Review on Pack Of 10 Dorhea MT3608 Boost Power Converter Modules - Adjustable Step Up Voltage Regulator Board With Micro USB - Convert Voltage From 2-24V To 5V-28V Output For DIY Projects And More by Jerry Olson

I appreciated the size and low cost, but I felt the choice of the adjustable trim potentiometer on the circuit board was not suitable for the task. At first, I thought that all the boards were defective, because all they did was track the input voltage, not boost it. You had to turn the adjustment screw about twenty times counterclockwise before it affected the voltage. I assume that these are 25 turn Bourns 3296 (10 3) 100,000 Ohms trimpots (figure 1). Admittedly I am not an engineer, but when only the last 2 or 3 turns on a 25-turn pot are useful, then it's my opinion that the wrong pot (meaning the incorrect resistance) was chosen. I noticed that on one of the other voltage regulator boards that I purchased at the same time has a 10,000 Ohm trimpot (figure 2), and has a more useful range of the trimpot, although I realize it depends on the entire circuit. But I think you get my point. (I'm not sure I understand one of the comments about having to push the trimpot screw in to get it to work. I have not had this experience with trimpots.)