I came across this web page with some very interesting Joule Thief designs and I thought I should pass it on to others. If I can find the place, I’ll also put it in my home page.
When I started building my LED voltage boost flashlights back in the 2001 to 2003 years, we were afraid we might get caught in an elevator with no light during one of the rolling blackouts that the power companies were telling us might happen. I had a number of small flashlights, mainly the Mini Maglites, but I wanted something that used a LED that would not burn out if it was used for a long time. I started building flashlights into Altoids tins, but they were too big for the pocket. That was when I started investigating smaller flashlights using a single AA cell and some kind of circuit to make the 1.5V drive the higher voltage LEDs. That was when I developed the circuit that I put into the Velamints tins. Here is the inside. Another one is shown here. It’s on the top of the second pile from the left.
The pile shows several of the others I built during the Energy Crisis in California. At that time you could not buy a LED flashlight at the store; then when the first ones came out, they were fifty or more dollars, so almost no one could afford them. About the only way to get one was to make your own. So I made my own. What I’m alluding to is that my Joule Thiefs were born of necessity and practical needs. So the art factor really didn’t come to my mind. Nowadays, a LED flashlight is available at every store for a few dollars, and I think the art part of a Joule Thief gives it a more noble reason for its existence.