform very well. They are advertised to work with input voltages from 4.5 to 28Vdc with a fixed output of 3.3V. Note that these are step down converters and to test the output voltage, there must be a load attached. With no load, the output will approach 4 Vdc when the input voltage is less than 5.2V or so.

Good product

Crazy tiny which makes them extra easy to use. I used a few to regulate voltage to interior LED lights I installed in my car so that they didn't pull direct ~13.5v since they were a bit too bright and got too hot. It is very nice to be able to just turn the potentiometer to set the lights to a desired output. With the LEDs pulling about 1A at 10V the driver seems to be working flawlessly and I even noticed that because its fully regulated the small fluctuations I noticed in the lights before have completely stopped.On a side note, there is absolutely no reverse polarity protection. One fried instantly with a tiny zap when I accidentally plugged it in backwards.

Pros:Truly tiny, and seem to fit on a breadboard.Works for smaller currents.Cons:I tried driving a digital LED strip, and while the module seems to work fine, it gets waay too hot. I can smell the heat after about 1 minute of continuous operation (At 5V, 1.45A). The other one that is driving an ESP32 and an audio player/amplifier module works great with no heat. The ESP/Audio setup is drawing anywhere from 10-30mA (I didn't test with Audio playing, though. Likely it would have similar results).They also seem to have a small amount of high frequency noise, though this isn't an issue in most cases.If you just need a tiny module to power something that draws low current, this is perfect. If you need more current, get something beefier.

I do a lot of sensor/microcontroller experiments and I had been using adjustable versions of this regulator. The adjustable ones can be challenging to tune to the right output voltage as small movements make big swings in output voltage. These are really plug and play for 3.3v projects. Way faster and no worry of bumping the pot and changing the voltage accidentally. Of the 5 or so that I have used so far, they all have put out between 2.9 and 3.2 volts when fed 12-13 volts from a solar charged battery. For my application, the variance is not an issue, but do I recommend testing each with a multimeter before using in a project to make sure it will meet your needs.

I've tried a bunch of 5V buck converters, to power the Raspberry Pi Zero 2W in the autonomous toy car I built. This is the best. Stable, handles fluctuating load and fluctuating supply (supply is also driving the motors, so it varies a lot). And they are inexpensive.

Bought the 10 pack of adjustable buck regulators for a LED lighting application. You get what you pay for in this case. These are so terrible! A quick test on my work bench proved just how bad...I tuned it for 5V(no load), 12V intput. At only 0.5A load these exhibit > 1.0Vpp ripple at 340 KHz! BAD! The regulation dropped to 4.4V average... So I turned it up to 5V. (was then 7V at no load)Things only get worse from there. At 2A, it started to cut out periodically. The thermal camera showed the chip as the hottest part, about 70C on the surface. The ripple was now at 2.5Vpp (now at 160 KHz). Unacceptable junk. I will try to see how much cap is needed to make these work.The efficiency is only marginally better than a linear regulator. Nowhere near 90%, much less than advertised. Cap will not help this.So, they got my money. I'm only out 6 USD.

I'm using these to replace the onboard regulator on ESP devkits, so I can run them at 3.5ish volts, and charge a lifepo4 battery. They're awesome. None of mine even get warm running ESP32s and ESP32-S3s with wifi etc. Their outputs appear rock solid on my multimeter and I've had zero problems so far. Just beware the potentiometer for voltage adjustment can be really sensitive.