Has your phone or iPod ever died when you needed it the most? Design a quick mini battery charger for your small electronics! Plug your device into the USB port, turn it on, and you're all set! Lots of electronics are powered from a USB cable, so a powered USB port would be the most useful power source. Using a voltmeter to measure the voltage on each pin of an iPod AC Adapter, it shows +5.16V on the V+ pin, +2.06V on the D- pin, and +2.76V on the D+ pin. We'll use a 7805 voltage regulator to get +5V for V+ and two resistors for each data pin. I calculated the resistor values to minimize current loss (as not much current needs to go to each data pin). You may also calculate different resistor values if your device requires more current. Note that newer phones have much larger battery capacity and may not be able to provide enough current to charge the phone.
Visit the Jameco workshop page for the original build. Current instructions are available at the top of this page.
NOTE: The Altoids tin is not included. We recommend this tin flip-top enclosure, P/N: 2157896.
Product Compatibility: This will work for some early generations of iPod and iPod Nano (up to 2nd gen), but not all.