Introduction: Ferrite, the Joule Thief

Picture of Ferrite, the Joule Thief

This was one of my joule thiefs I made.  Ferrite will come on at night and light the way so i don't trip and bump.  Power is supplied by a dying battery that gets a rest during the day. Other Joule Thiefs I have made.


FerriteGiant (author)2016-06-25

Nice addition with the light sensor!

Dave Kruschke (author)2012-06-18

There is a newer way of making this "Joule Thief" that doesn't require going to the trouble of finding a toroid and putting windings on it. The toroid, transistor and resistor can be replaced by a simple inductor and four legged IC. See

cqaigy (author)2012-03-25

Must be hundreds of ways to do this. I love your artistic addition to the genre. Well done.

fobot (author)2011-09-06

I plugged 11 leds into a 9V battery 3 weeks ago and its still on. Can you explain why this is special?

iamdarkyoshi (author)fobot2012-01-07

its because joule thiefs have the capabilities of powering a 3-4.5 volt led off of 1.5 all the way down to .3 volts. works great for the batteries just normally thrown away. i made a couple and they work fantastic, made of only like 4 parts :D

loki2012 (author)fobot2011-11-23

Bad day fobot? It is special because he built it. No claims to be the best or most efficient. Just a night light running on a battery, built into art.

About This Instructable




Bio: I like to tinker and experiment with electronics, robotics, programming, and photography. Along with my latest interest in Steampunk.
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