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..
I organized the materials into two categories, necessary and optional components. The prices are based on what I paid or the lowest price I could find on ebay. Normally I buy components from HK. With most of the electronic components you can buy about 10 units for the price of one in the UK. The links to ebay are the cheapest I could find.
Total so far £9.66
Grand total of only £12.12