Eiechip DC-DC Step Up Converter - USB Power Module, 2V-24V to 5V-28V, 2A MT3608 Micro USB (Pack of 10)

They work great and are super handy little boards, have used like all of them in various projects

Great Product, Great price and as important Great Company to Deal with (package got rough handling and three ferrite inductors were broken and issue was graciously handled by Putian Xiuyu Duoyu Trading Co. Ltd.JUST REMEMBER TO TURN THE POT 15 CW 'LAPS' before powering.Great device, tried in several circuit ideas.Already packaged one to convert 110V led gooseneck lamp to battery operation for safety (no cords) Lamp is mounted to mini parts sled on table saw. Hacked LED series strings for multiple 24V strings and added 1/8 W resistors to lamp The Boost converter ran without hesitation or much heat at 24V 1A until battery cuttoff engaged, about 1.9 hrs. More time than I need to spend on saw at one session. LEDS did not flicker or show any light artifacts from boost converter (used as received - directly connected to battery manager module. Because of low heat, just used board attached to enclosure as heat sink. Easy Peasy.Bob

I use these in quite a few of my electronic projects for stepping 5V usb up to 9v for battery replacements or for stepping 3.7v cells up to 12v for using car based products from a pack of 1s 18650s or similar cells. These get quite warm so i dont recommend using them hard but for some LED lighting or similar they could be useful. I like that i can choose between using Micro USB for power in or soldering directly to the board. I wish they offered a USB C variant for more modern compatibility.They can be noisy if you intend to use this for powering audio devices i would be careful due to ground loops possible leading to bad electronic noises. This isnt their intended use but i figure i should mention because i did try it with no luck.Image shows powering a single section of 12v light after adjusting the voltage for a 5v input from a USB power supply to get 12v out.

Pay attention to the reviews that say "15 clockwise turns before using"! That's the direction that INCREASES the voltage (to about 28V), and it will start clicking when it reaches the end of travel. Then you can turn back down to the voltage you want. I turned one the other way just to see what happened, and it smoked. Poof. That's either because the trim pot shorts something out OR because I dialed in less than a 2V boost (which the spec says is the minimum). For example, you can use these to supply 5V from 3V batteries, but NOT to regulate a 5V supply. I'm using it to boost USB voltage to run a 12V delay relay (item B07BT25J52), which works great. Couldn't find that exact functionality in a 5V delay relay.

Let's be real. These are tiny cheap boards. But they work pretty great. Hook it up to your supply voltage, and start turning the potentiometer.They also work all the way down to ~2.1v! (I needed 2.4 volts so these were perfect!)There is one big caution though... they cannot be run in parallels to increase the current. It doesn't matter how well you tune the potentiometer, or if you physically solder the inputs and outputs in parallel. So if you need more current, you'll have to keep searching. At around 2.2A they start blinking.

I'd give these -5 if I could. These blow up easily and when they do work, the output Voltage drifts. I'm using them in low power applications which should make them more stable, but not these units. I would gladly pay $5 or even $10ea for high quality boost converters in this size. But these are absolute junk. I will be making my own for my applications from now on.

I have read reviews stating that some of them didn't work. I have not had this issue. It is important to follow the directions and turn the control screw clockwise at least 15 times before powering it for the first time. After that just turn the screw clockwise or counterclockwise to your desired voltage using a multimeter. I found it easy to solder my leads to the unit, and use my multimeter to get the desired voltage.

I probably shouldn't complain given the ridiculously cheap price of this unit. The vaguely worded output is claimed to be "5V-28V 2A." To me, that should be able to handle 12 V at 0.8A. I followed the 15 turns on the pot per instructions. Provided 5V input via the micro-USB connector. Used the pot to set the voltage to 12 V under no load with my multimeter. Then attached a 12V blower that draws 0.75 A, and it ran, but the blower seemed underpowered based on sound and feel. Checked the voltage and it had dropped to 11.1 V. Very slowly turned the pot on the unit to higher voltage to try to get back to and the unit could not get back to 12V. Voltage started oscillating wildly. Repeated this multiple times with the same results. So, for the price, I think you get what should expect, but not exactly what you paid for. To my surprise, I then tried this other unit from Amazon, and it did the job: https://smile.amazon.com/gp/product/B074R7FDCR/ref=ppx_yo_dt_b_asin_title_o03_s01?ie=UTF8&psc=1