What do you do if the power is out and you need to charge your cell phone to make an emergency phone call? Don’t worry. There are plenty of potential power sources all around you. One of them is the phone line. In this instructable, I am going to show you how you can use the phone line to power your small electronic such as your phone or other USB devices in an emergency.

Note: This project is intended for emergency situations only. Please be aware of applicable laws regarding phone lines in your area.

Jason Poel Smith

Jason Poel Smith

My name is Jason Poel Smith. I have an undergraduate degree in Engineering that is 50% Mechanical Engineering and 50% Electrical Engineering. I have worked in a variety of industries from hydraulic aerial lifts to aircraft tooling. I currently spend most of my time chasing around my new baby. In my spare time I make the how-to series "DIY Hacks and How Tos."


  • robert

    Very nice Jason, good information to know, I work in telecom and use “our” line voltage to charge various pieces of test equipment, including cell phone when needed. Current on standard home service usually runs between 20ma and 30ma, so nothing scary there, but works in a pinch. And yes good advice about using diode for ring AC voltage. We do our best to keep power up during outages, and would not blink twice for someone using it for their well being.