DIY variable power supply from a laptop adapter
In this video I show you how you can reuse an old laptop power supply and turn it into a variable power supply. In this project I used a DC-DC converter, a voltage-, and current meter with a display, a mains switch and two 10 kOhm potentiometers. I put everything together in an enclosure and now I have an adjustable power supply with 20 V and 4.5 A output parameters. Conversely to the popular SZBK07 DC-DC converter, this one uses a 10 kOhm resistor instead of a 100 kOhm to adjust the voltage and the current.
A schematic drawing of the connections between the input voltage coming from the laptop power supply, the DC-DC converter, the voltage-, and current meter and the load. Keep in mind that the maximum voltage for the DC-DC converter I used is 32 V and for the meter is 30 V. If you use the converter for high current applications, make sure that you actively cool the heatsinks with a fan.
