Wall warts are transformers that convert AC to DC power. They sometimes have proprietary plugs and are designed to output very specific voltages. Inevitably, they find themselves piling up after the original gadget has been disposed of. It doesn’t make sense to throw out a wall wart, right? It might come in handy. This mindset results in boxes and bags of old power supplies lying around.
MAKE friend Chris Connors shows how to modify a wall wart to equip it with alligator clips, giving you the ability to power a project breadboard right from the wall socket.
10 thoughts on “How to Create a Power Supply out of a Wall Wart”
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Also, how to create a hammer out of a tool for pounding nails.
Love it.
A whole lot more interesting would be to open up a SMPS type wallwart, figure out the control chipset, and after downloading and looking at the datasheet, upgrade the cheap Chinese caps which would probably fail before long, add back in the chokes the manufacturer left out to save money, adjust the feedback resistor to produce the voltage you need (assuming all the other components are up to spec) or even put is a variable resistor to make the power supply adjustable.
There is alsmost always a voltage divider connected between the DC output and a feedback pin on the switcher IC. Change the resistor ratio and the output voltage will change.
This was a pretty weak tutorial – should have been called “How to solder an alligator clip onto a wire”. Most wall-warts I have seen have terrible voltage regulation – I’ve seen some that were essentially just a transformer, a diode, and a cap. The voltage varies widely, and is highly dependent on load. I was hoping to see an article on how to maybe add a few components to turn this into a semi-reasonable power supply, rather than just a random voltage generator.
I’m sorry you are not really making a power supply, because it already is one. He just added alligator clips to the power supply.