6 Pack LM2596 DC to DC High Efficiency Voltage Regulator 3.2-35V to 1.25-30V Buck Converter DIY Power Supply Step-Down Module

So far, so good. I bought a six pack of these voltage regulators. The first one I hooked up I messed up and reversed the input voltage. This immediately smoked the regulator; so beware that there is no reverse voltage protection on the input. This was completely my mistake, and not an issue with the product. I hooked the second voltage regulator up to my test setup, and it worked great. I used a 32VDC power supply salvaged from an old HP printer as the input supply. I tested the output with a high power 2kohm resistor. I was able to adjust the output voltage to a steady 12.00 volts according to my digital multimeter. The input voltage remained approximately the same as before I connected the output load. Then I switched the load to a small DC motor with a gear train attached. The voltage output remained very stable at +/- 0.01 volts from the 12.00 volts I had set with the resister test. Overall I'd say these are inexpensive and very nice little voltage regulators, and a good value for the money. I intend to add a little voltage meter and build a little benchtop power supply with this one.

These work great and I'll probably buy more eventually for other DIY projects

This voltage regulator works well and delivers stable output, but you definitely need to factor in heat depending on your load. At lower currents it performs great, but as the draw increases, so does the temperature. - Below 0.5A: it stays warm but never gets concerning - Around 1–2A: it becomes hot to the touch - Near 3A: it can overheat unless you have good PCB copper area or proper airflow As long as you design around the thermal behavior, it’s a reliable little converter. The performance is solid for the price, but the heat characteristics are important enough that I knocked off one star.

Did what they were supposed to do, but they do have to be adjusted with a load attached. I wasn't able to fine tune the voltage until after I put a load on it, but after that I found it easy to adjust. Though it took a lot of turns until I saw a change. Just use a bench power supply set right above your target voltage and adjust the buck converter down until you see the output voltage drop, then raise your bench supply to your target input voltage and readjust for your target output voltage. These do automatically handle changes in input voltage while maintaining a stable output voltage. Used approx 11mA @ 12v input w/ no output load. Tested with a 0.5 steady, 2A periodically spiked load and maintains a stable voltage without getting too hot to touch. I did install thermal tape connecting it to the chassis for extended operation.

Not what is shown in the picture

Very handy for down converting 3.7v lipo to 3.0 or lower to replace AA’s. I used one with a 500mah lipo bag to convert a Quasar headlight used on high quality head band type Donegan magnifiers from dual AA’s. The battery, regulator, on/off switch and pigtail for recharging wound up 4” long and all fit on one side.

Use these as step down transformer to power 5V LEDs from 12V source. Cheap solution.

Another foreign made P.O.S. that has to be returned . The unit simply does not operate . it sends the high input voltage straight to the output without any sort of step down . This happens no matter where the adjustment screw is set at . This occurs regardless if the "regulator" has a load attached at startup or not . In short its an expensive piece of wire ....not a voltage regulator !