“In this instructable we will make a portable, variable power supply, using a step down buck converter, three 18650 cells, and a 7-segment display voltage readout. The power output is 1.2 - 12 volts, though the led readout cannot read below 2.5 volts. Let’s start with the needed supplies.
Supplies:
Sep down buck converter, LM2956
Panel mount multi-turn potentiometer, 10k
Three 18650 cell battery holder
x3 18650 Lithium-ion battery cells
Panel mount push button, momentary
Panel mount on/off switch
Panel mount led display voltage readout
Screw terminals, 3 pin
3 screws, 2 small 1 larger, exact sizes based on your components, detailed later
3 nuts, I per screw
8 washers, 4 for each of the smaller screws
Teflon wire (easiest to solder to but any wire will do)
Project box, 3.15 x 1.97 x 1.02 inches
Electrical tape
Tools:
Soldering iron
Solder
Wire strippers
Wire cutters
Hot glue gun and hot glue
Desoldering iron or desoldering wick
Pencil
Razor blade”