Joule Thief

Today I get an email from my sister asking if I have an LED that can be powered by only 1volt. I've seen LEDs that work at 1.5volts but they aren't very bright to begin with so they probably wont be visible at 1volt.

Immediately I thought, hey a Joule Thief might work. I've been hearing about this circuit often on Hackaday and Make but never attempted to make it.

I dug a broken xbox motherboard and pulled off the torroid and I had a bunch of transistors leftover from my senior design project last year. Wired it up and powered it by 1 AA that my wireless mouse tells me is dead...

My meter shows 1.132 volts, yet it lights up the blue LED strong!

edit:

Still going strong at 0.947volts

edit2:

Still blinding at 0.786volts