There’s perhaps nothing harder to throw away than a good power supply. Whether it’s the classic “wall wart” whose mate has long since been misplaced or a beefy ATX you pulled out of a trashed computer, it always seems like there should be something you could do with these little wonders of modern power conversion. So into the parts bin it goes, where it will stay evermore. But not for the [TheRainHarvester], who figured out that the secret to putting a drawer full of old laptop chargers to use was combing them like hacker Voltron.
Using three old IBM laptop chargers, he’s able to produce up to 48 volts DC at a healthy 4.5 amps. His cobbled together power supply even features an variable output, albeit with some mighty coarse adjustment. As each charger is individually rated for 16V, he can unplug one of the adapters to get 32V.
In the video after the break [TheRainHarvester] walks viewers through the construction of his simple adapter, which could easily be made with salvaged parts. Built on a trace-free piece of fiber board, the adapter consists of the three barrel jacks for the chargers and a trio of beefy Schottky diodes.
The nature of the barrel jacks (which short a pin once the plug is removed) along with the diodes allows [TheRainHarvester] to combine the output of the three adapters in series without running the risk of damaging them if for example one is left plugged into the adapter but not the wall. He’s also looking to add some status LEDs to show which chargers are powered on.
Unfortunately, [TheRainHarvester] realized a bit too late that what he thought was an inert piece of board actually had a ground plane, so he’s going to have to come up with a new way to tie the whole thing together on the next version which he says is coming now that he knows the concept seems workable.
In the meantime, if you’re thinking of hacking something together with the wealth of old laptop chargers we know are kicking around the lab, you might want to take a look at our primer for understanding all those hieroglyphs on the back of the thing.