When designing this power supply, my objective was to have it as portable as possible, so you can take it almost anywhere. One of the reasons I want it to be so portable is because every time I go to visit my family and friends abroad, they always have something for me to fix (or at least “try to fix” ) They have a soldering iron, but that’s about it. That’s why I made the voltpen, this mini power supply, and a mini usb sound card oscilloscope (Instructable to follow soon).
I made other power supplies, but none of them had current regulator. This time I decided to use the LM2596 instead of the normally used LM317 or LM350, so I could also adjust the current.
The beauty of this unit is that you can connect it to any DC source from 7.5V to 28V. So I can just take it with me and connect it to a laptop power supply for example. The output voltage will be very close to the input voltage, maybe about half a volt less. It can also be use as a voltmeter without being powered for voltages from 2.5V to 30V and as an ammeter from 5V. And It’s great for charging batteries.
Enough talking, lets cut to the chase..