5Pack LM2596 LM2596S DC-DC Step Down Variable Volt Regulator Input 3.0-40V Output 1.5-35V Adjustable Buck Converter Electronic Voltage Stabilizer Power Supply Module

Works great!

Ok these work great - stable output. HOWEVER, I thought these did not work at all - adjusting the screw did nothing except show a stable 11.5 volts. BUT, as people said in their positive reviews, turn the screw counterclockwise FOREVER and the voltage will eventually go down (up in the reverse once down). There is an LED indicator that lights up blue but drops as you get to ~ 2 volts. So turn the screw counter-clockwise until the LED dims, then check with a meter and adjust. Best of luck! These work great, once you are are done screwing around with the screw!

Just reordered another 5-pack of these. They have been very convenient to add to all the unregulated AC/DC power supplies I've accumulated over the decades, saving lots of $$$ on projects. I haven't had a problem with a single one so far. Read the other reviews about how far you need to adjust that screw counter clockwise (it's A LOT!) Great to power all kinds of projects like Arduino, RPi, LED lights, all kinds of things for 3D printers, etc. I specifically bought this to use with a lion jump starter battery that does not have a feature for continuous, regulated 12v DC output from the ec5 port on the side. By connecting the input on the LM2596 regulator to an ec5 connector, I can use it in place of the included proprietary jump start adapter to get an constant 12v output. It's great to power a telescope, ham radio, small inverter (for a laptop, etc), or anything that uses < 2.5-3 amps (rated output for the LM2596), and of course, it can be adjusted for any lower voltage output as well.

bought these to change voltage for my costume project. somehow, between buying them and actually putting one to use, it slipped my mind that these are only for lowering voltage, no boost. I then tried to get them to change 3.7V to 5V. failing at that, I contacted the seller and they referred me to the description where it clearly says 'no boost'. a big DUH! on my part! at any rate, I then used them to go from 9V to 5V and 3V. they are quite easy to hook up and to adjust for the desired voltage. not sure how I came to try one to ho from 3V to 5V as all the rest of my batteries are 9V. some kind of brain fart or senior moment. at least when the seller responded to me they didn't call me on my big doofus move. they simply pointed out the error of my ways!good product and excellent seller!!

Tried to use these to slow down the water flow of my kitties water bowl because it was splashing water all over my floor. Rather than slow it down it would just adjust from full on output to full off. no variable voltage coming out. they were all like that. I did not return them.

Apparently these come with a light? I had no light on any of them, confirmed polarity correct and voltage in @ 12v, found output less than 0.2v and no change when maxing out trim pot both ways til it clicked, unfortunately I didn’t get a chance to use them within the return window so I’m out of luck. Some of the regulators input capacitor got extremely hot within seconds and other ones didn’t get warm at all. Some had absolutely 0v out and others had 0.1-0.2v out and I’m not joking when I say I maxed the trim pot out both ways

Tiny little thing does exactly what it needs to do. Pot is very smooth, voltage is stable.

Works perfectly. I used it to attach 4v Xmas lights to a 9v battery pack. Just have to turn the adjuster a lot to get the desired voltage.